Research on the efficacy of the CorePump® Machine

COREPUMP® Machine 

Research Abstract:  User Efficacy

Introduction: For Decades the fitness industry has presented new products for the purpose of creating an enhanced strength training experience for performance, convenience and price point. Often, devices specialize in muscle isolation or incorporate the entire body and are generally expensive and require numerous parts to arrange, and a significant amount of space. Over time the drawbacks have led to disfavor and lack of use. Fitness facilities that promote muscle isolation machines are expensive to join, are generally not convenient due to time or location.  Free weights require a heightened level of understanding or instruction, and pose a greater risk to reward ratio, which is especially true for the older population.  Finding a device that addresses these concerns yet provides an appropriate experience is what prompted this research project.   

Purpose: The CorePump® Machine represents a new type of training device based on Isokinetic resistance.  There are three types of resistance training. 1) Isometric: muscle contraction without joint motion.  2)Isotonic: muscle movement in both concentric (shortening) and eccentric (lengthening) phases.  3)Isokinetic: muscle movement with resistance in concentric only phases.  Numerous research studies have shown isokinetic training to be a viable and potentially safer method of strength training.  This study was designed to determine the benefits of this device for an individual in a private or group setting.  

Methods: A random group of 25 physically active adults from cycling, running and swim backgrounds participated in the study. A single page questionnaire was provided prior to use of the CorePump® Machine. A workout consisting of 8 fundamental movements involving 1 set of 10 reps for each was then completed.  A second single page follow up questionnaire based on the experience was provided after the workout with CorePump® Machine.  

Results:  Pre workout questionnaire: The majority of participants reported they were currently participating in a resistance training program (60%); with 72% participating throughout the year.   With 84% of the participants reported not utilizing a personal trainer during resistance training.  80% responded that they weight train less than 1 hour a session with 36% reporting time as the limiting factor.  Although 88% did not fear soreness in their resistance training, 68% preferred not to be sore from resistance training.  

Post Workout questionnaire: Upon completion of the 1 set of 10 repetitions for 8 separate movements, 96% of the participants felt the CorePump® Machine was sufficient to include all body parts.  Only 4% of the participants felt new or unusual soreness after using the CorePump® Machine (preexisting conditions).   The majority of participants had a positive encounter with the CorePump® Machine; with 80% feeling confident they could use it alone.   68% were interested in purchasing and also learning more about the CorePump® Machine experience. With the majority of the participants expressing that the product presented value; however, 88% felt the price point exceeded their expectation.  

Discussion:  Overall, the participants had a favorable experience and felt it would be a useful form of resistance training.  Those who didn’t have a favorable experience commented that the resistance, even at setting 1, was too difficult.  In some cases, the machine did not allow for appropriate range of motion but this was due to only having one size model to test.  Others commented that going to a facility to workout had a social aspect that had not been anticipated and thus those participants would not likely purchase for home use.  Most felt safe using the machine and were confident they could control form while using it on their own.  

Conclusion: The use of isokinetic resistance training is not well known to the average end user, and there is a paucity of research available to support its validity.  As a result, more research is needed, but the current project would support favorable results, and outcomes across a broad spectrum of ages and abilities.  The CorePump® Machine represents a viable method of isokinetic resistance training to meet the users end needs.  

Jeff Lockwood, LifeSport (Exercise Physiologist)


Home Health Plan For ALL

Colby Health Institute (CHI)

It is the duty and responsibility of our government to provide each tax paying citizen a better solution for health and well-being. This should be implemented in the privacy of our own homes. This should be at no additional cost to the taxpayer, but to be paid for by our government. Better health and well-being must start in the home.

George Bernard Shaw wrote, “Youth is the most precious thing in life; it is too bad it has to be wasted on young folks.”

This is a sad truth.

The paradox of it all is that we sacrifice our time and health in the pursuit of wealth and at the end of our journey, we spend our wealth on the pursuit of better health and more time.

Sadly, I’ve known many individuals who’ve attained millions of dollars but are left sick, unhappy and alone.

Simply put, our health is our wealth.

Pain Is To Inflame
Where  there is fire, there is smoke. The cause of the fire is not as important as the fact that there is a fire. When our bodies have a disease we are inflamed. I will briefly simplify the two words “disease” and “inflamed.”

Dis-ease: Not at ease.
(A disorder of structure or function in a human, especially one that produces specific signs or symptoms or that affects a specific location and is not simply a direct result of physical injury. Whether your body has a broken bone, a virus, bacterium, Cancer, or any other disease it will have inflammation.)

In-flamed: Fire within.
(A localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful, especially as a reaction to injury or infection.)

Nearly 75% of all deaths in the United States are attributed to just 10 causes, with the top 3 of these, accounting for over 50% of all deaths.

Heart Disease
Chronic lower respiratory disease
Alzheimer’s disease
Influenza and pneumonia
Kidney disease

80% of these causes of death are preventable and treatable with exercise.

