Petra B. Schuler

Accuracy and repeatability of the Yale physical activity survey in assessing physical activity of older adults.

The purpose of this study was to extend the initial evaluation of the Yale Physical Activity Survey to assess physical activity in older adults. The survey yields three indicators of physical activity reflecting activities performed during a typical week of the previous month (Total Time, Total Energy Expenditure) and the past month (Total Activity Summary Index). Questionnaire validity was studied in 56 men and women, ages 56 to 86 years, by comparing the average of 3- or 7-day 24-hr. physical activity records (n = 56), predicted maximal oxygen consumption (VO2 max) (n = 23) and the sum of three skinfold measurements. Two-week repeatability was estimated by calculating an intraclass coefficient using an analysis of variance with repeated measures. Spearman ps were used to study questionnaire validity. Analysis showed the survey was easily administered and scored and exhibited moderate-to-good repeatability. For the first administration the Total Energy Expenditure Index was significantly associated with the physical activity diary (r = .27). On the second administration, correlations were significant for the physical activity diary with the Total Energy Expenditure Index (r = .30), the Total Activity Summary Index (r = .36), and the Total Time Index (r = .27), and for VO2 max and the Total Time Index (r = .49) and Total Activity Summary Index (r = .64). Relative to the criterion measures used in this study, some validity was evident for the second administration in this relatively active and healthy sample of older adults.

Body-Shape Perceptions in Older Adults and Motivations for Exercise

This study examined the relationships among age, sex, exercise and body-image dissatisfaction in older adults and evaluated the role of body-shape dissatisfaction as a motivation to exercise. A pencil-and-paper questionnaire was administered to 175 older adults (101 women and 74 men) ranging in age from 50 to 98 years (M = 72 yr., SD = 9) to obtain general information, information regarding exercise participation, motivations for exercise and body-shape perceptions. A body-shape dissatisfaction score was calculated using the difference between the participants choice for current and ideal body shape from a nine-figure body-silhouette scale. Present study findings suggested that both older adult men and women expressed a desire for a thinner body shape independent of age and current participation in exercise. In addition, the results indicated that body-shape dissatisfaction did not motivate this sample to engage in regular exercise; physical health and physical fitness emerged as the most important motivations to exercise.

A comparison of cytokine responses during prolonged cycling in normal and hot environmental conditions.

Purpose Components of immune function are affected by physical activity in an adverse environment. The purpose of this study was to compare plasma differences in inflammatory cytokines including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), in addition to the stress hormone cortisol, during prolonged cycling under normal and hot environmental conditions in elite cyclists. Methods and design Six trained elite male cyclists (27 ± 8 years; 75.5 ± 4 kg; maximum oxygen uptake [VO2max] = 66 ± 6 mL/kg/min, mean ± SD). The cyclists biked for 2.5 h at their prescribed 60% maximum exercise workload (Wmax) or 75% VO2max either in an environmental chamber set at 15°C and 40% relative humidity (NEUTRAL) or at 35°C and 40% relative humidity (HOT). The cyclists were given 4 mL of water/kg body weight every 15 min under both conditions. Results Total cortisol concentrations were elevated (P < 0.05) immediately postexercise and 12 h postexercise in both the NEUTRAL and HOT conditions. TNF-α concentrations were only significantly (P = 0.045) elevated postexercise in HOT conditions. During the HOT conditions, a significant (P = 0.006 and 0.007, respectively) difference in IL-6 was seen immediately after and 12 h postexercise. During the NEUTRAL condition, IL-6 was only significantly elevated postexercise (P < 0.05). Conclusions Heat exposure during a long bout of exercise is sufficient to elicit stress response in elite cyclists. However, the degree of release of anti-inflammatory and proinflammatory cytokines might be related to several factors that include the athlete’s fitness level, hydration status, exercise intensity, and length of exposure to hot environments.

Use of self-reports of physical fitness as substitutes for performance-based measures of physical fitness in older adults

The purpose of the present study was to evaluate the association between self-reported physical fitness and performance-based measures of physical fitness in older adults. The specific components of physical fitness evaluated included aerobic endurance, muscular strength, and flexibility. Adults (25 men and 47 women) ranging in age from 56 to 92 years (M age = 75 yr.) were recruited from the local community. Generally, the associations between self-reported and performance-based measures of physical fitness were low to moderate (r = .30–.01). Based on these findings, self-reports of physical fitness should not be used as substitutes for performance-based measures of physical fitness in older adults. Furthermore, present findings suggest that older adults, when asked to rate subcomponents of physical fitness, may not do so but rather evaluate a more general concept of physical fitness with aerobic endurance as the dominant factor.

