This paper is a summary of our recommendations and positions regarding physical health-enhancing exercise. It is intended only as a reference.  As such, the rationale and support for our positions (i.e., scientific documentation and references) are intentionally withheld. Detailed position papers that include a thorough discussion and defense of these positions will be published shortly. (If you desire clarification or additional information prior to the release of these papers, please contact one of the NCES directors via telephone)

Why the need for resistance training a.k.a., strength training, weight training?

Unknown to most people, one of the most debilitating health problems that plagues each and every adult is the loss of skeletal muscle tissue. Each year, beginning from the point that physical growth and maturation ceases (approximately age 25), we lose approximately 1/2 to 1 pound of muscle. According to several noted experts in the field, physical activity does nothing to halt muscle loss – no matter how vigorous an activity may be (i.e., basketball, tennis, running, stair climbing, etc.). As muscles atrophy, many physical functions begin to weaken and decay (strength, endurance, stamina, bone density, metabolism, overall physical capacity). If we allow muscular atrophy to continue into our senior years, we can lose our independence. We will require care from others because we become too weak to care for ourselves. Only strength training can halt and reverse muscle loss. There are no drugs, no health foods, and no recreational activities that can help. Strengthening muscle also causes bone remodeling, enhances joint flexibility, increases the metabolism permanently and, in doing do, decreases risk of injury if involved in recreational activity. Strength training is absolutely essential to our long term health and maintenance of physical abilities.

Exercise Qualifiers

1) Demanding muscular work

The skeletal muscles are the means through which all trainable systems (including the cardiovascular/respiratory and skeletal systems), of the body can be exercised, and, therefore, stimulated to produce positive physiological adaptations. Muscular work must be of sufficient intensity to induce a level of fatigue (i.e. muscular inroad) that meets or exceeds the body¹s threshold for stimulation for such adaptations. For reasons explained later, each single exercise should be carried out to the point of momentary muscular failure. We define failure as that point in an exercise where concentric contraction ceases due to fatigue while continuing to attempt completion of the repetition. Failure should occur within no more than 3 minutes, and, ideally within 1 to 2 minutes.

2) Meaningful mechanical loading of the muscular structures

Muscular (metabolic) work of sufficient inroad to induce momentary muscular failure requires sufficient resistance opposed to the mechanical actions of those muscles being trained. This resistance ideally must occur over a significant portion of the possible range of motion of a given joint/muscle group.

3) Movement tracks muscle and joint function

For optimal stimulation of the muscular structures and the subsystems that serve it, muscles and joints should be worked throughout a full, pain free range of motion in a manner dictated by human anatomy and biomechanics. This is to say "function dictates design" (i.e., the exercises performed should be designed and performed in a manner consistent with the primary function of the muscles being trained and NOT according to some sport skill or action).

The Objective of Exercise

Exercise should stimulate positive physical adaptations within the musculoskeletal structures. These adaptations include five major goals:

1. Lean tissue improvement
2. Bone density enhancement
3. Increased cardiovascular/respiratory efficiency
4. Improved resistance to injury
5. Enhanced muscle/joint range of motion/function.

The Objective of Recreation

Recreation permits people to escape the daily grind through enjoyable activities. Jogging, swimming, gardening, biking, rollerblading, etc. are examples of popular physical activities. Though physical recreation is important to some individuals, it CANNOT replace the need for progressive resistance strength training. Care should be taken not to confuse recreational activities with exercise. Although many people perform recreational activities with the hope of attaining exercise related benefits, most such benefits are impossible to achieve through said recreational activities. Furthermore, attempting to turn recreation into exercise often leads to injury.

Generic Physical Activity vs. Planned, Structured Exercise:

Most of the major governmental and fitness industry institutions and organizations have released position statements regarding generic lifestyle related physical activities and their supposed health enhancing, life extending benefits. These organizations include the American College of Sports Medicine (ACSM), American Council on Exercise (ACE), International Federation of Sports Medicine (FIMS), Center for Disease Control (CDC), Office of the Surgeon General, and World Health Organization (WHO).

Most of these organizations have suggested that the accumulation of 30 minutes of daily, non-continuous, generic, physical activity can provide many of the same health and fitness benefits of structured exercise. Under this belief, acceptable activities include: walking, gardening, house cleaning, playing with the kids, taking the stairs instead of the elevator, grocery shopping, or any literally any other form of "movement". It is implied that those people who lack the time or desire to exercise regularly can, simply by being "active", improve their physical health.

