Tensiomyographic Characteristics of Rectus Femoris after a Single Bout of Intense Exercise

Problem statement: It is not well known how local fatigue can impair the contractile properties of skeletal muscle, so the aim of this study was to determine the Tensiomyographic (TMG) characteristics of Rectus Femoris (RF) after a single bout of intense exercise. Approach: Twelve healthy male volunteers (mean±SEM; age, 24.16±0.62 years, height 172.02±1.21 cm, body mass 71.84±2.19 kg, BMI 24.42±0.70 kg m^-1) were recruited. Results: In session 1, a graded exercise test on cycle ergometer was performed in order to determine subject’s maximal oxygen uptake (VO_2max) and power at this key point (pVO_2max). In a second testing session, TMG rest values were assessed and then all subjects carried out 2 min of cycling at pVO_2max after which TMG analysis was applied again. The results showed subject’s VO_2max values of 53.44±2.67 ml kg^-1 min^-1, reaching a mean pVO_2max of 270.83±8.61 W. Maximal radial displacement (Dm) and time from the onset of electrical stimulus to 10% of Dm (Td) were significantly lower at post-test (from 7.577.57±0.92-4.37±0.67 mm; p = 0.01, for Dm and from 25.25±0.57-22.44±0.89 ms; p≤0.05, for Td). Conclusion/Recommendations: It can be concluded that a brief and intense exercise consisting in 2 min of cycling at PVO_2max provokes a reduction in contractile properties of RF considering TMG parameters such as Dm and Td. More studies are needed to clarify the role of muscle fatigue on temporal TMG parameters.