Effects of 4:1 carbohydrate/protein solution versus a carbohydrate-alone solution on IL-6, TNF-α, and cortisol during prolonged cycling in hot environmental conditions

Purpose Intense or prolonged exercise and/or heat stress might affect the immune system creating a response similar to trauma or inflammation, resulting in an increase in the susceptibility to viral infections. For example, during prolonged exercise, inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and the stress hormone cortisol are produced and released. Although there have been several studies examining the effects of nutritional supplementation on cytokine release in elite athletes, few studies have investigated the effects of different energy drinks during exercise in adverse environmental conditions. Therefore, the purpose of this study was to compare plasma levels of inflammatory cytokines TNF-α and IL-6, and the stress hormone cortisol, during prolonged cycling under hot environmental conditions while ingesting fluid that contains a ratio of 4:1 carbohydrates and protein (4:1 CHO/PRO) versus a carbohydrate-only drink (CHO). Methods Six male cyclists (aged 27 ± 8 years; weight 75.5 ± 3.4 kg; VO2max = 66 ± 2.7 mL/kg/min, mean ± standard error) rode on a stationary ergometer on two separate sessions for 2.5 hours at 75% VO2max in an environmental chamber set at 35°C and 60% relative humidity. During the first session the cyclists were given 4 mL/kg body weight of a 6% carbohydrate solution every 15 minutes. During the second session they were given 4 mL/kg body weight of a 4:1 carbohydrate/protein drink every 15 minutes. Subjects were not aware of which drink they were given in each trial. Blood samples were taken pre-, immediately post-, and 12 hours post-exercise. SPSS (IBM Corp, Armonk, NY) was utilized to analyze data through repeated measures analysis of variance. Results No significant main effect was observed between treatments in either cortisol (P = 0.97), IL-6 (P = 0.64), or TNF-α (P = 0.37) responses. Total cortisol concentrations were significantly elevated (P < 0.05) immediately post-exercise, and from pre- to 12 hours post-exercise with both the 4:1 CHO/PRO and the CHO-alone solutions. TNF-α concentrations were only significantly (P = 0.045) elevated post-exercise with the CHO-alone solution. A significant (P < 0.05) elevation of IL-6 was seen immediately post-exercise and 12 hours post-exercise with both the CHO-alone and 4:1 CHO/PRO solutions. Conclusions Consuming a 4:1 CHO/PRO solution during prolonged cycling under hot environmental conditions has comparable effects on inflammatory cytokines to drinking a CHO-alone solution.

Differences in African-American and Euro-American athletes' perceptions of treatment by coaches.

Analysis of responses from 418 respondents from southern USA (198 African-American, 220 Euro-American adults) in 53 different locations at 4 colleges and universities showed that African-American and Euro-American high school and college athletes differed significantly in agreement on 4 of 12 statements representing their treatment by coaches. African-American athletes rated their coaches significantly more negatively on these items. Implications for coaches lie in planning, design and evaluation of coaching behaviors by African-American athletes.

Estimation of arm maximal oxygen uptake (VO2max) from submaximal arm ergometer exercise in young male subjects

The objective of this investigation was to develop a regression equation to predict arm VO2max based on a submaximal arm ergometer exercise. Sixty healthy adult males, from 18 to 29 years of age, completed a symptom‐limited/exhaustive exercise test on a Monark Rehab Trainer (Model 881E) to measure arm VO2max· During the arm crank GXT, a subject exercised at an initial work rate of 30 kgm · min−1, with 30 kgm · min−1 increase in work rate each minute until the subject expressed exhaustion. Subjects also completed a 5‐min submaximal exercise on a Monark Rehab Trainer at a work rate that elicited a steady state heart rate between 110 and 150 bpm. This exercise session was preceded by a 3‐min warm‐up at a work rate at 30 kgm · mm−1. Multiple regression analysis to predict arm VO2max (ml · min−1) yielded the following predictor variables: (a) submaximal heart rate (SHR) (bpm) (b) submaximal exercise work rate (WR) (kgm ‐min−1) (c) body weight (BW) (kg) and (d) age (yr). This analysis produced the following reg...