The NCES strongly disagrees with the assertions made by these organizations, and suggest that their advice is tantamount to malpractice. The erroneous conclusions formed by these organizations arise from a violation of a cardinal principle of scientific research -- association vs. cause and effect. These organizations have made the assumption that because people who are physically active tend to be healthier, that therefore, the activity itself caused their good health. This is not necessarily true. It is just as likely that people who are healthy choose to be more active simply because they can. Their good health enables their active lifestyle.

At present, there is no scientific evidence that indicates a cause and effect relationship between generic activity and health. The NCES feels that it is irresponsible and unethical to teach people that there is. Generic physical activities do not meet the necessary threshold required to stimulate meaningful positive physiological adaptations. Furthermore, regardless of a person’s activity level, progressive resistance strength training remains a requirement for maintenance of optimal physical capacity.

NOTE -- The NCES is not suggesting that people stop being physically active. We merely point out that physical activity cannot cause positive tissue remodeling, nor replace the need for structured exercise.

Dose/Response: Exercise is a form of physical stress. When this stress (a dosage of exercise) is properly applied to the muscular structures, the metabolic work and resulting fatigue creates a stimulation from which the body overcompensates and improves (response). Muscle and bone growth are the primary responses. The smallest dose of exercise that produces the optimal response is ideal. A greater than necessary dose may not produce a better response and often produces side effects expressed as excess fatigue, atrophy, and injury.

Progressive Resistance: As the muscles become stronger, it is necessary to increase the resistance applied in order to force continued progress and positive adaptations. Fractional increments are necessary once an individual becomes more advanced and has neared his genetic limitations.

b) Exercise Program Details

It should be noted that regardless of the overall length of time to complete a repetition, if the start of each repetition is performed quickly or suddenly (firing out), or the repetition becomes segmented and non-uniform, the benefits of a slow cadence are nullified.

Exercise Form/Technique: Form and technique are dictated by anatomical function and proper equipment (machine) design, which should always track such function through a full range of muscle movement. Form must remain consistent throughout the set and across exercise sessions to assure proper muscular inroad (fatigue), and to allow for accurate interpretation of progression.

Exercise Selection: For maximal development of all muscle groups, a comprehensive selection of both compound movements (multiple joint exercises), and rotary movements (single joint, isolation movements) should be utilized. Each workout routine should be designed to address the major muscular structures with as little overlap of individual muscles as possible to avoid over-training them; it should accomplish this with as few exercises as possible, providing complete muscular development is not compromised. While all humans are essentially anatomically and physiologically the same, exercise selection should be consistent with any structural limitations displayed through previous injury, or trainee discomfort unrelated to the desirable demands of proper exercise.

In order to provide work for the greatest amount of muscle mass/body parts using the fewest exercises, compound movements should dominate a routine. However, since the structure and function of certain muscle groups require single joint rotary movements to train them adequately, these type exercises must also be included. Examples of such structures include the muscles of the cervical and lumbar spine, the "knee flexion" function of the hamstring muscles, the muscles of the forearms, and those of the calf.

Machines vs. Free Weights: Both free weights and machines can be used. However, certain muscle groups CANNOT be adequately addressed with freeweights thus, requiring machines. Properly designed machines are safer, and provide a more effective and efficient route to muscular stimulation. Therefore, we recommend the use of quality machines. The NCES provides a list of manufacturers who design such machines, (see below).

Program Development Suggestions: Novices can perform up to 8 -10 exercises. When a trainee reaches thorough inroad consistently, and as overall strength and exercise intensity increases, exercise volume should be reduced to 6 - 8 exercises, depending upon the number of compound and rotary movements employed. Without these changes over time, the intensity and accumulated inroad of an advanced trainee’s workouts become so great that the individual cannot withstand the exhaustive effects of the workout and recover/adapt before the next exercise session.

Note: A popular trend in recent years, especially among advocates and practitioners of High Intensity Training (HIT), SuperSlow^® , and Heavy Duty™, has been to employ very brief and short, so called "consolidation" routines, and workout very infrequently -- perhaps just once each 7 - 14 days.  A typical workout in this fashion, lasting just 10 - 15 minutes, may consist of only 3 or 4 exercises to work the entire body -- all compound movements.  Advocates of this type of training insist that anything more than this extreme brief and infrequent workout results in over-training and thus, lack of results/progress.

