G. Dennis Wilson

Comparison of the BOD POD with the four-compartment model in adult females.

PURPOSE This study was designed to compare the accuracy and bias in estimates of total body density (Db) by hydrostatic weighing (HW) and the BOD POD, and percent body fat (%fat) by the BOD POD with the four-compartment model (4C model) in 42 adult females. Furthermore, the role of the aqueous and mineral fractions in the estimation of body fat by the BOD POD was examined. METHODS Total body water was determined by isotope dilution ((2)H(2)0) and bone mineral was determined by dual-energy x-ray absorptiometry. Db and %fat were determined by the BOD POD and HW. The 4C model of Baumgartner was used as the criterion measure of body fat. RESULTS HW Db (1.0352 g x cm(-3)) was not statistically different (P = 0.35) from BOD POD Db (1.0349 g x cm(-3)). The regression between Db by HW and the BOD POD significantly deviated from the line of identity (Db by HW = 0.90 x Db by BOD POD + 0.099; R(2) = 0.94). BOD POD %fat (28.8%) was significantly lower (P < 0.01) than %fat by the 4C model (30.6%). The regression between %fat by the 4C model and the BOD POD significantly deviated from the line of identity (%fat by 4C model = 0.88 x %fat by BOD POD + 5.41%; R(2) = 0.92). BOD POD Db and %fat showed no bias across the range of fatness. Only the aqueous fraction of the fat-free mass (FFM) had a significant correlation with the difference in %fat between the 4C model and the BOD POD. CONCLUSION These data indicate that the BOD POD underpredicted body fat as compared with the 4C model, and the aqueous fraction of the FFM had a significant effect on estimates of %fat by the BOD POD.

Lipid-lowering effect of a dietary chromium (III)—Nicotinic acid complex in male athletes

Abstract Exercise-induced chromium (Cr) losses and marginal Cr intakes may place athletes in a suboptimal state for Cr nutritional status, possibly resulting in impaired insulin function. The purpose of this study was to assess the effects of a synthetic trivalent Cr-nicotinic acid (NA) supplement on insulin controlled variables in athletes. Thirty-four college-age male bodybuilders (BB) were randomly assigned to three groups: placebo (P), n=11; 200 μg Cr−1.8 mg NA (1X), n=12; or 800 μg Cr−7.2 mg NA (4X), n=11. Supplements were ingested daily for 8 weeks and training was controlled. Twelve hr fasting insulin, glucose, total cholesterol (TC), triglyceride, HDL-cholesterol, TC:HDL, LDL-cholesterol, and one hr post-challenge insulin and glucose values were determined at pre- and post-supplementation periods. All pre-supplementation values were within normal ranges. ANOVAs revealed two significant interactions. Mean TC in the P group increased from 139.9 to 153.4 mg/dl, yet decreased from 147.9 to 126.8 mg/dl and 159.2 to 131.3 mg/dl in the 1X and 4X groups, respectively (p

Heart Rate and Lactate Levels During Weight-Training Exercise in Trained and Untrained Men.

In brief: The effects of squatting exercise on heart rate and blood lactate levels were studied in five trained and five untrained men between the ages of 22 and 37. The subjects performed squats (sets of ten repetitions until exhaustion), resting for 2 1/2 minutes between sets. Total positive work was estimated with the following formula: (bar mass + body mass) X vertical displacement X repetitions. Heart rate, lactate, and rating of perceived exertion were measured immediately before exercise, after each set, and five minutes after reaching exhaustion. The trained subjects performed more total work and had higher heart rates and lactate levels at exhaustion than the untrained subjects, though heart rates and lactate levels were lower for trained subjects at a given bar mass or submaximal work load. The findings suggest that weight training may cause adaptations that result in reduced fatigue and/or enhanced recovery.

The physiologic effects of eight weeks of aerobic dance with and without hand-held weights:

There are few reports concerning the physiologic alter ations that occur following a specified period of aerobic dance. Further, no data exist to describe the physio logic changes or potential risk associated with using hand-held weights during aerobic dance. The purpose of this study was to determine the changes in maximum oxygen uptake (VO2 max) and body composition follow ing 8 weeks of aerobic dance using hand-held weights (Heavyhands, AMF, Jefferson, lA). Twenty-eight college females volunteered for the study. All subjects were given a preoxygen and postoxygen uptake (VO2 max) treadmill test. Body composition was measured by taking the sum of five skinfold sites and determining the percent change following training. Subjects were randomly assigned to a hand-held weight or nonhand held weight group. No significant differences (P < 0.05) existed between groups for VO2 max and body com position after 8 weeks of traini ng. However, a significant improvement (P < 0.05) in VO2 max was found within the hand-held weight (37.7 to 42.6) and in the nonhand held weight group (36.5 to 41.9). Complaints from subjects included transient aches and pains in the shoulder area during the first 3 weeks as a result of hand-held weight use. These findings suggest that hand-held weights may be used safely but do not increase the work load sufficiently above that of aerobic dance alone to significantly modify VO2 max or body composition.