Supplementary low-intensity aerobic training improves aerobic capacity and does not affect psychomotor performance in professional female ballet dancers.

We investigated whether 6-week low-intensity aerobic training program used as a supplement to regular dance practice might improve both the aerobic capacity and psychomotor performance in female ballet dancers. To assess their maximal oxygen uptake (VO2max) and anaerobic threshold (AT), the dancers performed a standard graded bicycle ergometer exercise test until volitional exhaustion prior to and after the supplementary training. At both these occasions, the psychomotor performance (assessed as multiple choice reaction time) and number of correct responses to audio-visual stimuli was assessed at rest and immediately after cessation of maximal intensity exercise. The supplementary low-intensity exercise training increased VO2max and markedly shifted AT toward higher absolute workload. Immediately after completion of the graded exercise to volitional exhaustion, the ballerinas' psychomotor performance remained at the pre-exercise (resting) level. Neither the resting nor the maximal multiple choice reaction time and accuracy of responses were affected by the supplementary aerobic training. The results of this study indicate that addition of low-intensity aerobic training to regular dance practice increases aerobic capacity of ballerinas with no loss of speed and accuracy of their psychomotor reaction.

Long-term consumption of a carbohydrate-restricted diet does not induce deleterious metabolic effects.

Carbohydrate (CHO)-restricted diets have been recommended for weight loss and to prevent obesity, but their long-term effects have not been fully elucidated. This study was designed to evaluate the effect of long-term (>1 year) consumption of a low-CHO high-fat diet ("The optimal diet," developed by Dr Kwasniewski referenced herein) on lipid profile, glycemic control, and cardiovascular disease risk factors in healthy subjects. Of 31 "optimal" dieters enrolled in the study (17 women and 14 men, aged 51.7+/-16.6 years), 22 declared adherence to the diet for more than 3 years. Average energy intake and principal nutrients consumed were assessed from 6-day dietary records provided by the participants. In most dieters, concentrations of beta-hydroxybutyrate, free fatty acids, total cholesterol, and low-density lipoprotein cholesterol exceeded the upper limits of the reference ranges for nonstarved subjects. The metabolic profiles of most subjects were positive for several indicators, including relatively low concentrations of triacylglycerols, high levels of high-density lipoprotein cholesterol (HDL-C), and normal ratios of low-density lipoprotein cholesterol/HDL-C and total cholesterol/HDL-C. In most subjects, plasma concentrations of glucose, insulin, glucagon, cortisol, homocysteine, glycerol, and C-reactive protein were within reference ranges. Notably, in all but one subject, the homeostasis model assessment index of insulin resistance remained below the threshold for diagnosis of insulin resistance. These results indicate that long-term (>1 year) compliance with a low-CHO high-fat "optimal diet" does not induce deleterious metabolic effects and does not increase the risk for cardiovascular disease, as evidenced by maintenance of adequate glycemic control and relatively low values for conventional cardiovascular risk factors.