The effects of intensity and type of resistance training on muscle force generation capacity immediately- and 6 hours post-training

Introduction: The assessment of muscle force generation capacity (MFGC) is effective in determining muscular fatigability following resistance training and its association to prevalence with injuries. Subsequently, the purpose of the current study was to examine the intensity and type of resistance exercises on MFGC immediately- and 6 hours post-training. Methodology: Male participants (n = 12) performed high intensity whole body (HW), low intensity whole body (LW) and high intensity lower body only (HL) sessions in random order across three sessions. Exercises for HW and LW sessions were performed in the order of inclined leg-press, bench press and flat bench rows whereas the HL session solely consisted of inclined leg-press. The upper body and lower body exercises were performed with 4 and 6 sets, respectively. Exercises for HW and HL sessions were performed with 6 reps and 3 minutes rest between each set whereas exercises for the LW session were performed with 20 reps with 1.5 minutes rest between each set. MFGC of the right knee extensors were assessed prior to, immediately- and 6 hours following each of the resistance training session with an isometric dynamometer. A two-way (session × time) Friedman test was used to determine differences in MFGC. Results: Peak and average forces were significantly greater during pre- compared to immediately post-LW session (P 0.05), between pre-, immediately- and 6 hours following HW (P > 0.05) and between LW, HL and HW for immediately- and 6 hours following training (P > 0.05). Discussion and conclusion: A significant reduction in MFGC immediately following LW session indicates that a systemic effect was induced, exemplifying greater muscular fatigue compared to post-HW session. Similarly, a significant reduction in MFGC following HL session was found despite comparable MFGC between pre- and immediately post-HW session. These discrepancies in results may be because upper-body exercises were performed after leg-press causing a 30-minute window between the leg-press and the MFGC assessment for HW session. Subsequently, such findings indicate that physical activity may be performed immediately following high intensity- and 6 hours following high volume low intensity resistance training sessions constructed specifically for the current study with minimal risks of injuries