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Compared physical activity patterns among Asian, African, white, and Hispanic, American college students. Self-report data indicated that nearly half of the sample did not engage in vigorous physical activity, and 16.7 percent were inactive. Weight-training, youthful physical activity, and television viewing accounted for a significant portion of the variance in physical activity levels. Females, especially minorities, were especially physically inactive. (SM)

Investigated the effects of carbohydrate substrate availability on ratings of perceived exertion (RPE) and hormonal regulation during a competitive marathon. Data on marathon runners randomly assigned to receive carbohydrate or placebo indicated that those who ingested carbohydrate rather than placebo beverages were able to run at a higher intensity while reporting a non-significant difference in RPEs during a competitive race. (SM)

The objective of this study was to evaluate the utility of ultrasound velocity (UV) to detect changes in the hydration status of wrestlers after undergoing acute dehydration and a 2-hour rehydration period. Forty-seven NCAA wrestlers (mean [+ or -] SEM); age 19.1 [+ or -] 0.2 years, height 1.73 [+ or -] 0.1 m, body mass (BM) 79.4 [+ or -] 2.4 kg were tested in euhydrated, dehydrated, and a 2-hours rehydrated conditions. Hydration status was quantified by measuring changes in plasma osmolarity ([P.sub.osm]), urine osmolarity ([U.sub.osm]), urine specific gravity ([U.sub.sg]), and BM. Ultrasound velocity was measured at 1 MHz using 1.5-microsecond duration tone burst in the soleus muscle. Significant changes (p < 0.001) in UV during periods of dehydration (BM change = -3.6 [+ or -] 0.14%) (UV = +2.18 m x [s.sup.-1]) and rehydration (BM change = +2.8 [+ or -] 0.12%) (UV = -2.89 m x [s.sup.-1]) were found. Significant main effects (p < 0.001) were also found for [U.sub.sg], [U.sub.osm], and [P.sub.osm] during dehydration. The change in [P.sub.osm] from the 1 to 2-hour rehydration time period significantly correlated to the change in UV during the same time period (r = 0.27, p < 0.001). This study demonstrates that changes in UV correspond to the changes of [P.sub.osm] [U.sub.sg], [U.sub.osm], and BM during acute dehydration and rehydration in collegiate wrestlers. The use of ultrasound measures may have potential application as an alternative field-based method to assess the hydration status of collegiate wrestlers although future research is warranted. KEY WORDS wrestling, deyhdration, athletes, euhydration, plasma osmolarity

The objective of this study was to evaluate the effects of three different drinks (commercially formulated water, bottled water, and a carbohydrate-electrolyte beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-one athletes were recruited to perform a randomized, crossover study comparing the effectiveness of commercially formulated water, carbohydrateelectrolyte (60/0 or 60 g.[L.sup.- 1]), or regular bottled water (placebo) in promoting rehydration after a 30/0 reduction in body mass. Urine specific gravity [U.sub.sg]), urine osmolarity ([U.sub.osm]), plasma osmolarity ([P.sub.osm]), and plasma volume were measured pre--and post-dehydration and at 1 hour after rehydration. Statistical analyses used a 3 (conditions) X 3 (times) repeated measures analysis of variance. Significant (p < 0.01) interactions were found for [P.sub.osm] [U.sub.osm] and [U.sub.sg.] [P.sub.osm], returned to baseline levels and [U.sub.osm] remained in a lower balance after 1 hour of rehydration in the trials of the commercially formulated water and regular bottled water. No significant interactions were found for plasma volume shift. The findings of this study demonstrate that the commercially formulated water was no more effective in promoting rehydration than either a carbohydrate-electrolyte solution or plain water in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1 hour when consuming 100% of their body weight loss. KEY WORDS fluid balance, electrolyte balance, rehydration, dehydration, plasma osmolarity

The purpose of the present study was to investigate the relationship between carbohydrate energy substrate and the perception of exertion during resistance exercise. Thirty strength-trained subjects were randomized to a carbohydrate group (C) or a placebo group (P), and lifted weights for 2 hours (4 sets; 10 repetitions maximum; 10 exercises; 2-3-minute rest intervals). Subjects ingested 10 ml*[kg.sup.-1]*[h.sup.-1] of 6% carbohydrate or placebo beverages during the resistance-training bout. The 15-category Borg Perceived Exertion Scale was used to assess overall body (RPE-O) and active muscle (RPE-AM) perceived exertion after completion of the last repetition in each set for each exercise. No significant differences were found between the C and P groups for either RPE-O or RPE-AM, with the exception of RPE-O for the upright row and back squat (p < 0.05). Carbohydrate supplementation exerted no attenuating effect on ratings of perceived exertion (RPE) during resistance training. Key Words. RPE, strength training, weightlifting

