Abstract
This study investigated the effects of Ramadan on activity patterns, body composition
and muscle function. 11 moderately active Muslim males were screened 1 month and 1
week before, in the last week of, and 1 month after Ramadan. Activity patterns were
assessed during 72 h using a tri-axial accelerometer, body composition was evaluated
via bio-electrical impedance and muscle function during maximal isometric contractions
with EMG recordings. Data showed a modification of the activity pattern during Ramadan
with a higher level of activity from 02:00 to 05:00 h (29±26, 364±323 and 27±22 steps.h − 1 before, during and after Ramadan, respectively, P<0.05). However, total daily energy
expenditure was similar during all testing periods (506±156, 542±219 and 545±207 Kcal.day − 1, respectively), partly explaining the lack of influence of Ramadan on body mass (70.9±11,
70.0±9 and 70.8±9 Kg, respectively) and composition (all P>0.05). Maximal force, associated
electrical activity and neuromuscular efficiency (torque/EMG ratio) were maintained
during Ramadan (torque: 254.6±30 N.m − 1, Neuromuscular efficiency: 1.0±0.4 a.u.) to levels observed before (244.3±26 N.m,
1.1±0.5 a.u.) and after the holy month (252.5±31 N.m, 1.1±0.5 a.u.). In summary, our
data suggest that the influence of Ramadan should be considered as a modification
in the distribution of activity times during the day.
Key words
intermittent fasting - circadian rhythms - diurnal activity - performance