Effect of Ramadan fasting on feelings, dietary intake, rating of perceived exertion and repeated high intensity short-term maximal performance

• Published in: Chronobiology International Vol. 36; no. 1; pp. 1 - 10
• Main Authors: Boukhris, Omar, Hsouna, Hsen, Chtourou, Lassaad, Abdesalem, Raouf, BenSalem, Sahar, Tahri, Nabil, Trabelsi, Khaled, Stannard, Stephen R., Chtourou, Hamdi
• Format: Report
• Language: English
• Published: Taylor & Francis 02.01.2019
• Subjects: exercise; fatigue; feelings; Ramadan; sleep; sport
• ISSN: 0742-0528; 1525-6073
• DOI: 10.1080/07420528.2018.1513943

The present study was designed to investigate the effect of Ramadan fasting on feelings, dietary intake, rating of perceived exertion (RPE) and repeated high-intensity short-term maximal performance. Thirteen physically active men (age: 21.2 ± 2.9 years, height: 175.6 ± 5.6 cm, body-mass: 72.4 ± 8.6 kg) performed a 5-m shuttle run test (6 × 30-s + 35-s of recovery in-between) during five experimental periods: fifteen days before Ramadan (BR), the first ten days of Ramadan (FR), the last ten days of Ramadan (ER), ten days after Ramadan (AR10) and 20 days after Ramadan (AR20). The study was carried out in Tunisia during the 2016 Ramadan month. During the 5-m shuttle run test, higher distance (HD), total distance (TD) and fatigue index (FI) were recorded. RPE was determined after a 5-min warm-up and after each repetition of the 5-m shuttle run test (the mean RPE score during the test was calculated). Moreover, a feelings scale (FS) was used after the warm-up and after the end of the 5-m shuttle run test. During the five experimental periods, dietary intake was assessed. The results showed that HD, TD and FI during the 5-m shuttle run test were not affected by Ramadan observance (p > 0.05). Likewise, FS scores recorded after the warm-up and the 5-m shuttle run test were not affected by Ramadan fasting (p > 0.05). However, mean RPE scores during the 5-m shuttle run test were significantly lower at ER (4.06 UA), AR10 (3.86 UA) and AR20 (3.71 UA) in comparison to BR (4.51 UA) (p < 0.05). The results showed also that Ramadan fasting has no adverse effect on energy intake, protein (g and %), fat (g and %) and carbohydrate (g). However, the fractional contribution of carbohydrate was significantly higher AR10 than FR (53.1% vs. 45.8%) and ER (53.1% vs. 46.5%) and AR20 than FR (5.92% vs. 45.8%) (p < 0.05). In conclusion, Ramadan fasting has no adverse effect on feelings, dietary intake, and short-term maximal performance. However, the RPE during repeated high intensity short-term maximal exercise was reduced AR20 in comparison to ER. Abbreviations: AR: After Ramadan; AR10: Ten days after Ramadan; AR20: Twenty days after Ramadan; BR: Fifteen days before Ramadan; ER: Last ten days of Ramadan; FI: Fatigue index; FR: First ten days of Ramadan; FS: Feelings scale; HD: Higher distance; PSQI: The Pittsburgh Sleep Quality Index; RPE: Rating of Perceived Exertion Scale; TD: Total distance