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PubMed1994

Influence of physical exercise on 5-HT1A receptor- and anxiety-related behaviours.

Treadmill exercise (1 h at 20 m/min) has been shown to increase brain serotonin (5-HT) synthesis/metabolism in 4-day trained rats. This work has analysed whether these changes are associated with (5-HT-dependent or -independent) alterations in pre- and postsynaptic 5-HT1A receptor-mediated behaviours; in addition, the controversial hypothesis that exercised rats are less anxious than sedentary rats was tested in the elevated plus-maze and the social interaction models. Acute administration of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.125-0.5 mg/kg) triggered hyperphagia, forepaw treading, and flat body posture, the amplitude of which were not affected by training or acute exercise. In the elevated plus-maze, training, but not acute exercise, reduced the number of total arm entries. In the social interaction test, trained and acutely exercised rats displayed increased locomotion and decreased defecation, compared to resting rats, but social interaction and rearings were not affected. It is suggested that the aforementioned effects of acute exercise upon 5-HT synthesis/metabolism in short-term trained rats are not associated with changes in 5-HT1A receptor- and anxiety-related behaviours.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed2006

Rural-urban differences in health and health behaviour: a baseline description of a community health-promotion programme for the elderly.

STUDY OBJECTIVE: To (1) describe the setting and design of the Good Ageing in Lahti Region (GOAL) programme; (2) by using the baseline results of the GOAL cohort study, to examine whether living in urban, semi-urban, or rural communities is related to risk factors for chronic diseases and functional disability in ageing individuals. DESIGN: The baseline data of a cohort study of ageing individuals living in three community types (urban, semi-urban, rural). Data were collected by two questionnaires and laboratory assessments. SETTING: Fourteen municipalities in the Lahti region (Päijät-Häme County) in Finland. PARTICIPANTS: A regionally and locally stratified random sample of men and women born in 1946-50, 1936-40, and 1926-30. A total of 4,272 were invited and 2,815 (66%) participated. MAIN RESULTS: Elevated serum cholesterol, obesity, disability, sedentary lifestyle (<2 times/week walking), and high fat intake were more prevalent in rural vs. urban and semi-urban communities. After adjustment for sex, age, education, obesity, diet, physical activity, smoking, and alcohol use, rural communities remained the only community type with increased (p<0.05) probability for high BMI (OR 1.33) and high waist circumference (OR 1.43). CONCLUSIONS: The unfavourable health and lifestyle profile, together with an old population, makes health promotion for elderly citizens a special challenge for rural communities such as those in Päijät-Häme County, Finland. Most, if not all, of the differences in health between the three community types were explained by educational background, physical activity, and smoking.

Aged↗

PubMed2003

Effects of exercise on cardiovascular outcomes in monkeys with risk factors for coronary heart disease.

OBJECTIVE: Exercise reduces the risk for coronary heart disease. However, the mechanisms mediating the beneficial effects of exercise remain ambiguous. In particular, it is uncertain whether exercise inhibits the development of atherosclerosis, a major pathobiologic process underlying heart disease. METHODS AND RESULTS: To address this question, adult male monkeys were fed an atherogenic diet while assigned to one of four experimental conditions for 34 months: 1) runner/no group disruption, ie, "stable" (n=19); 2) runner plus frequent social group disruption, ie, "unstable" (n=19); 3) sedentary/stable (n=15); or 4) sedentary/unstable (n=18). Neither exposure to exercise nor social group disruption significantly affected the resulting coronary artery atherosclerosis extent or lumen areas (all ANOVA values, P>0.05). When compared with sedentary individuals, exercise animals had lower resting heart rates (119.0+/-3 vs 132.0+/-3 bpm, P=0.002), greater echocardiographically measured left ventricular ejection fractions (77.2+/-0.01% vs 73.8+/-0.01%, P=0.02), greater quantitative angiographically measured dilation of coronary arteries to phenylephrine (2.6+/-1% vs -3.7+/-1% change from baseline diameter, P=0.003), and a reduced cortisol response to an adrenocorticotropin challenge. These measures were not significantly affected by social condition. CONCLUSIONS: Thus, exercise improved some measures of cardiovascular health and reduced stress responsivity but did not inhibit progression of coronary artery atherosclerosis or promote positive artery remodeling. It is concluded that exercise may exert cardioprotective effects without influencing atherosclerosis extent.

