Low-Frequency Fatigue as an Indicator of Eccentric Exercise-Induced Muscle Injury: The Role of Vitamin E

Abstract

This study investigates whether vitamin E can attenuate eccentric exercise-induced soleus muscle injury as indicated by the amelioration of in situ isometric force decline following a low-frequency fatigue protocol (stimulation at 4 Hz for 5 min) and the ability of the muscle to recover 3 min after the termination of the fatigue protocol. Adult male Wistar rats were divided into vitamin E-supplemented or placebo-supplemented groups studied at rest, immediately post-exercise or 48 h post-exercise. Daily dl-α-tocopheryl acetate intraperitoneal injections of 100 mg/kg body mass for 5 consecutive days prior to exercise doubled its plasma levels. Fatigue index and recovery index expressed as a percentage of the initial tension. FI at 0 h post- and 48 h post-exercise respectively was 88% ± 4.2% and 89% ± 6.8% in the vitamin E groups versus 76% ± 3% and 80% ± 11% in the placebo groups. RI was 99% ± 3.4% and 100% ± 6% in the vitamin E groups versus 82% ± 3.1% and 84% ± 5.9% in the placebo groups. Complementally to the traditionally recorded maximal force, low-frequency fatigue measures may be beneficial for assessing injury-induced decrease in muscle functionality.

The rat adequately reflects human responses to exercise in blood biochemical profile: a comparative study

“…The major advantage of rats over mice is the greater tissue sample size and the larger blood volume that allows measurement of a complete set of blood biomarkers. Rats have been used to address diverse research questions in the exercise physiology field including physical performance (Veskoukis et al 2008;Booth and Laye 2009), metabolism (Nikolaidis et al 2004;Brooks 2009), fatigue (Allen et al 2008;Kyparos et al 2012), muscle atrophy (Fitts et al 2001;Kyparos et al 2005), gene expression, and signaling pathways (Nikolaidis et al 2003;R€ ockl et al 2008).…”

Histological characteristics of exercise‐induced skeletal muscle remodelling

“…Previous studies had demonstrated that temporary skeletal muscle injury can be induced in rats by horizontal treadmill exercise at a speed of 15-16 m/min for a cumulative period of approximately 90 min or until exhaustion. [23][24][25] Paola et al found that, in rats, horizontal treadmill exercise of 15-45 min per day for 2-4 weeks at a speed of 30-45 cm/s can accelerate functional recovery following traumatic muscular injury. 15,26 18 m/min for 5 min (rest interval 2 min and 18 times), can induce skeletal muscle injury and contraction excitation-coupling failure in rats.…”