The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

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Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise

The purpose of this Position Stand is to provide an overview of issues critical to understanding the importance of exercise and physical activity in older adult populations. The Position Stand is divided into three sections: Section 1 briefly reviews the structural and functional changes that characterize normal human aging, Section 2 considers the extent to which exercise and physical activity can influence the aging process, and Section 3 summarizes the benefits of both long-term exercise and physical activity and shorter-duration exercise programs on health and functional capacity. Although no amount of physical activity can stop the biological aging process, there is evidence that regular exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions. There is also emerging evidence for significant psychological and cognitive benefits accruing from regular exercise participation by older adults. Ideally, exercise prescription for older adults should include aerobic exercise, muscle strengthening exercises, and flexibility exercises. The evidence reviewed in this Position Stand is generally consistent with prior American College of Sports Medicine statements on the types and amounts of physical activity recommended for older adults as well as the recently published 2008 Physical Activity Guidelines for Americans. All older adults should engage in regular physical activity and avoid an inactive lifestyle.

Exercise and physical activity for older adults

Objectives—Although the effects of exercise on neurocognition have been the subject of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale randomized controlled trials (RCTs). Methods—We conducted a systematic literature review of RCTs examining the association between aerobic exercise training on neurocognitive performance conducted between January, 1966 and July, 2009. Suitable studies were selected for inclusion according to the following criteria: randomized treatment allocation, mean age ≥ 18 years of age, duration of treatment > 1 month, incorporated aerobic exercise components, exercise training was supervised, the presence of a nonaerobic-exercise control group, and sufficient information to derive effect size (ES) data. Results—Twenty-nine studies met inclusion criteria and were included in our analyses, representing data from 2,049 participants and 234 effect sizes. Individuals randomly assigned to receive aerobic exercise training demonstrated modest improvements in attention and processing speed (g = .158 [95% CI: .055 to .260], P = .003), executive function (g = .123 [95% CI: .021 to . 225], P = .018), and memory (g = .128 [95% CI: .015 - .241], P = .026). Conclusions—Aerobic exercise training is associated with modest improvements in attention and processing speed, executive function, and memory, although the effects of exercise on working memory are less consistent. Rigorous RCTs are needed with larger samples, appropriate controls, and longer follow-up periods.

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Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials.

The authors describe the effects of practice conditions in motor learning (e.g., contextual interference, knowledge of results) within the constraints of 2 experimental variables: skill level and task difficulty. They use a research framework to conceptualize the interaction of those variables on the basis of concepts from information theory and information processing. The fundamental idea is that motor tasks represent different challenges for performers of different abilities. The authors propose that learning is related to the information arising from performance, which should be optimized along functions relating the difficulty of the task to the skill level of the performer. Specific testable hypotheses arising from the framework are also described.

Challenge Point: A Framework for Conceptualizing the Effects of Various Practice Conditions in Motor Learning

Physical activity is beneficial for healthy ageing. It may also help maintain good cognitive function in older age. Aerobic activity improves cardiovascular fitness, but it is not known whether this sort of fitness is necessary for improved cognitive function. Eleven studies of aerobic physical activity programmes for healthy people over the age of 55 years have been included in this review. Eight of these 11 studies reported that aerobic exercise interventions resulted in increased fitness of the trained group and an improvement in at least one aspect of cognitive function. The largest effects were on cognitive speed, auditory and visual attention. However, the cognitive functions which improved were not the same in each study and the majority of comparisons yielded no significant results. The data are insufficient to show that the improvements in cognitive function which can be attributed to physical exercise are due to improvements in cardiovascular fitness.

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Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment

The purpose of this study was to examine the effects of different durations of static stretching on dynamic balance. Women (N = 28) were tested before and after 2 stretching interventions and a control condition on 3 separate days, at least 48 hours apart. The stretching sessions involved a cycle ergometer warm-up at 70 rpm and 70 W followed by passive stretching of the lower-body muscles. Each stretching position was held at a point of mild discomfort and repeated 3 times with 15 seconds between stretches. In the 2 stretching protocols, the positions were maintained for 15 or 45 seconds. The control condition involved the same cycle ergometer warm-up, with a 26-minute rest period between pre- and posttests. Balance was assessed using the Biodex Balance System. A 2-way repeated-measures analysis of variance was used with the effects of study condition (control, 15 seconds, 45 seconds) and time (pre-, postscores). Post hoc paired t-tests were used when appropriate to determine possible statistical significance between pre- and posttest scores. Analyses indicated no significant main effects for either study condition or time. However, there was a significant condition x time interaction (p < 0.05). Post hoc analyses indicated that the 15-second condition produced a significant improvement in the balance scores (p < 0.01), with no significant effects with the control condition or the 45-second treatment. The results of this study reveal that a stretching protocol of 45-second hold durations does not adversely affect balance when using the current stabilometry testing procedure. Furthermore, a stretching intervention with 15-second hold durations may improve balance performance by decreasing postural instability. Strength and conditioning professionals concerned with reported performance limitations associated with static stretching should consider applying shorter-duration stretching protocols when aiming to improve balance performance.

