Sports Fitness Training

While starting a resistance exercise program, remember to consider your age, fnness level, and the personal goals you would like to achieve. Strength training exercises are done in a set, or a single series of multiple repetitions using the same resistance. Current research tells us that for healthy people of all ages(and for many individuals with chronic illnesses), single set resistance programs of up to 15 repetitions per exercise, performed a minimum of two days per week, are recommended. Each of your workout sessions should include 8 to 10 different resistance exercises that involve the major muscle groups of the upper and lower extremities and the trunk. Somewhat surprisingly, single-set resistance programs have been recently recommended by the American College of Sports Medicine 47 for the majority of the United States population because they produce most of the health and fitness benefits associated with much more time consuming, traditional multiple-set programs(e.g., 3 sets of 10 repetitions of each exercise three days per week).

Remember that resistance training exercises cause microscopic damage(tears) to muscle fibers, and the rebuilding process that increases the size and capacity of the muscle takes about 2.4 to 48 hours. Thus resistance training exercise programs should include at least one day of rest and recovery between workouts before overloading the same muscles again.

Resistance Training Program Guidelines

• Resistance training should be an integral part of an adult fitness program and of sufficient intensity to enhance strength, muscular endurance, and maintain fat-free mass(FFM).

• Resistance training should be progressive in nature, individualized, and provide a stimulus(overload) to all major muscle groups in the body

• One set of 8 to 10 different resistance exercises that condition the major muscle groups 2. to 3 days per week is recommended.

• Most healthy individuals should complete one set of 8 to 12 repetitions for each selected exercise; for older(50 to 60 years of age and above) and more frail persons, one set of 10 to 15 repetitions may be more appropriate.

• The goal of this type of resistance training program is to develop and maintain a significant amount of muscle mass, endurance, and strength to contribute to overall fitness and health throughout the life span.

• If sufficient time is available, multiple-set resistance exercise regimens using heavier weights and fewer repetitions will result in greater strength gains and fitness benefits.

Ballistic stretching Techniques that employ the repetitive, rapid stretching of muscles with no holding or the stretch at a terminal position; not recommended because of the risk of injury to muscle and/or tendon

Muscular strength The amount of force that a muscle is capable of exerting.

One repetition maximum(1 RM) The amount of weight/resistance that can be lifted/moved one time, but not twice; a common measure of strength.

Muscular endurance A muscle’s ability to exert force repeatedly without fatiguing

Resistance exercise program A regular program of exercises designed to improve muscular strength and endurance in the major muscle groups.

Hypertrophy Increased size(girth) of a muscle.

What Do You Think?

What types of resistance equipment can you currently access? Based on what you’ve read, what specific actions can you take to increase your muscular strength? Muscular endurance? How would you measure your improvement?

Although we have been exhorted to exercise for much of the twentieth century, researchers and scientists continue to examine the world of fitness and exercise to determine the true impact of too much exercise, too little exercise, and the wrong and right types of exercise. Two recent studies cast an interesting light on exercise benefits for individual health.

The first, a study of 2,428 adults over a six-year period, examined the risks that those of us who are out of shape face when we suddenly decide to don exercise clothes, lace up the shoes, and hit the exercise trail. The research team studied heart-rate changes in the first minute after exercise among patients who had previous symptoms of heart disease. They found that people whose hearts took longer to slow down, or recover, after exercise were nearly four times more likely to die during the six­year study period than were participants with normal recovery times. While just 26 percent of all people in the study had abnormal recovery times, these people constituted 56 percent of all deaths during the course of the study. In addition, the study indicated that people who demonstrated good heart­rate recovery are more likely to benefit from heart surgery and other corrective procedures in the event of cardiovascular problems.

Results of the study indicate that people who have high blood pressure, are obese, take heart medications, and are out of condition physically face significant risks of heart failure when they begin unsupervised, strenuous physical activity. For someone out of shape, getting back into shape should be viewed as a serious behavioral change. Efforts to lose weight, reduce blood pressure, and work up to high-energy expenditures should be done gradually and under a doctor’s supervision. Although this has long been the recommended plan of action, this study confirmed the importance of following that plan. Most important, however, the study helped identify heart-rate recovery as a significant indicator of benefits and risks.

The second of the landmark studies was an epidemiological study of the exercise behavior patterns of over 14,000 female participants in the Nurses’ Health Study Although physical activity has long been associated with the reduced risk of coronary heart disease, little has been known about the benefits of certain types of exercise, particularly for women. Walking, in particular, has long been believed to be highly beneficial and often has been recommended as part of a rehabilitation program for people recovering [rom heart problems and other serious illnesses, but questions still arose about its specific benefits. Until the Nurses’ Health Study, the role of walking in the battle against heart disease had not been carefully analyzed, despite being the most common form of exercise among women.