Movement is medicine, even small doses extend longevity and can prevent and treat disease. Movement truly is a polypill. Thinkers of ancient times, such as Hippocrates and Plato, suggested that physical activity was good for health.

The epidemic that has scourged America can be solved by simply eating healthy and exercising daily.

I wonder why the majority of Americans avoid exercise like the plague?
I believe because it is hard work and takes up so much time.

If each American had a simple, user-friendly solution for medicinal-movement that respects our time, we would beat the diseases that are killing us.

Motion Is Lotion
Not all movements are medicinal, some are very inflammatory and dangerous. If you are currently in a fitness program that leaves you injured, abandon it immediately!

Not all resistances are created equal.

A brief explanation of isotonic, isometric, and isokinetic.

Isotonic exercise: Exercise when a contracting muscle shortens against a constant load, as when lifting a weight. This is the most popular form of resistance today. Cross fit has been ridiculed for creating such a dangerous fitness program. 80% of cross-fitters get injured within the first 60 days of starting.

Isometric exercise is when muscular contractions occur without movement of the involved parts of the body. Think Bruce Lee pushing on a wall that doesn’t move.

Isokinetic exercise is a type of strength training. It uses specialized exercise machines that produce a constant speed no matter how much effort you expend. These machines control the pace of an exercise by fluctuating resistance throughout your range of motion. I am proud to introduce the CorePump® Machine.

I had a discussion with a very knowledgeable exercise physiologist (Jeff Lockwood with LifeSport), and we were discussing the best methods and practices for training high-level athletes. The ideal training situation for an athlete is to build strength, power, and endurance for muscle groups specific to their sport. Consider a cyclist, the athlete will have to optimize their capacity to ride more efficiently and effectively while refining and fine-tuning their skills specific to their sport. This takes a lot of time and practice. To be the best, you have to beat the best.
In order to beat the best, you must be faster and out-perform your opponent. You need to be the better machine. This is done by increasing strength, flexibility, and endurance. Simple as that.

Using traditional forms of resistance, you will suffer from DOMS (delayed onset muscle soreness). This is a condition that will require much-needed rest in order to fully recover. This takes time away from the athlete for optimally training and performing.
Using isokinetic resistance will strengthen all the necessary muscle groups without getting blasted with DOMS.

This will give the athlete more time to refine their skills in order to be victorious over their opponents.

This applies to life athletes as well. You and me.

The solution for better health and wellness is finding a method that will not take up very much time and space, yet still effective in preventing and treating 80% of the causes of death.

Love One Another
Often I think about what thoughts run through people’s minds at the end of their journeys, here on earth. When transcending from mortality to the unknown, what common thoughts race through the minds of the departing? I would guess one thing that never gets a second thought would be “how much money do I have?” An idea that consumes the majority of people their whole lives long. It’s amazing and somewhat unsettling that we have put so much time and energy in the pursuit of money. If we only get one life to live, why have we succumbed to this nonsense? Can money truly buy happiness? I think not. Just ask the departed.
I think people ultimately put their conscious-energy into thoughts like have I loved? How have I been loved, in return?
Just like earning monetary wealth, earning love takes time, energy, and consistent-persistence.
Unlike the pursuit of money, the return on love is much more fulfilling, and the dividends are truly out of this world.

Every fitness regimen should meet one common goal: improve strength, flexibility and cardiovascular health and function.
These 3 components of health are what we call the 3 pillars of fitness.
I am pleased to announce that I have created a solution that will make the world healthier without taking up a lot of time and space while achieving optimal health.

Younger Tomorrow: The Art of Recovery



An important source of confusion surrounding the use of the term recovery derives from the lack of clarity about the respective roles of healthcare professionals and people with mental health problems. Recovery is a process of change through which individuals improve their health and well-being, conduct their lives autonomously and strive to reach their full potential. Recovery-oriented care is what mental health treatment and rehabilitation professionals offer to support the person's long-term recovery efforts. The promotion of well-being through self-care and early intervention, both mentally and physically, is an important component of it. Recovery-oriented care requires that people in recovery be involved in all aspects and phases of the care process. This book clarifies the terminology and discusses some of the ways in which recovery and recovery-oriented care are commonly seen from the perspectives of practice. Thus, I defend that the person "in recovery" must remain at the center of all conceptualizations and debates, as well as the need to consider culture in the configuration of how recovery is seen and promoted in different societies. We believe it is necessary to promote this approach with cultural adaptations and include it in health schools and residency programs. Thus, students and future health professionals will know the model and can decide on its integration in daily practice.

Today, our society is characterized by a high-tech and industrial economy in which the principles of economics increasingly influence all areas of life. Productivity and performance thinking determine not only the working world but also the private life. The increasing demands are leading to a stress-ridden society in which it is increasingly difficult for every single person to find or maintain a personal balance. The consequences are mental disorders such as depression, anxiety disorders, and fatigue. A sense of emptiness, coupled with the inability to do anything at all, can develop out of the requirement to always function. In addition to these general social phenomena, individual strokes of fate such as illness, unemployment, separation, and interpersonal conflicts can lead to the loss of inner balance. In the case of mental disorders arising from the above-described conflict between the individual and a world dominated by increasing economization, but also in specific mental illness, more and more creative recovery methods are used in addition to the classical forms of recovery in the sense of a creative coping with life.

