The Impact of Volume-Matched, Heavy vs Moderate Weight Resistance Training on Inflammation and Muscular Damage

Abstract

BACKGROUND: It is well documented that resistance exercise training improves muscular strength and hypertrophy. Heavy loads greater than 65% of 1 repetition maximum (1RM) are typically required for optimal induction of muscular hypertrophy. Heavy loads tend to induce greater muscular damage and repair, resulting in enhanced muscular hypertrophy. However, there is little information comparing intensities of hypertrophy inducing resistance loads on muscular damage and inflammatory response. The purpose of this study was to compare heavy vs moderate hypertrophying loads on markers of post exercise muscular inflammation and damage. METHODS: 11 resistance-trained, college-aged males were recruited for this study. Participants were asked to complete 3 data collection sessions, each 1 week apart. During session 1, a baseline venous blood draw was collected, followed by evaluation of 1RM barbell squat. With sessions 2 and 3, participant performed volume-matched barbell squats at 2 different intensities using a counter-balanced design: 5 sets of 5 reps at 85% (High) or 3 sets of 11 reps at 67% (Low). Blood draws were taken 1 hour post-exercise for sessions 2 and 3. Plasma was isolated and evaluated via ELISA assay. RESULTS: There were no significant changes (p<.05) in plasma C-Reactive Protein (CRP) for any of the 3 time points (358.78+180.32, 454.52+520.68, 322.01+188.02 ng/mL for Baseline, High, Low, respectively). Myoglobin, a marker of muscular damage, is awaiting analysis. CONCLUSIONS: Current results suggest that the utilized volume of hypertrophying resistance training, at either load, does not induce detectable changes in inflammation in the plasma.