Adrenocorticotropic Hormone↗

PubMed1991

Critical evaluation of energy intake data using fundamental principles of energy physiology: 2. Evaluating the results of published surveys.

The fundamental principles of energy physiology were used to evaluate the validity of reported energy intake (EI) in 37 published dietary studies of adults providing 68 subgroups when classified according to sex and dietary method. EI was expressed as a multiple of BMR estimated using the reported heights and weights of the study populations (EI:BMR(est)). This ratio was compared with a study-specific cut-off value representing the lowest value for EI:BMR(est) that could, within defined bounds of statistical probability, reflect the habitual energy expenditure of a sedentary life-style. Mean EI:BMR(est) was 1.43 (0.19) compared with an expected requirement of 1.55. In 46 out of the 68 groups (68%), EI:BMR(est) was below the study-specific cut-off value. EI:BMR(est) was 1.37 (SD = 0.13) for women and 1.50 (SD = 0.16) for men (P less than 0.001). This could reflect either better reporting by men or a more active life-style. When categorized according to dietary assessment method, 64%, 88% and 25% of results fell below the acceptable cut-off value for studies by diet records, diet recall and diet history, respectively. These data indicate that dietary assessment methods have a strong bias towards underestimation of habitual energy intake.

Adolescent↗

PubMed2006

Physical activity and feelings of energy and fatigue: epidemiological evidence.

Approximately 20% of adults worldwide report persistent fatigue. Physical activity is a healthful behaviour that has promise for combating feelings of fatigue and low energy. This article summarises the epidemiological literature that examined the association between physical activity and feelings of energy and fatigue. Twelve population-based studies conducted between January 1945 and February 2005 that concurrently measured physical activity and feelings of energy and fatigue were located. All of the studies suggested that there was an association between physical activity and a reduced risk of experiencing feelings of low energy and fatigue when active adults were compared with sedentary peers (odds ratio = 0.61; 95% CI 0.52, 0.72). The effect was heterogeneous and varied according to study design and the energy/fatigue measure used in the study. Because epidemiological comparisons cannot establish direction of causality, standard criteria for evaluating strength of evidence in epidemiological studies (i.e. strength of association, temporal sequence, consistency, dose response and biological plausibility) were used to judge whether the observed association between physical activity and feelings of energy and fatigue suggest causality in the absence of adequate experimental evidence. There was agreement among the studies suggesting a strong, consistent, temporally appropriate dose-response relationship between physical activity and feelings of energy and fatigue. No compelling evidence has confirmed any plausible biological mechanisms that explain the apparent protective effect of physical activity against feelings of low energy and fatigue. Nonetheless, the epidemiological evidence is sufficiently strong to justify better controlled prospective cohort studies and randomised controlled trials.

Adult↗

PubMed2002

Altitudinal variation in parental energy expenditure by white-crowned sparrows.

We used the doubly labeled water technique to measure daily energy expenditure (DEE) during the incubation and feeding nestling stages in two populations of white-crowned sparrows (Zonotrichia leucophrys) - one montane and migratory, the other coastal and sedentary - that differ in thermal environment and clutch size. We assessed the birds' thermal environment by continuously monitoring (among other variables) operative temperature and wind speed both in the open and within bushes and willow thickets occupied by sparrows. From these measurements, we derived several estimates of the birds' thermal environment, including standard operative temperature (T(es)). Shade air temperature and T(es) averaged 6.6 and 10.3 degrees C lower, respectively, at the montane study site during DEE measurements. The montane population's DEE averaged 24% higher than that of the sea-level population (103.6+/-12.2 versus 83.7+/-9.6 kJ day(-1); means +/- S.D., N=31 and 22, respectively), reflecting both its larger brood size (3.7 versus 2.9) and the colder environment. The DEE:BMR ratio was lowest in the sea-level population (2.1 versus 2.6), but neither population worked to their physiological capacity to produce young. DEE was significantly correlated with temperature across populations, with T(es) explaining 42% of the variation in DEE. Statistically removing the effect of temperature by adjusting DEE to a common temperature reduced the difference in DEE between populations by 34% to 87.7 and 100.8 kJ day(-1), respectively, for sea-level and montane populations. Basal and resting metabolic rates were similar in both populations, implying that greater activity in the montane population accounted for its higher temperature-adjusted DEE. Our results indicate that the thermal context within which behavior occurs can significantly affect interindividual variation in DEE. Attempts to assess reproductive effort by measuring DEE should therefore account explicitly for the effect of temperature.

