Author(s)

Riki Ogasawara, Jeremy P. Loenneke, Robert S. Thiebaud, Takashi Abe

Department of Health and Exercise Science, University of Oklahoma, Norman, USA.
Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Japan; College of Sport and Health Science, Ritsumeikan University of Tokyo, Kusatsu, Japan.
Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Japan；Department of Health, Exercise Science, & Recreation Management, University of Mississippi, Oxford, USA.

The purpose of this study was to determine whether the training responses observed with low-load resistance exercise to volitional fatigue translates into significant muscle hypertrophy, and compare that response to high-load resistance training. Nine previously untrained men (aged 25 [SD 3] years at the beginning of the study, standing height 1.73 [SD 0.07] m, body mass 68.9 [SD 8.1] kg) completed 6-week of high load-resistance training (HL-RT) (75% of one repeti-tion maximal [1RM], 3-sets, 3x/wk) followed by 12 months of detraining. Following this, subjects completed 6 weeks of low load-resistance training (LL-RT) to volitional fatigue (30% 1 RM, 4 sets, 3x/wk). Increases (p < 0.05) in magnetic resonance imaging-measured triceps brachii and pectorals major muscle cross-sectional areas were similar for both HL-RT (11.9% and 17.6%, respectively) and LL-RT (9.8% and 21.1%, respectively). In addition, both groups increased (p < 0.05) 1RM and maximal elbow extension strength following training; however, the percent increases in 1RM (8.6% vs. 21.0%) and elbow extension strength (6.5% vs. 13.9%) were significantly (p < 0.05) lower with LL-RT. Both protocols elicited similar increases in muscle cross-sectional area, however differences were observed in strength. An explanation of the smaller relative increases in strength may be due to the fact that detraining after HL-RT did not cause strength values to return to baseline levels thereby producing smaller changes in strength. In addition, the results may also suggest that the consistent practice of lifting a heavy load is necessary to maximize gains in muscular strength of the trained movement. These results demonstrate that significant muscle hypertrophy can occur without high-load resistance training and suggests that the focus on percentage of external load as the important deciding factor on muscle hypertrophy is too simplistic and inappropriate.

Bench Press; Training Intensity; Muscle CSA; MRI; Strength

R. Ogasawara, J. Loenneke, R. Thiebaud and T. Abe, "Low-Load Bench Press Training to Fatigue Results in Muscle Hypertrophy Similar to High-Load Bench Press Training," International Journal of Clinical Medicine, Vol. 4 No. 2, 2013, pp. 114-121. doi: 10.4236/ijcm.2013.42022.