Effect of Ramadan on the Diurnal Variation in Short‐Term High Power Output
- 1 January 2007
- journal article
- Published by Informa UK Limited in Chronobiology International
- Vol. 24 (5), 991-1007
- https://doi.org/10.1080/07420520701661914
Abstract
This study examined the effects of Ramadan fasting on anaerobic performances and their diurnal fluctuations. In a balanced and randomized study design, 12 subjects were measured for maximal power (P(max); force-velocity test), peak power (P(peak)), and mean power (P(mean)) with the Wingate test at 07:00, 17:00, and 21:00 h on four different occasions: one week before Ramadan (BR), the second week of Ramadan (SWR), the fourth week of Ramadan (ER), and two weeks after Ramadan (AR). There was an interval of 28 h between any two successive tests. Oral temperature was measured before each test. Under each condition, the results showed a time-of-day effect on oral temperature. Analysis of variance revealed a significant (Ramadanxtime-of-day of test) interaction effect on P(max). This variable improved significantly from morning to evening before Ramadan (1.1+/-0.2 W x kg(-1)), during the second week of Ramadan (0.6+/-0.2 W x kg(-1)), and two weeks after the end of Ramadan (0.9+/-0.2 W x kg(-1)). However, daily fluctuations disappeared during the fourth week of Ramadan. For P(peak) and P(mean), there was no significant Ramadan x test-time interaction. These variables improved significantly from morning to evening before Ramadan ([1+/-0.3 W x kg(-1)] for P(peak) and [1.7+/-1.6 W x kg(-1)] for P(mean)) and in the second week of Ramadan ([0.9+/-0.6 W x kg(-1)] for P(peak) and [1.7+/-1.5 W x kg(-1)] for P(mean)). However, they were not affected by time-of-day in the fourth week of Ramadan. Considering the effect of Ramadan on anaerobic performances, in comparison with before Ramadan, no significant difference was observed during Ramadan at 07:00 h. The variables were significantly lower in the second week of Ramadan and in the fourth week of Ramadan at 17:00 h and 21:00 h. P(mean) was not affected during the second week of Ramadan. In conclusion, the time-of-day effect on anaerobic power variables tends to disappear during Ramadan. In comparison with the period before Ramadan, anaerobic performances were unaffected in the morning but impaired in the evening during Ramadan.Keywords
This publication has 41 references indexed in Scilit:
- The influence of time of day and partial sleep loss on muscle strength in eumenorrheic femalesErgonomics, 2005
- Time‐of‐Day Effect on the Torque and Neuromuscular Properties of Dominant and Non‐Dominant Quadriceps FemorisChronobiology International, 2005
- Circadian Rhythms in Sports Performance—an UpdateChronobiology International, 2005
- Effects of Fasting on Endurance ExerciseSports Medicine, 1993
- Effects of protein supplementation during prolonged exercise at moderate altitude on performance and plasma amino acid patternEuropean Journal of Applied Physiology, 1993
- The Wingate Anaerobic TestSports Medicine, 1987
- Interet de l'agenda de sommeil pour l'etude des troubles de la vigilanceElectroencephalography and Clinical Neurophysiology, 1985
- Sleep, Performance and Mood After the Energy‐Expenditure Equivalent of 40 Hours of Sleep DeprivationPsychophysiology, 1980
- Influence of muscle temperature on maximal muscle strength and power output in human skeletal musclesActa Physiologica Scandinavica, 1979
- Diet, Muscle Glycogen and Physical PerformanceActa Physiologica Scandinavica, 1967