Seasonal variation of alterations in exercise-induced body composition in obese Japanese women

Abstract

Although many investigations have been conducted to determine the effects of exercise and/or diet prescription, seasonal variations in weight loss have not been thoroughly investigated in Japan. The present investigation was undertaken to determine seasonal variations in body composition and anthropometric characteristics during a weight-loss program. One hundred and twenty-seven women [mean (SD) age 44.3 (11.7) years] participated in this study. The subjects were categorized into four groups based on the season in which the weight-loss program was begun: subjects who joined our exercise program in winter (group WE), subjects who joined in summer (group SE), and two control groups, one for winter and one for summer (group WC and group SC, respectively). The subjects of groups WE and SE completed a 3-month exercise and food-restriction program. Analyses of covariance revealed that the subjects of group WE seemed to have attained more desirable changes. This group showed a decrease in body mass (-1.9 (1.5) kg) and percent body fat (-4.6 (4.8)%), while an increase in fat-free mass (1.6 (3.2) kg) during the experimental period. Our data suggest that the better season for desirable weight loss in Japan is winter, compared to summer. These alterations may be attributable, at least in part, to the fact that Japanese people are generally acclimatized to a cold climate in this season. The mechanisms involved in our speculation have not been well validated, but it seems clear that a significant difference in dietary intake might have affected the results of this study.

Association between Physical Activity and Seasonal Variations in Metabolic and Vascular Function in Adults

“…Generally, exposure to cold temperatures increases the activity of brown adipose tissue and decreases body fat mass [46]. Winter is the best season for lipid metabolism and weight loss due to an increase in available metabolites [47]. Conversely, long exposure to comfortable temperatures can lead to a loss of brown adipose tissue and an increase in body fat [48].…”

Effect of maintaining supervised gym- and home-based exercises on the seasonal variations of metabolic outcomes in overweight and obese Japanese adults

“…Winter may be the best season for weight loss and glucose and lipid metabolism due to an increase in available metabolites, including ready mobilisation of fat. 14 However, exposure to low temperature induces various physiological responses by the sympathetic nervous system activity and hormones. 15 16 Low temperature increases blood glucose concentration [17][18][19][20] and arteriolar vasoconstriction.…”

Comment on “Differences in Ventilatory Threshold for Exercise Prescription in Outpatient Diabetic and Sarcopenic Obese Subjects”

“…In the methods, “Clinical Evaluation” it is stated that “All subjects were evaluated in the morning” without providing any further information for circadian effects (time of day) and seasonal period [ 2 ] control. To evaluate body composition, the authors use both DEXA and BIA without justifying this choice, that is, Why both?…”