Altitude↗

PubMed2004

Traditional versus agricultural lifestyle among Shuar women of the Ecuadorian Amazon: effects on leptin levels.

Leptin is a key biological marker related to energy balance and development of diabetes and cardiovascular diseases. Its levels are increased in populations with a high degree of the metabolic syndrome. Life history of evolution has, however, largely taken place under the ecological context of hunting and gathering. In this study, we explored whether the first steps of transition to sedentary agriculture involve a change of body composition, plasma leptin concentration, and markers of the metabolic syndrome. A total of 59 healthy Shuar Amerindian women living in 5 isolated communities in the Ecuadorian Amazonian rain forest were examined. Women (n = 33) from the largest and oldest community, Yuwientsa, who are more dependent on agriculture had higher fat mass (11.7 +/- 3.3 v 14.5 +/- 4.0 kg; P = .023) but the same body mass index (24.1 +/- 2.7 v 23.1 +/- 2.8 kg/m2; not significant [NS]) and lean body mass (41.0 +/- 5.0 v 40.2 +/- 6.2 kg; NS) than women (n = 26) from the 4 traditional hunter/gather settlements. Furthermore, women from Yuwientsia had higher leptin (5.5 +/- 3.1 v 4.1 +/- 2.7 ng/mL; P = .021) and plasma insulin levels (49.8 +/- 37.4 v 35.5 +/- 12.7 pmol/L; P = .013). Homeostasis model assessment (HOMA) values (8.8 +/- 4.8 v 6.1 +/- 2.2; P = .004) and plasma triglyceride levels (2.3 +/- 1.0 v 1.7 +/- 0.6 mmol/L; P = .025) as markers of the metabolic syndrome were also increased in the Yuwientsa population. Mean plasma glucagon concentrations were not different between the groups. We conclude that body fat and levels of insulin and leptin are higher in the population more dependent on agriculture for living. In fact, the leptin concentrations from the 4 hunter/gather communities are the lowest mean value ever reported from a population of healthy females. As there are no genetic or biologic differences between the Shuar Indians from the 5 communities, we hypothesize that behavioral responses to a changing environment may be the key to the development of the metabolic syndrome and elevated plasma leptin concentrations.

Adult↗

PubMed2006

Objectively measured physical activity in sixth-grade girls.

OBJECTIVES: To describe the objectively measured physical activity characteristics of a diverse sample of sixth-grade girls, to examine influences on physical activity, and to report compliance with physical activity guidelines. DESIGN: Cross-sectional study. SETTING: Six locations across the United States. PARTICIPANTS: A total of 1578 sixth-grade girls. Accelerometers were worn for 7 days, and data for 6 days were included in the analyses. Main Exposures Race/ethnicity, free or reduced-price lunch, and geographic region. MAIN OUTCOME MEASURES: Six operational definitions of adequate activity (60 or 30 minutes of daily moderate to vigorous physical activity at or above 4.6, 3.8, or 3.0 metabolic equivalents) were used to examine whether girls met physical activity guidelines. RESULTS: Average times spent in sedentary, light, moderate, and vigorous activities were 460, 342, 18, and 6 min/d, respectively. White girls were more active than girls in other race/ethnic groups, and girls who did not receive free or reduced-price lunch were more active than girls who did. Girls in western states were most active. Percentages of girls in compliance with the 6 thresholds for adequate activity varied widely and ranged from 0.6% to 100.0%. CONCLUSIONS: When physical activity is measured objectively and a 4.6-metabolic equivalents cut point for moderate to vigorous physical activity is used, most sixth-grade girls do not meet guidelines for adequate physical activity. One notable finding was the effect of different accelerometer scoring protocols on estimates of compliance. Conceptual and empirical work is needed to define appropriate physical activity for youth using objective physical activity measures.

Child↗

PubMed1999

Contribution of a sedentary lifestyle and inactivity to the etiology of overweight and obesity: current evidence and research issues.