As a truth seeker and naturopath, I have found that the most profound and beneficial lessons in life are taught by observing nature. What has taken me nearly two decades of research, learning, and education, I have learned in 2 minutes, from a seal. Why a seal you ask? A seal in nature is the perfect example of a mammal practicing the art of recovery.

In this book, our goal is to critically examine some of the ways in which recovery and recovery-oriented care are commonly viewed from the protagonist in their own care to the co-development and co-evaluation of programs. Read on to discover the four natural steps towards the art of recovery.

The Perfect Recovery Circuit!

So I have accepted the challenge/opportunity (depending on if you are into poison or medicine) to write in the fitness section of AZ Foothills Magazine each month. As you can see it's already the 2nd of July and my article is due the 5th (so I need to get to it!). As a post-rehab specialist I have learned over throughout the years the huge benefits you can get from doing the following healing modalities: cryotherapy, isokinetic resistance training, and infrared sauna. Each one of these therapies are extremely beneficial to the body, but I've discovered that by combining these 3 elements you get an awesome synergistic trifecta! The foundation for healing is anti-inflammation, thus doing things to your body (i.e. crazy cross-fit or acidic foods) to inflame it is not smart (muy malo). Life in general is pretty inflammatory, so if you find a program that helps "de-flame" the body you're on the right track. If you are interested in trying this circuit out contact me and I'll gladly take you through this "Recovery Circuit." Proof is in the pudding, if it is everything that I claim it to be than you have found your "Holy Grail" for recovery. Here's a brief break down of the benefits as you go through this amazing circuit:

Recovery Circuit Steps:

Step 1: Cryotherapy - Exposure to sub-zero temperature activates the central nervous system. The central nervous system (when activated) allows the release of beneficial hormones and enhances circulation. The hormones released produces a systemic response that provides pain relief, increased mobility, decreased inflammation, and mood elevation. 

Step 2: Recovery Warm-Up on the revolutionary CorePump® Machine - The CorePump® Machine provides isokinetic resistance, which is a safe, effective and efficient way to strengthen the entire body (without the inflammation typically associated with traditional exercise). You will also safely increase your flexibility as well as improve your cardiovascular/cardiopulmonary health.

Step 3: Infrared Sauna - The health benefits that you get from the infrared saunas are: Heart health and blood pressure, detoxification (eliminate toxic heavy metals), anti-aging, muscle growth, injury healing, weight loss, metabolic diseases, mood, mental health, cognitive function, inflammation, autoimmunity, and skin health. 

I could write a book on the benefits of these modalities because they are so numerous.

If you are interested in learning more about these benefits email me and I'll send you more information. 


What Is Involved In The First Hour?

Younger Tomorrow: The First Hour involves the following elements: cryotherapy, isokinetic training, infrared sauna, meditation and nutrients that help make the body alkaline. 

Here is a high level list of some of the basic benefits from each (we'll dive deeper into each topic in later blogs). 


  • Pain relief and muscle healing. ...
  • Weight Loss. ...
  • Reduced inflammation. ...
  • Preventing dementia. ...
  • Preventing and treating cancer. ...
  • Reducing anxiety and depression. ...
  • Improving symptoms of eczema. ...
  • Treating Migraine Headaches.

Isokinetic Resistance Training:

Isokinetic exercise is a type of strength training. It uses specialized exercise machines that produce a constant speed no matter how much effort you expend. These machines control the pace of an exercise by fluctuating resistance throughout your range of motion. Your speed remains consistent despite how much force you exert.

You can adjust the target exercise speed and range of motion to suit your needs. Different attachments on the machines can isolate and target specific muscle groups. You can use Isokinetic exercise to test and improve your muscular strength and endurance.

Infrared Sauna:

  • Detoxification. Sweating is one of the body's most natural ways to eliminate toxins, making it a crucial part of detoxification. ...
  • Relaxation. ...
  • Pain Relief. ...
  • Weight Loss. ...
  • Improved Circulation. ...
  • Skin Purification.


  • Meditation reduces stress.
  • It improves concentration. “I'm more centered and focused in everything I do. ...
  • It encourages a healthy lifestyle.
  • The practice increases self-awareness. ...
  • It increases happiness.
  • Meditation increases acceptance. ...
  • It slows aging.
  • The practice benefits cardiovascular and immune health.

Alkaline Diet:

Disease thrives in an acidic environment and dies in an alkaline diet. I like to keep things super simple. If a food class (ie animal products) produces acid, then it will cause inflammation in the body which is the distress call by the body that there is dis-ease occurring. For the most part I like to keep my diet strictly plant based, staying far away from animal products high in acidity (ie pork, red meat, fowl, dairy, etc...). Trust me there are so many foods out there that are quite delicious that grew from the ground (didn't have a mamma). 

