Effect of Resistance Training to Muscle Failure vs. Volitional Interruption at High- and Low-Intensities on Muscle Mass and Strength

Abstract

Nóbrega, SR, Ugrinowitsch, C, Pintanel, L, Barcelos, C, and Libardi, CA. Effect of resistance training to muscle failure vs. volitional interruption at high- and low-intensities on muscle mass and strength. J Strength Cond Res 32(1): 162-169, 2018-The purpose of this study was to investigate the effects of resistance training (RT) at high- and low-intensities performed to muscle failure or volitional interruption on muscle strength, cross-sectional area (CSA), pennation angle (PA), and muscle activation. Thirty-two untrained men participated in the study. Each leg was allocated in 1 of 4 unilateral RT protocols: RT to failure at high and low intensities, and RT to volitional interruption (repetitions performed to the point in which participants voluntarily interrupted the exercise) at high (HIRT-V) and low (LIRT-V) intensities. Muscle strength (1 repetition maximum [1RM]), CSA, PA, and muscle activation by amplitude of the electromyography (EMG) signal were assessed before (Pre), after 6 (6W), and 12 (12W) weeks. 1RM increased similarly after 6W (range: 15.8-18.9%, effective size [ES]: 0.41-0.58) and 12W (range: 25.6-33.6%, ES: 0.64-0.98) for all protocols. All protocols were similarly effective in increasing CSA after 6W (range: 3.0-4.6%, ES: 0.10-0.24) and 12W (range: 6.1-7.5%, ES: 0.22-0.26). PA increased after 6W (∼3.5) and 12W (∼9%; main time effect, p < 0.0001), with no differences between protocols. EMG values were significantly higher for the high-intensity protocols at all times (main intensity effect, p < 0.0001). In conclusion, both HIRT-V and LIRT-V are equally effective in increasing muscle mass, strength, and PA when compared with RT performed to muscle failure.

Concurrent training performed with and without repetitions to failure in older men: A randomized clinical trial

“…Therefore, future studies with a larger number of individuals may be necessary to confirm the present findings. Despite this limitation, in agreement with our results, Nóbrega et al submitted young men to knee extension ST for 12 weeks, and they observed similar improvements in maximal strength and muscular hypertrophy among groups performing repetitions to failure and not to failure, independent of ST intensity and even without volume compensation. Taken together, these findings indicate that performing repetitions leading to concentric failure is not critical for inducing increases in strength and muscle size when sufficient ST intensity is achieved.…”

“…After the intervention period, the improvements found in the lower limb maximal dynamic and isometric strength (PT iso ) were in agreement with gains observed in previous studies investigating CT in older men . Regarding the use of repetitions to failure or not to failure, our findings are in accordance with those of other studies that carried out similar comparisons over shorter training periods (from 6 to 16 weeks) in young and older individuals . In a previous study performed in our laboratory, Da Silva et al showed that 12 weeks of CT induced marked adaptations in the maximal dynamic strength and isometric peak torque of the lower limbs, regardless of whether repetitions to failure or greater ST volumes were used.…”

“…In addition, Cadore et al have shown that CT using repetitions to failure and not to failure induced similar enhancements in sit‐to‐stand ability, muscle power output, VO 2peak , body composition, and serum HDL in older men. However, these studies verified adaptations following 12 weeks of training, while studies involving young populations investigated this issue across training periods ranging from 6 to 16 weeks . Thus, it remains unclear if the same findings (ie, similar adaptations to maximal and submaximal repetitions) would be observed over longer training interventions (ie, 20 weeks).…”

“…These findings suggest that repetitions to failure may not be critical for promoting significant changes in muscle function. Moreover, it seems that ST with maximal repetitions per set does not induce further muscle size gains in young subjects . Nevertheless, most of the above‐mentioned studies have investigated this issue in young adults, and to the best of the authors’ knowledge, only two studies have focused on the effects of ST using repetitions to failure or non‐failure in older men .…”

“…[3][4][5] Regarding strength training (ST), performing exercises leading to concentric failure (repetition maximum-RM) has received considerable attention from researchers; however, the additional benefits that this type of training can promote are still questionable, especially in the context of CT. [6][7][8] It have been suggested that performing repetitions to failure would optimize muscular adaptations, 9 but few studies have shown that this training strategy induces greater strength gains than the non-failure approach. 10,11 Indeed, several investigations have observed that repetitions to failure produce similar changes in maximal strength, 7,[12][13][14][15] maximal neuromuscular activity, 7,15,16 and muscle power output 8 compared with the non-failure approach. These findings suggest that repetitions to failure may not be critical for promoting significant changes in muscle function.…”