Naslov
Three Days of Intermittent Fasting: Repeated- Sprint Performance Decreased by Vertical-Stiffness Impairment

Autori
Cherif, Anissa ; Meeusen, Romain ; Farooq, Abdulaziz ; Ryu, Joong ; Fenneni, Mohamed Amine ; Nikolovski, Zoran ; Elshafie, Sittana ; Chamari, Karim ; Roelands, Bart

Izvornik
International journal of sports physiology and performance (1555-0265) 12 (2017), 3; 287-294

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Mechanical output variables ; Biochemical parameters ; RSA-Repeated-sprints ability ; Glyconeogenesis ; Anaerobic exercise

Sažetak
Purpose: To examine the effects of 3 days of intermittent fasting (3d-IF: abstaining from eating/drinking from dawn to sunset) on physical performance and metabolic responses to repeated- sprints (RS). Methods: Twenty-one active males performed an RS-test [2 sets: 5×5-second maximal- sprints with 25 seconds of recovery between sprints and 3 minutes of recovery between sets on an instrumented treadmill] in two conditions: counter-balanced fed/control session (CS) and fasting session (FS assessed on the 3rd day of IF ; sessions: 4pm to 6pm, 7 days in-between). Biomechanical and biochemical markers were assessed pre- and post-exercise. Results: Significant main effects of IF were observed for sprints: maximal-speed (P=0.016), mean-speed (P=0.015), maximal-power (P=0.035), mean-power (P=0.049), vertical stiffness (P=0.032), and vertical center of mass displacement (P=0.047). Sprint speed and vertical stiffness decreased during the first and second sprints of set-2 (P=0.030). Post-exercise insulin decreased in CS (P=0.023) but not in FS (P=0.230). Free-fatty acid levels were higher in FS than that of CS at pre- (P<0.001) and at post-exercise (P=0.009). HDL- cholesterol was higher at post-exercise in FS (1.32±0.22-mmol.l-1) compared with that of CS (1.26±0.21-mmol.l-1, P=0.039). The triglyceride concentration was decreased in FS (P<0.05) compared with that of CS. Conclusion: The findings were that 3d-IF impaired speed and power through a decrease in vertical stiffness during the initial runs of the second set. The findings of the present study confirmed the benefits of 3d-IF: improved HDL-C and TG profiles while maintaining TC and LDL-C levels. Moreover, improving muscle power might be a key factor to retain a higher vertical stiffness and to partly counteract the negative effects of intermittent fasting. FS showed beneficial changes in biochemical marker levels from an overall health point of view.

Izvorni jezik
Engleski

Znanstvena područja
Kineziologija

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