PURPOSE: The etiology of overweight and obesity is clearly multifactorial, but ultimately it is determined by the long-term balance between energy intake and expenditure. This review will consider the effects on body weight and the risk of obesity of sedentary lifestyles, within the context of dietary habits. METHODS: The data from ecological, cross-sectional, and prospective studies that have assessed physical activity and dietary intake and their relationship to body weight were reviewed. RESULTS: Ecological analyses imply that the increase in the prevalence of obesity is more strongly related to lower levels of physical activity than higher energy intakes. However, there is a paucity of pertinent data from cross-sectional or prospective studies. There is some evidence that both a high proportion of dietary fat and low levels of physical activity may increase the likelihood of weight gain. However, even the most comprehensive studies are unable to account for more than a small proportion of the interindividual variance in weight gain, so it is difficult to usefully assess their relative importance. Furthermore, there are insufficient data that pertain to "sedentary lifestyles" to segregate any putative effect from a protective effect of exercise. All the data in this review is NHLBI Evidence category C. CONCLUSIONS: This review provides clear evidence that low levels of physical activity are associated with an increased risk of weight gain and obesity. On balance, the evidence is suggestive of a causal link, but the experimental designs are too weak is provide conclusive evidence. The potential effect of interactions between diet and activity have largely been ignored. To make progress in this area, a number of key issues need to be resolved with regard to the methodology, study design, and statistical analysis of prospective epidemiological studies. In the meantime, data need to be drawn from other sources, particularly those studies designed to elucidate the mechanism of action of diet and physical activity in the etiology of obesity, to establish rational interventions to guide public health policies.

Cross-Sectional Studies↗

PubMed1986

Effects of fenfluramine on food intake, body weight, gastric emptying and brain monoamines in Syrian hamsters.

In the first experiment, dose-inhibition and -time functions are documented for the anorectic effects of d,l-fenfluramine in Syrian hamsters (Mesocricetus auratus). A dose of 20 mg/kg (IP) inhibited feeding for at least 2-4 hr. In the second experiment, chronic treatment of hamsters housed either in running wheels (exercise) or standard (sedentary) conditions with d,l-fenfluramine (20 mg/kg) produced an attenuation of weight gain relative to vehicle-treated controls. However, there was no differential weight loss in the exercising drug-treated group. This result was also obtained using 10 mg/kg d-fenfluramine. In the third experiment, d,l-fenfluramine greatly inhibited gastric emptying of a test meal in hamsters. In the fourth experiment, hamsters were found to sustain only small and transient decreases in brain 5HT and 5HIAA levels after acute or chronic treatment with d,l-fenfluramine. These findings are compared and contrasted with the known effects of fenfluramine in rats. It is concluded that there may be species differences in the impact of fenfluramine on brain function, and that this may not be in any simple way related to the anorexigenic action of this drug.

Animals↗

PubMed2003

Reproductive uncertainty and the relative competitiveness of simultaneous hermaphroditism versus dioecy.

Hermaphroditism is typically associated with a sedentary existence, whereas dioecy is associated with mobility. This pattern is reflected within flowering plants, as dioecious species commonly possess traits that promote high dispersal. We investigated these associations with three population dynamics models (an individual-based simulation and two mathematical models, one deterministic and the other stochastic) that allowed us to examine competition for space between a hermaphroditic and dioecious species from different perspectives. The competing species are identical in every way but their sexual system. Separation of the sexes increases the variances of pollen import and seed dispersal for the dioecious species. These variances propagate through subsequent reproductive processes and ultimately reduce mean recruitment as a result of nonlinear averaging (Jensen's inequality). A dioecious species could overcome this disadvantage simply by producing more gametes than hermaphrodites; however, in line with the association with mobility, selection on dioecious species should also favor traits that reduce reproductive uncertainty, such as extensive dispersal.

Biological Evolution↗

PubMed2006

Risk of obesity enhanced by poor physical activity in high school students.

