The resting metabolic rate (RMR) and thermic effect of a meal (TEM) were determined in 13 low-energy intake (LOW) and 11 adequate-energy intake (ADQ) male endurance athletes. The LOW athletes reported eating 1,490 kcal·day-1 less than the ADQ group, while the activity level of both groups was similar. Despite these differences, both groups had a similar fat-free mass (FFM) and had been weight stable for at least 2 years. The RMR was significantly lower (p<0.05) in the LOW group compared to the values of the ADQ group (1.19 vs. 1.29 kcal·FFM-1·hr-l, respectively); this difference represents a lower resting expenditure of 158 kcal·day-1. No differences were found in TEM between the two groups. These results suggest that a lower RMR is one mechanism that contributes to weight maintenance in a group of low- versus adequate-energy intake male athletes.
Janice Thompson, Melinda M. Manore and James S. Skinner
Christine A. Dueck, Kathleen S. Matt, Melinda M. Manore and James S. Skinner
The purpose of this study was to determine the effect of a 15-week diet and exercise intervention program on energy balance, hormonal profiles, body composition, and menstrual function of an amenorrheic endurance athlete. The intervention program reduced training 1 day/week and included the use of a sport nutrition beverage providing 360 kcal/day. Three eumenorrheic athletes served as a comparison group and were monitored over the same 15-week period. The amenorrheic athlete experienced a transition from negative to positive energy balance, increased body fat from 8.2 to 14.4%, increased fasting luteinizing hormone (LH) from 3.9 to 7.3 mlU/ml, and decreased fasting cortisol from 41.2 to 33.2 pg/dl. The eumenorrheic subjects showed a 0.4% reduction in body fat, a decrease in follicular phase levels of LH from 7.9 to 6.5 mlU/ml, and no change in cortisol. These results suggest that nonpharmacological treatment can contribute to reestablishing normal hormonal profiles and menstrual cyclicity in amenorrheic athletes.
Sheila A. Kopp-Woodroffe, Melinda M. Manore, Christine A. Dueck, James S. Skinner and Kathleen S. Matt
Chronic energy deficit is one of the strongest factors contributing to exercise-induced menstrual dysfunction. In such cases, macro- and micronutrient intakes may also be low. This study presents the results of a diet and exercise training intervention program, designed to reverse athletic amenorrhea, on improving energy balance and nutritional status in 4 amenorrheic athletes. The 20-week program provided a daily sport nutrition supplement and 1 day of rest/week. The intervention improved self-reported energy intake (El) and balance in all participants. The program increased protein intakes for the 3 athletes with a protein deficit to within the recommended levels for active individuals. Micronutrient intakes increased, as did serum concentrations of vitamin B12, folate, zinc, iron, and ferritin. These results indicate that some amenorrheic athletes have poor nutritional status due to restricted Els and poor food selections. A sport nutrition supplement may improve energy balance and nutritional status in active amenorrheic women.
Derek T. Smith, Stacey Judge, Ashley Malone, Rebecca C. Moynes, Jason Conviser and James S. Skinner
Reduced strength, balance, and functional independence diminish quality of life and increase health care costs. Sixty adults (82.2 ± 4.9 years) were randomized to a control or three 12-week intervention groups: bioDensity (bD); Power Plate (PP) whole-body vibration (WBV); or bD+PP. bD involved one weekly 5-s maximal contraction of four muscle groups. PP involved two 5-min WBV sessions. Primary outcomes were strength, balance, and Functional Independence Measure (FIM). No groups differed initially. Strength significantly increased 22–51% for three muscle groups in bD and bD+PP (P < .001), with no changes in control and PP. Balance significantly improved in PP and bD+PP but not in control or bD. bD, PP, and bD+PP differentially improved FIM self-care and mobility. Strength improvements from weekly 5-min sessions of bD may impart health/clinical benefits. Balance and leg strength improvements suggest WBV beneficially impacts fall risk and incidence. Improved FIM scores are encouraging and justify larger controlled trials on bD and bD+PP efficacy.