In the Nurses’ Health Study, women’s risk factors and exercise behaviors were assessed every two years for a period of 14 years. Results of the study provide compelling evidence of the benefits of walking. It indicated that brisk walking may, in fact, be just as beneficial for the reduction of cardiovascular disease as vigorous exercise. Results suggested that a regimen of brisk walking for a total of three or more hours per week(an average of 30 minutes per day) could reduce the risk of coronary events by 30 percent to 40 percent. Increasing this time provided even greater benefits. This is in line with the most recent recommendations from the Centers for Disease Control and Prevention, the American Col1ege of Sports Medicine, and the Surgeon General’s Report on Physical Activity and Health.

The implications are clear. What we have long suspected is true: Walking makes good sense! It is relatively available to everyone, requires no special equipment, can be done alone or in groups, and may be less damaging to joints over time than repetitive running or other strenuous activities. So put on those walking shoes, and let’s get going.

Under normal physiological conditions, cells are highly efficient at maintaining steady state. However, under conditions of physiological stress, such as hypoxia (reduced oxygen supply) caused by ischemia or strenuous exercise, the energy balance can be disrupted and the functional integrity of the cell can be compromised. In these conditions, ATP concentrations fall, which leads to increases in ADP and AMP levels. In an attempt to maintain energy balance the first response of both heart and skeletal muscle cells is to break down AMP, leading to an increase in cellular IMP concentration. If ATP use continues to exceed the rate of regeneration, energy charge is further depressed. The ultimate result is catabolism of IMP to inosine and then hypoxanthine, and AMP to adenine. Hypoxanthine and adenine are lost from the cell and the concentration of total adenine nucleotides is depressed. As such, a fall in energy charge below physiological limits of the cell is prevented and it takes several days for the concentration of adenine nucleotides to return to normal.

How Women Respond to Exercise

Despite the popularity of strength training and flexibility among women in recent years, there has been little scientific study of specifically how women respond to this type of exercise. With endurance exercise, some data suggest that women use less protein for energy than men perhaps as a result of differences in fat use induced by gender-specific hormonal responses. Rodent data indicate that estradiol is protective for muscle cell membranes and, consequently, part of this response may be due to less exercise­induced damage to the muscle membrane in women. Moreover, there is some evidence that protein need with endurance exercise may even vary across the menstrual cycle Unfortunately, the effects of strength training on protein requirements in females have not been investigated extensively. Based on the observed gender differences in metabolism and the known differences in hormonal responses, it is quite possible that women respond to strength exercise somewhat differently than men. As a result, detailed study of how strength exercise training is influenced by dietary protein in women is needed.

Static Exercise

Isometric contractions are usually held for 6 to 10 seconds and require a minimum exertion of two thirds maximum force. Maximum exertions produce greater results than sub-maximum efforts. A total contraction time of 30 seconds of applied force is desirable. This can be achieved by two or three confections of long duration or more contractions of shorter duration for each muscle exercised.

Isometric exercises are effective for developing strength, but this approach has some important limiations. The most serious of these is a higher than expected rise in exercise arterial blood pressure and an increased workload on the heart throughout the entire contraction. All-out straining isometric contractions should not be performed by individuals with heart and vascular disease. A second limitation is that strength developed isometrically is joint­angle specific. Maximum strength development occurs at the angle of contraction, with a training carryover of approximately 20 degrees in either direction from that angle. To develop strength throughout the muscle’s range of motion, you must perform isometric contractions at several different points in the range of motion.

Because muscles cannot overcome the resistance in isometric training, measuring improvement is difficult, constituting another limitation of this system. Improvements in strength can be measured if exercisers have access to specialized equipment, such as dynamometers and tensiometers, that record the amount of force applied. Motivation for exercise is difficult to sustain without feedback.

Research indicates that isometric exercise systems are as effective as dynamic exercise systems for developing strength. The question is not which system is better but which system best satisfies the intended use for the newly acquired strength. The transferability of strength to occupational and leisure pursuits is very relevant.

Strength developed in the muscles is highly specific to the manner in which the muscles are trained .muscles trained isometrically perform best when stressed isometrically; muscles trained dynamically perform best when stressed dynamically. There is some transfer of isometric training to everyday life. Carrying groceries, a baby, or any object in a fixed position or pushing and pulling objects requires isometric strength, but most movements are dynamic, md transfer is more widely applicable from dynamic systems of training.

Dynamic Exercise

Dynamic exercises include isotonic (equal tension), variable resistance, free weights, and isokinetic (equal speed).