BACKGROUND: The aim of this study was to elucidate the interactions between a family history of obesity and poor physical activity. METHODS: A case-control study was performed based on medical check data for all first year high school students admitted to Aichi Prefectural public high schools in the 2004 academic year. Prior to the post-admission medical check up, all students received an interview sheet containing questions on family history of obesity and extent of physical activity. Experienced nurses measured body mass and height. Valid answers and measurements were obtained from 20,155 boys and 19,682 girls. RESULTS: A family history of obesity, reluctance to exercise, current and recent past sedentary lifestyles each significantly increased risk of obesity (body mass index [BMI] >or= 25) and severe obesity (BMI >or= 30) in both boys and girls. Two-way ANOVA revealed that a family history of obesity, associated with poor exercise, positively affected BMI in both boys and girls. Moreover, significant positive interaction was found between a family history of obesity and each of the unfavorable physical activity conditions. Synergistic effects (synergy indexes >1) increasing risk of obesity were noted in both boys and girls when a family history of obesity overlapped with reluctance to exercise, current physical inactivity, or recent physical inactivity. CONCLUSION: Overlapping of family history of obesity and exercise risk factors synergistically increase the BMI and risk of obesity in both boys and girls. Intervention to promote exercise in adolescents who have obese family member(s) should be encouraged.

Adolescent↗

PubMed1993

Dietary intake and health habits of healthy, retired, elderly men.

Retired, non-sedentary, elderly men (66 to 80 years) participated in this study. Three-day food records, one-week records of daily physical activity and information on health habits and medical and physical activity status were obtained. Analysis of the food records showed a mean total energy intake of 2040 +/- 461 (SD), with carbohydrates contributing 46.7 +/- 10.8% of total energy, fat 34.3 +/- 8.9%, protein 16.9 +/- 3.1%, and alcohol 1.9 +/- 2.7%. Mean consumption of the selected nutrients studied were above the Recommended Dietary Allowances (RDA). The mean activity level in a typical week was 14.6 +/- 6.8 Cooper points. Results of this study suggest that maintaining physical activity and consuming a nutritionally adequate diet may contribute significantly to the maintenance of health and well-being among the elderly and may delay the deterioration of functional capacity which accompanies the normal process of aging.

Age Factors↗

PubMedDate not supplied

Determinants of exercise among children. II. A longitudinal analysis.

BACKGROUND: Research has demonstrated that physical activity serves an important preventive function against the development of cardiovascular disease. The recognition that U.S. children are often sedentary, coupled with the observation that physical activity habits tend to persist into adulthood, has prompted the investigation of exercise determinants consistent with social learning theory. The purposes of the present study were to identify social learning variables relevant to children's exercise and to explore the longitudinal predictive value of the determinants. METHODS: Data were collected from 111 families (N = 54 girls, N = 57 boys) who were interviewed in both Phase 1 (fifth and sixth grades) and Phase 2 (eight and ninth grades) of this study. Data from mothers (N = 111) were collected during both phases; data from 80 fathers were collected at Phase 2 only. RESULTS: The results of simultaneous stepwise regression analyses indicated that child's enjoyment of physical activity was the only consistent predictor of physical activity during Phase 1. At Phase 2, child's exercise knowledge, mother's physical activity, and child's and mother's friend modeling/support emerged as predictors for girls. For boys, child's self-efficacy for physical activity, exercise knowledge, parental modeling, and interest in sports media were important. Longitudinally, mother's self-efficacy, barriers to exercise, enjoyment of physical activity, and child's self-efficacy for physical activity were important for girls. Only child's exercise knowledge predicted boys' physical activity. The addition of information from fathers nearly doubled the explanatory power of the predictors for both genders. CONCLUSIONS: Socialization in the family unit exerts a tremendous influence on health-related behaviors such as exercise. The relative importance of determinants seems to differ for girls and boys and the pattern of these determinants appears to change over time.

Adult↗

PubMed1982

Physical training of lean and genetically obese Zucker rats: effect on fat cell metabolism.

The effects of 6-wk treadmill training program on the metabolism of isolated adipose cells from obese (fa/fa) and lean (Fa/?) Zucker rats were studied. Glucose metabolism and transport, insulin binding, and lipolysis were measured in adipose cells prepared from sedentary control and exercise-trained (ET) lean and/or obese rats. Two- to threefold increases in glucose metabolism were observed in cells from lean and obese ET rats compared with their respective controls. However, the insulin concentrations giving half-maximal stimulation (measuring insulin sensitivity) did not change (approximately 8 microunits/ml in lean and approximately 45 microunits/ml in obese rats). In lean ET rats, glucose transport and maximal glucose metabolic capacity (transport not rate-limiting) were increased twofold and sensitivity of lipolysis to epinephrine was increased three- to fourfold. These were not measured in obese rats. The results suggest that training of both lean and obese Zucker rats increases glucose utilization in adipose cells by increasing both glucose transport and intracellular glucose metabolism. Increased triglyceride turnover is also suggested by the increased sensitivity of lipolysis to epinephrine.

