Anthropometric and physiologic profiles of female professional yoga practitioners and energy expenditure during asanas execution.

AIM: The present study aimed to: 1) define the anthropometric and physiological profiles of female professional yoga practitioner compared to that of other athletes; 2) evaluate the energy expenditure (EE) during a yoga session. METHODS: The percentage fat mass (FM%) and fat free mass (FFM%), the maximal aerobic power (VO2max), the maximal voluntary contraction (MVC) of knee extensor muscles and the maximal anaerobic alactacid power (Wmax) were assessed in a group of yoga practitioners (Yo), long distance runners (LDR), sprinters (Spr), karate practitioners (Ka) and sedentary control subjects (Con). EE was evaluated in Yo during a yoga session (execution of a sequence of six yoga postures, called asanas). RESULTS: FM% was significantly higher in Con (24.2±2.6%) than in other groups (18±1.9%, pooled data, P<0.05). FFM% did not differ among groups. VO2max was higher in LDR (55.6±1.8 mL min-1 kg-1) compared to other groups (41.7±3 mL min-1 kg-1, pooled data, P<0.05). MVC and Wmax were higher in Yo, Spr and Ka than in LDR and Con (P<0.05). In Yo, EE increased in comparison to baseline, during Sirasana execution only (+59%, P<0.05). CONCLUSION: These data suggest that chronic yoga practice is associated with 1) values of FM%, FFM%, MVC and Wmax similar to those induced by sports requiring high degree of force and power of lower limb muscles, with maximal aerobic performance similar to control subjects; 2) low EE during most asanas execution.

Physical activity ratios for various commonly performed sedentary and physical activities in obese adolescents.

The physical activity ratio (PAR) values are commonly used to convert subjects' physical activity recalls into estimates of daily energy expenditure (DEE). A PAR is defined as the ratio between energy expenditure corresponding to a sedentary or a physical activity (kJ/min) and basal metabolic rate [(BMR) kJ/min]. The objective of the present study was to determine the PAR for different sedentary and physical activities in obese adolescents. Thirty-three obese adolescents [mean body mass index: 35.1 kg/m2; 40.3 % fat mass] aged 11 to 17 yr participated in this study. BMR was assessed by indirect calorimetry after an overnight fast by means of an open-circuit, indirect computerised calorimetry with a rigid, transparent, ventilated canopy. Energy expenditures corresponding to various sedentary and physical activities in free-living conditions were determined using a portable metabolic unit, and body composition by bioelectrical impedance analysis (BIA). The PAR of each activity was obtained by dividing the assessed energy expenditure by BMR. In this study, the PAR of various sedentary and physical activities did not vary significantly with sex, age, and body mass. Thus, the data for boys and girls were combined and the PAR for 27 sedentary and physical activities were determined. The PAR values can be applied to determine the mean DEE (kJ) using the specific equation considering BMR (kJ/min), PAR, and duration (min) of each activity performed by the subject during the 24 h. This information will be useful to health-care professionals because estimation of DEE in obese adolescents is necessary in order to prescribe an adequate dietary therapy to induce a desired level of energy deficit.

Transdermal iontophoretic delivery of methylphenidate HCl in vitro.

Methylphenidate is prescribed orally for Attention Deficit Disorder in children and adults, and for narcolepsy patients. Methylphenidate has a short plasma half-life (1-2 h) and thus needs to be frequently administered for effective therapy. Such therapy has limitations in terms of patient compliance, particularly in young children. For such reasons, the development of a transdermal dosage form of methylphenidate may be useful. This study was undertaken to evaluate the passive and electrically assisted transport (iontophoresis) of methylphenidate from aqueous methylphenidate hydrochloride solutions across excised human skin. A maximum flux of 12.0 micrograms/(cm2 h) of protonated methylphenidate was estimated from the passive transport data at pH 3.5. Iontophoresis significantly enhanced protonated methylphenidate transport as compared with passive delivery. From the present experiments, the efficiency of iontophoretic delivery of methylphenidate was approximately 700 micrograms/(mA h). Based on in vitro skin flux data, the daily dose of 15-40 mg methylphenidate can be achieved using a current density of 0.5 mA/cm2 and a minimum transport area of 2-5 cm2 for 24-h application, or an area of 4-10 cm2 for 12-h (daytime) application. From methylphenidate skin flux values, methylphenidate mobility of 2.2 x 10(-4) cm2/(V s) was estimated, which compares reasonably with its free solution mobility of 6.6 x 10(-4) cm2/(V s).