I hope this high level view on my approach to the basics of The First Hour has been helpful and eye opening for you. 

Peace and Love

The 1st Hour. Purpose

My purpose for writing The 1st Hour came to me this morning while I woke up without my alarm (my phone died and I didn't want to go out to my car to get the charger) at 4am. I felt like I could have went back to bed, but I wanted to get to work on a ClickFunnels campaign that I am starting to build. As I laid in bed I realized that all of the "Greats" or "Success Stories" all seemed to have had the same habit first thing upon rising. Some go crazy like "making your bed" or "meditate" for an insane amount of time. I'm on the same page as Tim Ferriss regarding making the most out of each second of each day. I don't like to divide my days into seconds, minutes, or hours anymore. When I do I seem to watch my days fly into weeks, months, years and then holy shit, decades! No I've decided upon rising this morning to divide my time into moments. If I could recreate the calendar it would be a calendar of moments. That way life isn't about the number of days you survived on this rock, but the number of moments you've experienced. Makes sense right? Who cares if you're 199 years old with only 29 moments, I'd rather be 29 years old with 199 moments. 

Anyways back to the "purpose" at hand, The 1st Hour. 



Backed by 20 years of research and development, Hydra-Fitness Industries offers the safest and most effective exercise/rehabilitation equipment on the market today.

These unique machines, with their patented hydraulic system, work on many different levels to meet widely varying needs such as strength, power, endurance, cardiovascular conditioning, aerobic and anaerobic training, rehabilitation and cardiopulmonary activity.

Muscle contractions

In order to appreciate the nature of hydraulic resistance exercise with Hydra Fitness equipment, a brief discussion of the various types or classifications of muscle contraction is in order.

An isometric contraction occurs when the muscle develops tension but does

not change length. No movement occurs because the resistance is greater than the force potential of the muscle. A sub-maximal isometric contraction is termed a "static" contraction.

An isotonic contraction occurs when the resistance or load remains the same

and there is movement involved. That is, the force developed by the muscle overcomes the inertia of the resistance. In an isotonic contraction the velocity of the movement is not necessarily controlled, but rather the main classification characteristic is the constant load.

An isokinetic contraction is defined as occurring at a fixed velocity. In

practice this refers to a constant velocity of movement in a body part or segment rather than a fixed speed of shortening within the muscle.

Functional isokinetics provides all the accommodations or variable resistance of isokinetic training, but with variable speed and maximum overload at every joint angle throughout any range ofmotion.

Most isokinetic devices provide variable or accommodating resistance, which implies that the resistance is maximized according to the ability of the muscle to generate tension. The ability to generate tension is affected by the mechanical properties inherent in the lever system comprised of muscle and bone. In other words, there are "strong" and "weak" points in the normal range of motion which are usually referenced to the angle between the body segment(s) and the involvedjoint(s).




In an isotonic contraction, the greatest weight that can be moved through a normal range of motion is limited by what can be moved at the weakest joint angle. Therefore, the muscle is provided with maximal overload at that point only. There are usually ranges of strong and weak joint angles, but the degree of overload at the strongest joint angle is dramatically restricted if the movement is performed through the full range of movement. An alternative is to work with heavier resistance through a restricted range of stronger joint angles, which is effective, but time-consuming.

The major advantage of a system which provides accommodating resistance is that the muscle is able to generate more external force and the system provides more resistance. Many scientists and fitness professionals feel that such loading systems are superior to traditional isotonic or constant-load systems. Hydra-Fitness uses "functional isokinetics." This comprises all theadvantages of "isokinetics," but with "variable speeds" instead of non-functional fixed speeds.

Strength, power and velocity
Strength is often defined as the maximal tension genera ted by a muscle. Functionally, a

maximal isometric con traction at the strongest joint angle results in the greatest force.

Power is often defined as work accomplished relative to the time required to perform it. Since work is the product of force times distance, and work divided by time is power, the speed of movement can dramatically influence the power output of muscle. If a muscle can be trained for both force and speed, performance can be maximized. 'Performing at both high resistance and high speed is critical for peak performance of some athletes. Since high-velocity training with conventional weight-based systems is neither practical nor safe, hydraulic resistance systems have a great advantage due to their ability to accommodate both resistance and velocity safely.

The "specificity of training" principle

Specificity is one of the most important underlying principles governing the success of

While exercise scientists do not yet fully appreciate the nature of this

principle, it appears that maximal benefits occur when training is specific to the performance. Very simply, strength training tends to enhance strength, and aerobic training enhances endurance. But the issue becomes very complicated when athletes are preparing for competition. Sport specific training is not always possible (e.g. rowing in the winter) or desirable (constant training in one mode may cause boredom or · decrease motivation); therefore, alternatives are very important. However, in order to "transfer" as much of the training effect as possible to the actualperformance, the specificity principle must be adhered to.

Training with hydraulic resistance allows movement patterns and movement velocities nearer

to the actual performance. thereby enhancing the specificity effect.

