PHYSIOLOGICAL-EFFECTS OF WEIGHT CYCLING IN FEMALE LIGHTWEIGHT ROWERS

Repeated cycles of weight loss and regain are referred to as weight cy cling. It is a practice of many athletes who must achieve a low body w eight. The purpose of this study was to determine whether a history of weight cycling results in sustained metabolic changes. Healthy female rowers with a history of dieting and weight fluctuation (n = 7) were compared to a control group of rowers who had never dieted (n = 7). An thropometric and metabolic measurements were done at pre-, peak, and o ff-season during a 1-year period. At peak season the weight cyclers re stricted their food intake and lost 4.2 +/- 1.8 kg, and subsequently r egained 4.0 +/- 2.1 kg in the off-season. This was different from the controls (p = .003), who maintained a stable body weight at all times. No other group differences were observed. Resting metabolic rate (RMR ) and triiodothyronine (T3) changed with time (p = .001, p = .000, res pectively) in both groups, which appeared to reflect changes in fat fr ee mass (FFM), not body weight. Long-term metabolic changes were not o bserved in these athletes.