The effects of oral creatine supplementation on muscle phosphocreatine (PCr) concentration, muscle strength, and body composition were investigated in young female volunteers (n = 19) during 10 wk of resistance training (3 h/wk). Compared with placebo, 4 days of high-dose creatine intake (20 g/day) increased (P < 0.05) muscle PCr concentration by 6%. Thereafter, this increase was maintained during 10 wk of training associated with low-dose creatine intake (5 g/day). Compared with placebo, maximal strength of the muscle groups trained, maximal intermittent exercise capacity of the arm flexors, and fat-free mass were increased 20-25, 10-25, and 60% more (P < 0. 05), respectively, during creatine supplementation. Muscle PCr and strength, intermittent exercise capacity, and fat-free mass subsequently remained at a higher level in the creatine group than in the placebo group during 10 wk of detraining while low-dose creatine was continued. Finally, on cessation of creatine intake, muscle PCr in the creatine group returned to normal within 4 wk. It is concluded that long-term creatine supplementation enhances the progress of muscle strength during resistance training in sedentary females.

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effect of oral creatine supplementation (CR; 5 g/day) in conjunction with exercise training on physical fitness was investigated in men between 55 and 75 yr of age (n = 46). A double-blind randomized placebo-controlled (PL) trial was performed over a 6-mo period. Furthermore, a subgroup (n = 20) completed a 1-yr follow-up. The training program consisted of cardiorespiratory endurance training as well as moderate resistance training (2-3 sessions/wk). Endurance capacity was evaluated during a maximal incremental bicycle ergometer test, maximal isometric strength of the knee-extensor muscles was assessed by an isokinetic dynamometer, and body composition was assessed by hydrostatic weighing. Furthermore, in a subgroup (PL: n = 13; CR: n = 12) biopsies were taken from m. vastus lateralis to determine total creatine (TCr) content. In PL, 6 mo of training increased peak oxygen uptake rate (+16%; P < 0.05). Fat-free mass slightly increased (+0.3 kg; P < 0.05), whereas percent body fat slightly decreased (-1.2%; P < 0.05). The training intervention did not significantly change either maximal isometric strength or body weight. The responses were independent of CR. Still, compared with PL, TCr was increased by approximately 5% in CR, and this increase was closely correlated with initial muscle creatine content (r = -0.78; P < 0.05). After a 1-yr follow-up, muscle TCr was not higher in CR than in PL. Furthermore, the other measurements were not affected by CR. It is concluded that long-term creatine intake (5 g/day) in conjunction with exercise training does not beneficially impact physical fitness in men between 55 and 75 yr of age.

Body fat estimation by skinfold-thickness equation appeared to be as accurate as underwater weighing. The refeeding program led to a significant increase in body weight, of which 55.5% was body fat. The mean ratio of fat-free mass to fat mass at the end of the treatment was 3.4:1.

For the first time, body composition has been studied in a very large sample of female anorexia nervosa patients (n 200) using two methods: anthropometry (skinfold thickness) and densitometry (underwater weighing). The concurrent validity of both methods appeared to be good (v 0.84). Although the mean percentage of body fat (13.5) in our sample corresponds with most of the previous reports, the range (4.3-24.8) is great. Our study shows that BMI is not a good measure of fatness. Age and duration of illness were not related to body fat. Percentage fat was found to be different (t 2.76, P < 0.01) according to the diagnostic subtype of anorexia newosa: restricters (12.9) v. bingers and/or purgers (14.7).Anorexia nervosa : Body composition: Antbropometry : Densitometry : Underwater weighingThe decrease in body fat in anorexia nervosa (AN) patients due to a prolonged restriction of oral nutrient intake and weight loss has important physiologial consequences with respect to morbidity and mortality (Russell et al. 1983). Knowledge of body composition in these patients is, therefore, clinically most relevant. Body-composition studies are generally based on the principle that one can estimate the relative proportion of two components: fat mass (FM) and fat-free mass (FFM; water, proteins and minerals). A wide variety of methods, from relatively simple and cheap to sophisticated and expensive ones, are available to measure body composition (for a recent review, see Heymsfield et al. 1995). The published studies on body composition in eating disorders are difficult to compare and mostly based on very small groups. We have found only a few studies (Pirke et al. 1986; Charest-Lilly et al. 1987; Mayo-Smith et al. 1989;Hannan et al. 1990 Hannan et al. , 1993aVaisman et al. 1991;Russell et al. 1994;Young et al. 1994) in which more than fifteen patients have been investigated.In the context of a large research and treatment project on psychological and physiological aspects of how AN patients feel and think about their own body (Probst et al. 1995) we applied two methods of body composition assessment: the densitometric technique of underwater weighing (UWW) and the anthropometric approach of measuring skinfold thickness (SFT). UWW is considered to be the method of reference for body composition with reliability coefficients (test-retest correlations) above r 0-95 and concurrent validity coefficients usually above r 0.80 (Heymsfield et al. 1995). SFT is a classic technique with a generally weaker reliability (but usually above r 0.90). The standard error for prediction of fat percentage from SFT is in general 2.6-3.4 % of body weight, which is not very different from the standard error obtained with UWW. Since SFT measures only subcutaneous adipose tissue, its validity is somewhat lower. The correlation between UWW and SFT ranges from 0.65 to 0.93 (Heymsfield et al. 1995).The aims of our study were: (1) to estimate body composition in a large group of AN patients who were all in a starvation state; (2) to test the concurrent v...