This investigation compared percent fat obtained via underwater weighing using measured and predicted residual lung volume (RLV) in euhydrated and hypehydrated collegiate wrestlers (N = 67). RLV was measured using [O.sub.2] rebreathing or [0.sub.2] dilution and predicted using 3 equations--Equation 1:(0.019 x height [cm]) + (0.0115 x age [years])--2.24; Equation 2: (0.017 x age [years]) + (0.06858 x height [in.])--3.477; and Equation 3: (0.0275 age [years]) + (0.0189 height [cm])--2.6139. Percent fat determined using RLV Equation 2 did not differ from the value obtained using measured RLV in the euhydrated (10.9 (+ or -] 5.1 vs. 11.5 [+ or -] 5.6% fat) or hypohydrated (10.8 [+ or -] 5.1 vs. 12.3 [+ or -] 5.6% fat) trials. All other percent fat values differed (p < 0.05) from the value obtained using measured RLV in euhydrated subjects. The use of RLV Equation 2 may be a practical alternative to measured RLV in determining percent fat in euhydrated and hypohydrated collegiate wrestlers. KEY WORDS. percent fat, hydration status, hydrostatic weighing

Ratings of perceived exertion (RPE) and their relation to selected physiological mediators during endurance exercise have been limited to laboratory settings. The present study characterized the pattern of change in perceptual responses and examined the relation between RPE and selected physiological variables during along competitive sporting event, i.e., an ultramarathon race (68 km). A single-group design was employed in which all of the 28 subjects provided their perceptual ratings (11.9 [+ or -] 0.2) and heart rate (HR) (138 [+ or -] 3) periodically (every 5 km) throughout the ultramarathon, and selected physiological responses were measured before, once during (32 km), and immediately after the race. Runners drank approximately 1,000 ml of carbohycarbohydrate beverage each hour (60 gm carbohydrate hr. (-1)) and ate 2 or 3 carbohydrate gel packs the per hour (25 gm each [-1]). RPE increased significantly throughout the course of the ultramarathon. No significant correlations were found between RPE and HR at any time throughout the ultramarathon. RPE averaged 10.4 [+ or -] 0.4 at the conclusion of the race. Subjects maintained 76.9 [+ or -] 1.1% of maximal heart rate; however, there was a tendency for heart rate to drop significantly after 32 km. Significant time main effects were found for secrum glucose, insulin, and cortisol throughout the race. However, no significant correlations were found between RPE and any of these physiological mediators. These data indicate that during an ultramarathon race there is a progressive increase in RPE without an accompanying increase in HR or decrease in blood glucose. Therefore, during competitive self-paced exercise the perceptual responses may be mediated through other neurological and physiological mechanisms.

This article discusses the physiological changes a wrestler undergoes while preparing for Olympic trials. An analysis of body weight, muscle strength, anaerobic power, body composition, and food habits is presented.

Effects of in-season pyruvate and creatine supplementation on anaerobic performance and body composition in 42 American football players have been studied and it was found that peak rate of force development for static vertical jump (SVJ) power output significantly greater for the creatine group vs the placebo and pyruvate groups. Creatine and the combination supplement helped training adaptations associated with body mass/composition, maximum strength and SVJ, but pyruvate alone was not effective.

Obesity has been linked with a wide variety of health problems including hypertension, dyslipidemia, diabetes mellitus, certain forms of cancer, cardiovascular disease, and gallstones (1). Clinical and epidemiologic data also [...], Objective To compare immune function in obese and nonobese subjects. Design Obese and nonobese subjects were compared cross-sectionally. To test for the influence of other factors on immunity, aerobic fitness, psychological well-being, and serum levels of glucose, triglycerides, and cholesterol were measured and included in multiple regression models to determine their comparative effects. Subjects/setting Community-based subjects included 116 obese women (age = 44.3±9.7 years, body mass index = 33.2±6.5) and 41 nonobese women (age = 42.2±10.9 years, body mass index = 21.2±1.9). Statistical analyses performed Independent t tests, Pearson product moment correlations, and stepwise multiple regression procedures. Results Obesity was linked to elevated leukocyte and lymphocyte subset counts (except for natural killer and cytotoxic/suppressor T cells), suppressed mitogen-induced lymphocyte proliferation (an index of T- and B-cell function), higher monocyte and granulocyte phagocytosis and oxidative burst activity, and normal activity of natural killer cells. Applications/conclusions These data support the contention that obesity is associated with alterations in immune function. Further research is needed to link immunosuppression with the previously reported elevated risk of infection among the obese. J Am Diet Assoc. 1999;99:294-299.