International SportMed Journal - Volume 2, Issue 3, 2001
Volume 2, Issue 3, 2001
Author Sheila R. TaylorSource: International SportMed Journal 2, pp 1 –10 (2001)More Less
Conventional sleep theories and popular opinion support the concept that exercise improves sleep. Despite equivocal empirical findings, the American Sleep Disorders Association includes exercise as a nonpharmacological component of sleep hygiene. Exercise should be aerobic, moderate to high intensity, last at least 30 minutes (longer in trained subjects), and be conducted 3-6 hours before bedtime if it is to improve sleep by decreasing sleep disruptions, shortening time to fall asleep, and increasing slow-wave sleep. Moderating variables that influence the nature of exercise are difficult to control in empirical studies, restricting interstudy comparisons. Most studies to date have used "good sleepers," so the margin for improvement was limited; more recent studies on sleep-compromised populations demonstrate greater improvements. Whether it is the exercise per se or the attendant improvements in lifestyle, wellbeing, and mood that improve sleep, it appears that structured exercise is a valid component of sleep-hygiene routines.
Source: International SportMed Journal 2, pp 1 –9 (2001)More Less
Regular participation in physical exercise has been associated with a diverse number of physical health benefits. Those who are physically active might, however, also experience a variety of positive psychological consequences. Physical activity has been associated with reductions in both depressive symptoms and anxiety. The adoption of a physically active lifestyle is often accompanied by an improvement in selfesteem. Despite these benefits, exercise intervention programs are seldom successful in achieving long-term compliance. Issues relating to compliance optimization are discussed.
Author Andrea T. WhiteSource: International SportMed Journal 2, pp 1 –8 (2001)More Less
Multiple sclerosis (MS) can cause a wide range of impairments involving sensory, motor, and/or cognitive functions. Fatigue, often severe, affects about 85% of MS patients and, along with other symptoms, leads to decreased mobility and reduced quality of life. Although exercise is beneficial for individuals with MS, several precautions should be taken to avoid worsening symptoms. Exercise programs must be designed to activate working muscles but avoid overload of weak muscles, which would cause abnormal fatigue or conduction block. Guidelines for MS patients must be fashioned according to the individual's specific symptoms and functional abilities. Vigorous physical activity should be discontinued during an MS exacerbation, especially when the patient is being treated with corticosteroids. Finally, a safe, comfortable exercise environment is essential for MS patients. Factors of most concern are heat sensitivity, excessive fatigue, and poor balance and coordination. The benefits of exercise in MS patients include improved cardiovascular and muscular fitness, reduced fatigue, and enhanced quality of life.
Source: International SportMed Journal 2, pp 1 –14 (2001)More Less
The relationship among fatigue, intensity of effort, and pacing strategies during exercise has not been conclusively defined. The article describes 3 models of fatigue. In the first, the peripheral model, muscle metabolic factors control or dictate the onset of fatigue and the reduction or termination of exercise. In the second model, the central-teleoanticipatory model, subconscious-brain centers or functional activities set predetermined exercise activity in a feedforward manner, maintaining a reserve of functional capacity as a protective mechanism. In the third model, the cognitive-discussion model, the sensation of fatigue itself controls exercise intensity in a feedforward manner within the framework of the subconscious teleoanticipation limits, using prior activity as the comparator to set and maintain levels of exercise intensity. Physiological and anatomical structures available in the latter 2 models to control exercise intensity might include central pattern generators, multiple-joint spatial-pattern recruitment, and motor-unit-recruitment variation.
Author Louise M. BurkeSource: International SportMed Journal 2, pp 1 –7 (2001)More Less
Amino-acid supplements have been marketed to athletes for the last 2 decades. The claims that the amino acids they contain are superior to those found in food are not well supported, nor has it been shown that they achieve a superior functional outcome. Although there is some evidence that taking amino-acid supplements after exercise might promote better net muscle-protein retention, it is equally likely that this effect can be achieved from eating food containing amino acids. In fact, coingestion of carbohydrate is important in maximizing the effect. There is a theory that "central fatigue" can occur during prolonged exercise as a result of changes in plasma ratios of free tryptophan to branched-chain amino acids (BCAAs), leading to an increase in serotonin production. Although it has been proposed that supplementation with BCAAs might attenuate the development of central fatigue, studies have not shown a clear benefit in prolonged exercise. In fact, ingesting carbohydrate during exercise will also produce a metabolic profile attenuating the development of central fatigue.