It is the position of the NCES that while consolidation routines can be effective at improving general strength and functional ability, this type of program is less than optimal for well rounded and complete development of all muscles groups, and is also insufficient for purposes of physique enhancement/body building.  Furthermore, there are concerns consolidation training is insufficient for optimal metabolic conditioning.

The NCES believes that there are several program variations and techniques that can be employed to prevent over-training and stimulate better gains in strength, conditioning, and physique development, without resorting to consolidation routines and/or extremely infrequent training.  Some of these variations include: split-bodypart routines which reduce systemic stress and allow better recovery; a sensible use of a combination of both rotary and compound exercises; avoidance of extreme inroading techniques that overstress the neurological system; and allowance of more rest/recovery between individual exercises/machines in a workout. 

In the near future, NCES will have available a detailed article discussing our experiences and findings relating to the above topic and the resulting modifications to our recommended training methodology.


Aerobics/Cardiovascular Training:

Properly applied, full-range of motion strength training optimizes muscle and joint flexibility and function. Stretching techniques, which stretch and lengthen tendons and muscles (simply for the reason of lengthening them) can be dangerous and introduce levels of joint laxity and muscle/tendon instability. Except for specific rehabilitative procedures, we do not recommend stretching programs, or activities and programs such as Pilates and Yoga. Unless an individual is practicing extreme activities such as certain martial arts, ballet, gymnastics or similar activities, there is no need to increase range of motion beyond that attainable by normal function. In short, muscular flexibility is a misnomer. Joints flex. Muscles contract and un-contract.

Exercise should not be performed so as to mimic sports actions. Such training compromises, and in many instances ignores, the basic fundamentals of proper exercise, human motor learning, skill acquisition and skill transfer. It also increases the probability of injury. Sports performance should be improved through separate and distinct skill practice. Strength training better prepares the muscular system for skill practice and makes it resistant to the injury risks such practice entails.

Plyometrics/Explosive Training

Plyometrics (bounding, jumping, box jumps, etc.), and explosive strength training protocols incorporate excessive levels of force which increases the injury potential by challenging the tensile limits of attached ligaments, tendons, and muscle. Plyometerics offer no benefits that proper strength training combined with skill practice do not provide. If one desires to remain health and injury free, quick, sudden movements against resistance should be avoided like the plague.

Orthopedic Physical Therapy

Passive modalities, such as hot/cold therapy, stretching, physio-balls, Swiss balls, fit balls, hot baths, and ultrasound treatments only treat symptoms (pain and swelling), much the same way aspirin does. They cannot stimulate tissue remodeling (strength, functional enhancement) and cannot meaningfully improve or cure chronic conditions. Orthopedic physical therapists place undue emphasis on these modalities. Properly applied resistance exercise is the only physical therapy that restores and enhances the physical function of injured structures. Physical therapists need to be educated and trained in its proper application.

Fat Loss Programs

Fat loss requires three main elements: a negative net energy balance (calorie deficit), a nutritionally complete, well-balanced daily diet, and strength training exercise. Without a calorie deficit, fat loss is impossible. Without a nutritionally complete diet, vitamin and mineral deficiencies may result. Without strength training, lean tissues, including muscles and bone, atrophy. This atrophy depresses the body’s metabolism causing fat accumulation. Adding aerobic activity for the purpose of fat loss is inefficient, increases risk of injury, and may compromise the preservation of lean tissues. Most authorities fail to point out to people the difference between calories burned during activity minus the calories burned at rest. Research and clinical evidence has shown that in the long run, fat loss is greater with strength training and diet alone, without aerobics.

Exercise Equipment Recommendations

Presently, most exercise equipment companies do not understand exercise equipment design principles, and consequently violate many of them. Machines should be designed to properly track muscle and joint function and provide a variable source of resistance that mimics the unique strength curve of each muscle. Machine seat positions and other settings should be adjustable to enable use by a diverse clientele. Safety must never be compromised to facilitate slick design, though it often is.

Companies sometimes produce several acceptable machines, but their overall line remains unsatisfactory. A few companies excel in equipment design and produce superior products. The best of these is MedX^®. Vintage Nautilus^® machines (not the newer models), are bio-mechanically sound, and if retrofitted with friction reducing components and redesigned cams, rival several MedX pieces. Several Hammer Strength^® pieces suffice, however, many Hammer Strength machines remain inappropriate.