High intensity interval training induces the expression of Myostatin and Follistatin isoforms in rat muscle: differential effects on fast and slow twitch skeletal muscles

The aim of this study was to investigate the rate of Myostatin (MSTN) and Follistatin (FLST) gene expression in fast and slow twitch muscles in response to 8 weeks of high intensity interval training (HIIT). To this end, 12 male 8-week old Wistar rats were randomly classified into two groups of exercise (n=6) and control (n=6). Exercise group performed a progressive HIIT protocol, five times weekly for 8 weeks using alternating sprint running for 30 min/session that divided into three 4min bouts (35-50m/min speed, >90% VO2 max) separated by a 2min active recovery period (30-50% VO2 max). Gene expression levels for MSTN and FLST in Soleus (SOL) and Extensor digitorum longus (EDL) muscles were measured by real-time RT-PCR. MSTN mRNA levels has slightly (7%); yet significantly (p