Effects of Ramadan intermittent fasting on middle distance running performance in well trained runners

Jeanick Brisswalter (1) , Ezzedine Bouhlel (2) , Jean Marie Falola (3) , Jean-Marc Vallier (1) , Christophe Hausswirth (4)

1 LAMHESS - Laboratoire Motricité Humaine Expertise Sport Santé
2 Université de Sousse
3 UAC - Université d’Abomey-Calavi = University of Abomey Calavi
4 INSEP - Institut national du sport, de l'expertise et de la performance

Objective: To assess whether Ramadan intermittent fasting (RIF) affects 5000m running performance and physiological parameters classically associated with middle distance performance. Design: Eighteen subjects (age 23.6±2.9 yr, body mass 64 ± 2.3 kg) divided in two experimental groups (Ramadan fasting (n = 9 vs. control, n= 9) participated in two experimental sessions, one before RIF and the other the last week of fasting. Setting: For each session subjects completed four tests in the same order: a maximal running test, a maximal voluntary contraction (MVC) of knee extensor, two rectangular submaximal exercises on treadmill of 6 min duration at an intensity corresponding to the first ventilatory threshold (VT1) and a running performance test (5000m). Participants: 18 well-trained middle distance runners Main Outcome Measurements: Maximal oxygen consumption, maximal voluntary contraction, running performance, running efficiency submaximal VO2 kinetics parameters (basal VO2 : VO2b, time constant : τ, and amplitude : A1) and anthropometric parameters were recorded or calculated. Results: At the end of Ramadan fasting a decrease in maximal voluntary contraction was observed, (-3,2%, p< .00001, Eta2: 0.80), associated with an increase in time constant of oxygen kinetics (+51%, p< .00007, Eta2: 0.72) and a decrease in performance (-5%, p< .0007, Eta2: 0.51). No effect was observed on running efficiency or maximal aerobic power. Conclusions: These results suggest that Ramadan changes in muscular performance and oxygen kinetics could affect performance during middle distance events and need to be considered to choose training protocols during RIF.

Mots clés: anaerobic performance; running efficiency; muscular strength; VO2 kinetics

Domaines: Physiologie du sport

Jeanick Brisswalter, Ezzedine Bouhlel, Jean Marie Falola, Jean-Marc Vallier, Christophe Hausswirth. Effects of Ramadan intermittent fasting on middle distance running performance in well trained runners. Clinical Journal of Sport Medicine, 2011, 21 (5), pp.422-427. ⟨10.1097/JSM.0b013e3182293891⟩. ⟨hal-01813464⟩