Cardiorespiratory fitness

Circuit training with variable resistance hydraulic equipment is becoming increasingly popular. It involves a cardiovascular response that results in improved aerobic fitness. By using a variety of work-to-rest ratios in a circuit mode, both anaerobic and aerobic energy systems can be stressed. Circuit training with the variable resistance Hydra-Fitness systems at a high cardiorespiratory involvement can induce positive aerobic power training effects. When conducted at relatively high velocities with a work-to-rest ratio, the cardiovascular system will be stressed. This effect on the cardiovascular system has not been observed with circuit training on other strength -training equipment.

Traditionally, strength training exercises have not been utilized for cardiac rehabilitation because they were believed to represent increased risk for the patient. However, more recent studies have demonstrated the relative safetyof weight-carrying and circuit weight training exercises among cardiac patients who were only three months post-clinical. The addition of Hydra Fitness circuit training to medically supervised cardiac exercise programs mayenhance the patients' ability to meet many of the physical demands associated with their daily activities.

In summary, Hydra-Fitness resistance training systems uniquely provide the opportunity to exercise with accommodating resistance over a wide range of movement velocities. Most Hydra-Fitness systems offer alternating resistance and the choice of unilateral or bilateral movements. The equipment is well suited to circuit training and appears to provide excellent strength training gains from short-term programs.

Clearly, any training program is dictated by the need and the initial fitness level of the individual. The Hydra-Fitness line of resistance exercise systems can be adapted safely and effectively, regardless of the training objectives.

Fitness among the aging population

An often observed and reported trend among the elderly is loss of muscle, gain in fat and decline in overall body composition -- a condition that is not necessarily normal, but rather may be a result of lack of the proper type of exercise. Any exercise can significantly increase muscle mass and decrease

body fat content; however, conventional exercise equipment is not readily accepted by the aging. It is often viewed as intimidating and unsafe. Hydra Fitness equipment has been the single

alternative for fitness among the aging population due to its accommodating resistance, allowing

anyone at any age to begin exercising at their own level of fitness.

Evaluation of acute cardiorespiratory responses to hydraulic resistance exercise


F.I. KATCH, P.S. FREEDSON, and C.A. JONES. Evaluation of acute cardiorespiratory responses to hydraulic resistance exercise. Med. Sci. Sports Exerc., Vol. 17, No. 1, pp. 168-173, 1985. Accurate evaluation of the acute responses to resistance exercise training depends on the stability of the criterion measures. This is particularly true for maximal effort exercise where continuous "all-out" effort for each repetition is encouraged. The present study evaluated reliability of repetition number (repN), respiratory gas parameters (VO2, VCO2, VE), and heart rate (HR) for shoulder (SE), chest (CE), and leg (LE) exercise performed maximally on a single- unit, 3-station hydraulic resistance exercise machine (Hydra-Fitness, Belton, TX). On 2 separate days, 20 college men completed three 20-s bouts of SE, CE, and LE with a 20-s rest between bouts and 5 min between exercise modes. There were no significant differences between bouts or test days for repN, gas measures, or HR. Subjects performed 17, 19, and 21 reps during SE, LE, and CE. VO2 was 1.7 1.min-1 (24.3 for SE, 1.87 min-1 (25.5 .min-1) for CE, and 2.1 1.min-1 (28.6 ml .kg-1 min-1) for LE. These values, averaged, represented 52.8% of the max Vol determined on a continuous cycle ergometer test. The corresponding HR's during hydraulic exercise averaged 84.6% of HR max. Test-retest reliability coefficients ranged from r= .67 to .87 for repN, r = .41 to .83 for gas measures, and r = .72

to .89 for HR. The MET level averaged 7.5 (heavy), and caloric expenditure per minute averaged 35% higher compared with literature values for free weights and 29.4 and 11.5% greater than circuit exercise on Nautilus or Universal Gym equipment, respectively. It is concluded that there are reliable individual differences in repN, respiratory gas parameters, and HR during maximal effort exercise of relatively short duration performed on a multiple- station hydraulic resistance exercise apparatus.


Circuit weight training improves muscular strength and cardiovascular fitness (4-7, 18). The duration of a single circuit usually varies between 7 and 12 min for a 10-station routine, depending on the rest interval between exercises (15-60 s) and the number of repetitions performed per exercise (6-15 reps). Research with circuit weight training includes conventional free weights and barbells (8, 10, 17), stacks of weight plates that permit variable resistance exercise (4, 6, 7, 16), and cam and pulley devices that emphasize multiple

repetitions consisting of both concentric and eccentric muscle contractions performed to "momentary muscular failure" (9,11).

Recently, exercise machines have been developed that incorporate hydraulic cylinders to provide both variable speed and variable resistance (Hydra-Fitness Industries, Belton, TX). An important design feature of this equipment permits concentric-only maximal-effort exercise for the agonist and antagonist muscle groups during each repetition of a particular movement. When the machines are placed in typical circuit fashion, this type of resistance training is similar in function to traditional circuit weight training (3, 6). In conventional circuit training, the weight overload is usually set at 40-70% of maximum lift capability. For hydraulic resistance exercise, the individual attempts to exert maximum muscular force against a level arm throughout the complete range of motion in both directions of the movement. The nature of such "all-out" repetitive contractions during a given bout of exercise should significantly augment heart rate and metabolic response.

