The purpose of the present study was to assess diurnal variations in selected physical variables before and during Ramadan fasting. The physical variables (speed, speed endurance, agility and power) were documented around the clock at five 4-hourly intervals before Ramadan began and on the twenty-third day of Ramadan (daytime fasting). Ten healthy nonsmoking male handball players volunteers were included in the study after routine clinical and laboratory examinations. These subjects were selected from Department of Physical Education and Sports Sciences, Annamalai University. Their ages averaged 27 ± 1.9 years. Time series were analysed with repeated measures ANOVA which revealed that there was a statistically significant changes as a result of Ramadan fasting among experimental days and times on speed, speed endurance, agility and power. Experimental day and time interaction showed that during Ramadan, compared with control period, time related variations of speed, speed endurance, agility and power changed significantly. To evaluate rhythmicity, the single cosinor method was used. Cosinor analysis clearly shows the shift in acrophase obtained from the subjects before to the 23rd day of Ramadan fasting. Ramadan induces day time changes in speed, speed endurance, agility and power.
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