Adipose Tissue↗

PubMedDate not supplied

Health characteristics of U.S. adults by body mass index category: results from NHANES 1999-2002.

OBJECTIVES: We examined self-reported health characteristics, health care utilization, activity patterns, and demographic characteristics of U.S. adults 20 years and over by body mass index (BMI) category. We hypothesized that overweight and obese adults would report fair/poor health more often, report more health provider visits annually, experience more joint pain, report greater limitations in their daily activities, and report more hours of sedentary leisure-time activity than normal-weight adults. METHODS: Self-reported health characteristics of U.S. adults from the National Health and Nutrition Examination Survey (NHANES) 1999-2002 were examined for three BMI categories: normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), and obese (BMI > or = 30.0). Covariates included gender, race/ethnicity, cigarette smoking, and educational attainment. We examined BMI group differences using descriptive and regression methods. RESULTS: Compared to normal-weight individuals, overweight individuals reported fair/poor health more often, more limitations in daily activities, and more health provider contacts. Overweight and obese subjects reported more hours of television watching and video game use compared to normal-weight subjects. CONCLUSION: Our findings are useful to describe the health characteristics of U.S. adults and may be used to anticipate future demand for health services and to support intervention programs that help individuals achieve desirable weight status.

Adult↗

PubMed2003

The prevention of type 2 diabetes--lifestyle change or pharmacotherapy? A challenge for the 21st century.

Diabetes mellitus is occurring in epidemic proportions in many countries. In Australia 7.4% of people over 25 years of age have diabetes (mostly type 2) and comparable or higher prevalences have been reported in the United States and a number of Asian countries. The enormous economic and social cost of this disease makes a compelling case for prevention. Epidemiological studies have shown clearly that type 2 diabetes results from an interaction between a genetic predisposition and lifestyle factors including obesity, sedentary behaviour and both calorie excess and various dietary constituents. The natural history of type 2 diabetes includes a preceding period of impaired glucose tolerance (IGT)/impaired fasting glucose (IFG) which provides an opportunity for targeted intervention within large communities. Lifestyle intervention studies have consistently shown that quite modest changes can reduce the progression from IGT to diabetes by 50-60%. It may, however, not be possible to translate these successful findings to larger cohorts or maintain the lifestyle changes longer term. This has lead to consideration of pharmacotherapy. While small studies with sulphonylureas are inconclusive, benefits have been found for metformin, acarbose and troglitazone. Big intervention studies with ramipril, rosiglitazone, valsartan and nateglinide are underway. Pharmacological intervention raises a whole range of ethical, economic and practical issues not the least of which is the problem of long term therapy of the 'otherwise well'.

Clinical Trials as Topic↗

PubMed1998

Immunological hazards from nutritional imbalance in athletes.

This review examines the influences of nutritional imbalance on immune function of competitive athletes, who may adopt an unusual diet in an attempt to enhance performance. A major increase in body fat can have adverse effects on immune response. In contrast, a negative energy balance and reduction of body mass are likely to impair immune function in an already thin athlete. A moderate increase in polyunsaturated fat enhances immune function, but excessive consumption can be detrimental. Since endurance exercise leads to protein catabolism, an athlete may need 2.0 g/kg protein rather than the 0.7-1.0 g/kg recommended for a sedentary individual. Both sustained exercise and overtraining reduce plasma glutamine levels, which may contribute to suppressed immune function postexercise. A large intake of carbohydrate counters glutamine depletion but may also modify immune responses by altering the secretion of glucose-regulating hormones. Vitamins are important to immune function because of their antioxidant role. However, the clinical benefits of vitamin C supplementation are not enhanced by the use of more complex vitamin mixtures, and excessive vitamin E can have negative effects. Iron, selenium, zinc, calcium, and magnesium ion all influence immune function. Supplements may be required after heavy sweating, but an excessive intake of iron facilitates bacterial growth. In making dietary recommendations to athletes, it is important to recognize that immune response can be jeopardized not only by deficiencies but also by excessive intake of certain nutrients. The goal should be a well-balanced diet.

Amino Acids↗