The present study is the first to evaluate individual differences in acute heart rate responses and measures of gas exchange for a 3-station, hydraulic resistive exercise machine. Because the magnitude of the heart rate and metabolic response depends to a large extent on exercise intensity, the reproducibility of maximum repetition number was determined during multiple bouts of chest, shoulder, and leg exercise. In addition, we have compared the absolute and relative energy expenditure of the hydraulic exercises with published data on other forms of resistance exercise.


Subjects. Table 1 presents the descriptive characteristics for the 20 male subjects. They were college students at the University of Massachusetts, Amherst, with no prior experience in a supervised program of weight training or weight lifting. Subjects received medical clearance from the University Health Services and signed an informed consent document in accord with University Human Subjects Review Guidelines.

Figure 1 – Subject performing chest exercise on the single-unit, 3-station hydraulic exercise apparatus.

Test apparatus. Figure 1 illustrates the exercise apparatus. On this device, there are three hydraulic cylinders; each is attached to its own layer system that provides concentric reciprocal movement primarily for the arms (chest press-chest row), arms and shoulders (shoulder press-lat pull), and legs (quadriceps extension-hamstring flexion).

Description of exercises. One of the experimenters demonstrated proper form and technique for each exercise according to guidelines specified by the manufacturer. The seat belt attachment on the machine was fastened around the waist to minimize extraneous movements. Resistance to movement can be regulated by selecting one of six speed settings from a dial on the machine. These settings correspond to six orifice sizes through which hydraulic fluid passes. The diameters of the orifices vary from 0.076 mm (setting 1) to 0.031 mm (setting 6). The dial setting for each exercise in the present study was 3 (0.076 mm orifice for CE and SE and 0.062 mm for LE). The exercises were performed as follows:

Chest exercise (CE). At the start of CE, the handles of the lever arm are held as close as possible to the axillary region just in front of the chest. The back and head remain in contact with the machine's upper body support. The handles are then moved forward as rapidly and forcefully as possible until a full extension position is achieved; the arms are then moved back to the starting position in similar fashion during the flexion phase of the movement.

Shoulder exercise (SE). At the start of SE, the handles of the lever arm are held at shoulder height. The arms are then thrust forcibly upward to full extension and then pulled down with maximal force to the starting position. The head and back are kept in contact with the upper body support.

Leg exercise (LE). At the start of LE, the arms hang vertically and grasp the underside of the bench to help secure the body to the machine. The head and back remain in contact with the upper body support. The ankles of both legs fit between ankle pads, with care taken to position the middle of the knee in line with the pivot of the lever arm. To initiate movement, both legs are fully extended with maximum effort from an initial angular position at the knee of approximately 90° and then flexed with maximum effort back to the starting position.

Each subject performed the maximum number of repetitions possible within a 20-s time interval. To count as one complete repetition, the exercise had to be performed as specified in the instructions. Repetitions were determined by visual observation for all exercises. During SE, a microswitch attached to the lever arm verified the visual count. There were never any discrepancies between the visual and microswitch counts.

Sequence of testing. Subjects were tested on four different days; days 1 and 2 were for assessment of body composition and max VO2, respectively. On the remaining two days, subjects performed three bouts of CE, SE, or LE, with the sequence of performing exercises on the first day balanced across subjects. Body weight was measured on each, day prior to testing. During the final 2 min of a 12-min rest period on the exercise apparatus, heart rate (HR) and gas exchange measurements (VO2, VCO2, VE) were obtained. Subjects then performed

a given bout of exercise for 20 s followed by a 20-s rest interval. This sequence of 20 s exercise, 20 s rest was repeated three times for each of the exercise stations. There was a 5- min rest (no exercise) until the next series of three exercise-bouts was performed. Subjects were instructed to perform maximally ("all out") for each repetition on all exercises. Strong verbal encouragement was given to exhort sub-jects to exert maximum muscular effort on each repetition.

Max VO2 test. Max VO2 was assessed on a Monark cycle ergometer. Pedalling rate was 60 rpm paced by a calibrated auditory-visual metronome; pedal rpms were counted electronically from a microswitch mounted on the pedal crank. Initial resistance was 1 kp for the first 2 min and 2 kp for the next 2 min. Thereafter, it was increased by 0.5 kp for each succeeding 3-min interval until subjects would no longer continue. This protocol is essentially the same as that described in a prior report (13). To compute max VO2, a plot was made of VO2 in relation to the actual work performed. The highest of two successive pairs of VO2 scores were averaged and designated max VO2. For all subjects, this occurred within the last 3 min of the test, even though pedal rpm and, thus, work rate usually declined during the last minute or two of performance.