The acute effects of different durations of static stretching on dynamic balance performance.

Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women. In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure. Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p ≤ 0.05) (52.9 ± 11.1 kg vs. 52.1 ± 11.7 kg) with no significant differences between conditions in 60% 1RM repetitions (p = 0.81). Systolic blood pressure was significantly greater post-exercise, with caffeine (p < 0.05) (116.8 ± 5.3 mmHg vs. 112.9 ± 4.9 mmHg). These findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women.

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Caffeine enhances upper body strength in resistance-trained women

The acquisition and transfer effects of contextual interference (Battig, 1979) were investigated on a coincidence anticipation task. The experimental task required subjects to make predictive judgements so that their responses coincided with the arrival of a light stimulus. Sixty females were selected from an activity questionnaire determining the extent of experience in similar tasks. One half were selected reporting no experience, and the remaining subjects had prior and present involvement in tasks requiring predictive judgements. Battig's (1979) conceptualization of memory was supported for experienced subjects in one transfer task. Experienced subjects who processed the acquisition tasks in high contextual interference (random order of presentation) performed significantly better than novice subjects in the same acquisition context. In addition, acquisition under a random sequence facilitated transfer to a novel task for experienced subjects as compared to acquisition under a constant order ...

The Effects of Contextual Interference on Females With Varied Experience in Open Sport Skills

Limb acceleration and deceleration during exercise on an isokinetic device encounter no machine-offered resistance. The purpose of this study was to quantify the relationship between velocity and range of motion that is sustained at a predetermined isokinetic velocity, termed load range, during concentric knee extension and flexion exercise. Nine male and nine female subjects performed three maximal concentric reciprocal knee extension and flexion repetitions at 60, 120, 180, 240, 360, and 450 degrees/sec. Extension and flexion results revealed a significant (p < 0.05) increase in acceleration and deceleration range of motion while load range significantly decreased with increasing velocity. Males exhibited greater load range and less acceleration range of motion than females at 240, 360, and 450 degrees/sec, while deceleration range of motion was not different between genders at any speed. These results demonstrate an inverse relationship between isokinetic velocity and load range and suggest a need to carefully consider velocity selection when performing exercise on an isokinetic device.

https://www.jospt.org/doi/pdfplus/10.2519/jospt.1995.21.2.107

The effect of velocity and gender on load range during knee extension and flexion exercise on an isokinetic device.

High-intensity interval training (HIT) is characterized by intermittent periods of work and rest and may include work bouts lasting seconds to minutes. HIT has typically been applied to older, diseased, and at-risk populations using longer work intervals (2-4 minutes), whereas more recent definitions of HIT include work intervals of 30 to 60 s. Both traditional endurance training (TET) and HIT exert a peripheral affect increasing the capacity of muscle cells to oxidize substrate via signaling cascades that support the activation of transcription factors that orchestrate the coexpression of nuclear and mitochondrial genes, with HIT triggering these benefits following minutes of training. With 1 exception, reports of central adaptations (eg, increased stroke volume) have been based on longer work intervals (eg, 4 minutes). Recent investigations have tied HIT to increased lipolysis and enhanced insulin sensitivity. HIT favors the activation of oxidative as opposed to hypertrophic pathways. Although the lengt...

Michael Whitehurst

Papers

The acute effects of different durations of static stretching on dynamic balance performance.

Caffeine enhances upper body strength in resistance-trained women

The Effects of Contextual Interference on Females With Varied Experience in Open Sport Skills

The effect of velocity and gender on load range during knee extension and flexion exercise on an isokinetic device.

High-Intensity Interval Training: An Alternative for Older Adults