To evaluate the effect of Ramadan fasting on parameters of insulin resistance in trained athletes at rest and after aerobic exercise.
Nine male rugby players (age 19 ± 2 yr, height 1.78 ± 0.74 m) were tested 3 times: 1 week before observance of Ramadan (C), at the end of the first week (R1), and during the fourth week (R2). They performed a progressive cycle-ergometer test at each visit. Data collected at rest and at the end of aerobic exercise included simple anthropometry (body mass, body-mass index, body fat, fat-free mass), biochemical parameters (serum glucose, cholesterol, HDL cholesterol, triglycerides, creatinine, and serum proteins), and selected hormone concentrations (plasma insulin, leptin, and adiponectin).
Ramadan fasting was associated with a reduction of body mass and body fat (R2 vs. C, p < .01) without significant change in leptin or adiponectin levels.
Lipolysis might have occurred because of increased plasma triglycerides and HDL cholesterol concentrations.
Bouhlel is with the Superior Inst. of Sport and Physical Education, Gafsa, Tunisia. Denguezli, Zaouali, and Tabka are with the Physiology Laboratory, Ibn el Jazzar Faculty of Medicine, Sousse, Tunisia. Shephard is with the Faculty of Physical Education and Health, University of Toronto, Toronto, ON, Canada.