Gas-exchange measurements. Metabolic measurements were determined by open circuit spirometry with an aliquot bag system for collection of expired air. Subjects breathed through a Rudolph high-velocity, low-resistance valve. Gas samples were collected for 40 s during each exercise/rest bout and expressed on a per-min basis. Expired air was also sampled during minute 5 of the 5-min rest interval between bouts. Expired gas volume was measured electronically as it passed through a turbine transducer into a mixing chamber. The flow transducer generated electronic pulses that were counted and displayed on a digital readout. The transducer was calibrated manually by forcing successive 3-1 aliquots through it from a calibrated 3-1 syringe at both steady (slow) and pulsatile (fast) flow rates that ranged from 3 to 70 1 for 30-s intervals. A 120-1 Tissot gasometer was used as the criterion measure to calibrate the transducer by having expired air pass in series from the Tissot through the transducer while a subject ran on a treadmill for 1-h periods at 0° grade and at different incline levels.

For gas analysis, the fractional concentration of the expired air samples were analyzed for 02 and CO2 by use of Applied Electrochemistry O2 and CO2 analyzers. Both analyzers were calibrated before and following each test with commercially prepared gas mixtures verified by the micro-Scholander technique. Energy expenditure was calculated for each interval as

kcal .min-1 = VO2 (1 .min-1) x caloric equivalent per 1 O2 at the given R (14). For R-values that exceeded 1.0, the caloric equivalent per 1 oxygen at an R of 1.0 was used.

Heart rate (HR; beats .min-1). A standard three-lead ECG and strip chart recorder were used to monitor HR continuously during all bouts of hydraulic exercise and the max VO2 test. For the analysis, HR was calculated from the last 6 beats of each 20-s bout of hydraulic exercise and the last 5 s of each minute during the max VO2 test.


Reliability of repetition number (repN)

To examine the metabolic and cardiovascular response of the three resistive exercises where work time during the performance was held constant, the stability of individual differences was determined for the number of repetitions performed for each exercise. Table 2 shows that the between-day reliability for repN, averaged across bouts for each exercise, was r = 0.76 for

LE, r = 0.87 for CE, and r = 0.89 for SE. There were no significant differences between days for corresponding bouts of each exercise (P > 0.05). However, repN performed for each exercise (using the average of test and retest), declined slightly across bouts 1 to 3; 1.1 reps (5.7%) during LE, 2.4 reps (11 %) during CE, and 2.5 reps (13.9%) during SE.

Reliability of gas exchange measures and heart rate

Oxygen uptake (VO2, 1. min-1. The results in Table 3 illustrate that reliability for VO2 ranged from r = 0.41 to 0.69 for individual bouts across exercises. For each exercise, the average reliability across bouts was r 0.52 for LE and r = 0.58 for CE and SE.

A repeated measures ANOVA (days x bouts x exercise) revealed that for each exercise, there were significant increases in VO2 between successive bouts of each exercise (F = 216.9; P < 0.05). For the exercise x bout interaction (F = 5.49; P < 0.05), a Tukey post-hoc multiple range test showed that VO2 LE and CE (bout 1) were not significantly different. All other between exercise comparisons of VO2 for all bouts and exercises were significantly different at P < 0.05. In most cases, LE elicited the highest VO2 response followed by CE and SE.

Heart rate (beats/min). The reliability coefficients for HR averaged across bouts was r = 0.80 for legs and r = 0.79 for chest and shoulders. With the exception of chest exercise, reliability and, hence, individual differences increased from bout 1 to bout 3 as a function of increasing heart rate. The results of the repeated measures ANOVA showed that the differences in HR between successive exercise bouts were significant for all exercises (P < 0.05). The magnitude of the increase in HR from bout 1 to 3 was fairly similar; 12.9 bpm (9.0%) for legs, 10.7 bpm (7.4%) for chest, and 13.2 bpm (9.5%) for shoulders. There were no significant differences in HR between corresponding bouts of the three exercises (exercise x bout interaction; F = 0.34). Reliability was higher for HR on each exercise (averaged across bouts) compared to the measures of gas exchange.


In this experiment, individuals were asked to perform maximally at one of 6 pre-set resistance settings throughout the range of movement for each repetition. However, there was no way to quantify the total amount of work or power accomplished. The external gauges mounted at eye level did provide immediate visual feedback of force exerted, but these gauges were not useful for quantitative assessment. Thus, any inconsistency in repN or exercise effort could produce low reliability for heart rate and metabolic response, as well as significant differences in the aboslute scores for these variables. In the present study, it was encouraging that reliability for repN ranged from r = 0.68 to r = 0.93, since fluctuation in maximal effort exercise could have markedly affected concomitant measures of heart rate and gas exchange.

For VO2, reliability coefficients ranged from r = 0.41 to r = 0.69; for heart rate, reliability ranged from r = 0.72 to r = 0.89. These results show that the acute VO2 and heart rate responses were consistently stable across days. These findings for VO2 are in contrast to data of Wilmore et al. (19), who reported that reliability for VO2 and kcal ranged from r = 0.20 to r=0.70. The low coefficients were ascribed to decreased interindividual differences in VO2 expressed relative to body weight, rather than unstable measurements during circuit exercise.