Isotonic Training

Isotonic exercise training systems use both concentric and eccentric contractions as the exercising muscle shortens and lengthens about a joint. Both types of contractions contribute to the development of strength.

Variable Resistance Training

Variable resistance exercise equipment was developed in response to isotonic exercises not maximally stressing muscles throughout their full range of motion. The maximum weight lifted isotonically is limited to the weakest point in the musculoskeletal leverage system. The weight appears lighter at some points in the joint movement and heavier at others. In reality, the weight itself is constant and the human bony leverage system changes.

Free-Weight Training

Isotonic training with free weights (dumbbells and barbells) continues to be an appropriate method for strength development. Free-weight training provides many advantages. For athletes, it yields some flexibility in strength development because the movements are not confined to a track. Exercises can be selected or improvised to simulate the movements required by specific sports, allowing the development of the muscles that will be used in competition. Concurrently, ancillary musculature that plays a supporting or stabilizing role for the major muscles is also stimulated and developed.

Circuit Resistance Training

Circuit resistance training (CRT) is very effective for individuals who wish to develop several fitness dimensions simultaneously. Muscular strength and endurance, changes in body composition, and improvement in cardiorespiratory endurance can be attained together.

Exercise Intensity

Several early studies indicated that at least with aerobic ­type exercise, the contribution of amino acids to exercise energy production was linearly related to exercise intensity. The branched-chain amino acids (leucine, isoleucine, and valine) are the major ones oxidized and the mechanism responsible is thought to be an exercise intensity-dependent activation of the limiting enzyme (branched-chain oxoacid dehydrogenase activity) in their oxidation pathway.

Exercise Type

Apparently any increased protein need for strength exercise does not involve this exercise intensity mechanism because, despite the intense nature of this type of exercise, amino acid oxidation remains unchanged . Likely, this is a result of the large anaerobic component of strength exercise. Consequently, if body­builders need large amounts of protein it is not to provide auxiliary exercise fuel (carbohydrate provides that) but rather because sufficient amino acids must be available to maximize any increase in muscle synthetic rate produced by the exercise stimulus. Several studies indicate that there may be some truth to this commonly held beliet However, the optimal intake would appear to be 1.5-2.0 g/kg/day. This is an amount far less than what many strength athletes consume on a regular basis. Several possibilities might explain this apparent contradiction. Obviously, the athletes could be incorrect, i.e., they may have been influenced by a powerful placebo effect.

Alternatively, some other constituent in high-protein foods might, in combination with the surplus supply of amino acids, be responsible for a muscle-building effect. Several candidates are possible including creatine, a nitrogen compound found in meat and fish that has been studied recently, Although not all studies report positive effects with creatine supplementation, many demonstrate significant ergogenic effects (10% or more), especially during intense brief efforts. Such exercise-enhancing effects combined with a training program might accelerate further the normal gains observed with strength training indirectly via a super training effect. Moreover, some data exist indicating that creatine has anabolic effects on muscle, which could also playa role. Finally, although associated with a variety of adverse health effects, some compounds (i.e., anabolic steroids) are known to be anabolic 46 and it is possible that the high-protein intakes consumed by some strength athletes are only advantageous when combined with these agents.

Exercise Duration

With exercise duration, energy use from amino acids increases likely due to the decreased availability of carbohydrate as the body’s stores of this important fuel can be depleted in a single exercise bout. A similar response occurs with starvation, i.e., protein can be used for energy once the limited carbohydrate stores are exhausted. This may play some role for strength athletes if training sessions are prolonged.

Training History

In endurance exercise training, it appears that amino acid oxidation both at rest and during exercise increases perhaps due to training-induced changes in branched ­chain oxoacid dehydrogenase activity. Yet, this possibility remains controversial as the data from one study disagree and no obvious explanation to explain the discrepancy is available. The data with strength training are also somewhat unclear. It has been suggested that protein needs of novice bodybuilders might exceed those of more experienced strength trainers. Although this is consistent with the well-known observation of greater gains in muscle growth of novice strength trainers, several other studies indicate protein needs remain at similar levels for more experienced strength athletes. A recent study with acute eccentric exercise demonstrated similar increases in protein synthesis between resistance-trained and untrained subjects but that protein breakdown was greater in the latter This observation may explain why prior eccentric exercise reduces subsequent muscle damage and pain, and because eccentric exercise is part of most training programs this may indicate that the magnitude of increased protein needs induced by strength training could be reduced as one becomes more experienced. However, at this point in time, this question cannot be answered conclusively. More study of the protein needs of novice versus experienced strength trainers is definitely needed.