The peak VO2 measured during the three hydraulic exercises were 2.10, 1.87, and 1.78 1. min-1 for LE, CE, and SE, respectively. For comparison purposes with the data of others, oxygen consumption and heart rate were expressed relative to maximal values on the cycle ergometer test. For LE, V02 was 57.4%; for CE, it was 51.9%; and V02 for SE was 49.2%. Heart rate was highest during LE (85.4%), followed by heart rate during CE (85.2%) and SE (83.2%). Thus, it can be stated that subjects performed exercise at an average heart rate of 84.6% of HR max, at a corresponding average VO2 of 52.8% of the max VO2. McArdle and Foglia (12) reported that V02 ranged from 0.43 1. min-1 to 0.59 1.min-1 during one set of 8 reps for the 2- arm curl, arm and back press, and squat free weight and isometric exercises. Post-exercise VO2 was higher during the first minute of recovery (0.84 to 1.271 .min-1) compared to exercise. In terms of energy cost, the peak metabolic intensity was approximately 6

kcal .min-1. The highest heart rate occurred during the 2-arm press (134 beats/min or approximately 69% of maximum heart rate using an age-predicted maximum heart rate of 195). Byrd and Barton (2) reported that novice weight lifters had heart rates that averaged 145 beats/min after a 1-h workout, while the heart rate of experienced lifters averaged 152 beats/min.

Wilmore et al. (18) reported that 30 s of circuit exercise performed by men and women on Universal Gym equipment for three circuits of 10 exercises (performed at 40% of 1 RM) required 70% of max HR and 45% or less of max V02. For circuit exercise performed by five men at 7 stations using Cybex isokinetic equipment at slow speed (60°/s) and fast speed (120°/s) for 3 circuits, 12 reps/set and 30-s interval between sets, heart rate averaged 69% of max HR, and VO2, averaged throughout exercise, was 49% of max VO2 (3). Energy expenditure, computed in the same manner as in this study, averaged 9.6 and 9.9 kcal .min-1 for slow and fast speed circuits, respectively.

A recent study by Hempel and Wells (9) evaluated the energy expenditure of circuit exercise using Nautilus equipment. For the 16 male subjects, VO2 corresponded to 35.9% of max VO2, and heart rate averaged 71.7% of max heart rate.

Table 4 compares the pertinent data of the present study with results from the literature that have evaluated various forms of resistance exercise relative to heart rate and metabolic response. These comparisons show that the three exercises performed on the hydraulic equipment produce greater metabolic and heart rate responses than exercise performed isometrically and with free weights (12) or typical circuit exercise work-outs on Universal Gym (19) or Nautilus equipment (9, 11). This is true even when the average response based on the three exercises is used as the frame of comparison.

The caloric expenditure for the three hydraulic exercises averaged 37.7 Id (9.0 kcal .min-1); this is approximately 35% higher than exercise with free weights (12), 29.4% greater than the average kJ based on two studies using Nautilus (9, 11), and 11.5% higher kcal than circuit exercise with Universal equipment (19). The energy expenditure values in the present study averaged 8.9% less than slow and fast speed isokinetic circuit exercise (3). It seems reasonable that differences in kcal (and associated physiological measurements) between the present results and other studies of circuit exercise are due in part to methodological differences. We

have reported values associated with each bout of exercise (and the average) in contrast to an average value determined throughout circuit exercise.

Although the reliability of individual differences in work performance (reps) was only moderate, it was high enough to provide for consistency across days in the physiological response to maximal effort exercise. The use of on-line analog to digital devices interfaced with a microcomputer would provide two important advances with this type of equipment: (1) feedback to the user regarding effort (e.g., time to peak effort, average work and power, total work and power, and work and power expressed relative to range of motion), and (2) quantification for precise evaluation and comparison with other modalities of resistance exercise.

The results of the present study demonstrate that exercise performed on a 3-station hydraulic resistance apparatus produces reliable individual differences in repN, heart rate, and associated respiratory gas measurements. The magnitude of the average heart rate and metabolic response patterns with maximal effort hydraulic exercise is in the range recommended by the American College of Sports Medicine to promote improvements in cardiorespiratory fitness (1). When energy expenditure is expressed in the MET classification scheme for defining exercise intensity, the MET level averages approximately 7.5, which would be considered heavy intensity exercise.

A description of the Total Power apparatus is available from the manufacturers: Hydra-Fitness Industries, 2121 Industrial Park Road, Belton, TX 76513. This study was supported by a grant from Hydra-Fitness Industries to the Department of Exercise Science, University of Massachusetts, Amherst, MA.

The authors thank Maureen Rafflo for her technical assistance. Frank I. Katch and Patty S. Freedson are Fellows of the American College of Sports Medicine.

Present address for Carole A. Jones: Mt. Sinai Hospital, Hartford, CT.


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