Heart Rate Determined Rest Intervals In Hypertrophy-type Resistance Training

Abstract

Inter-set rest is an important aspect of hypertrophy training. Validity of traditional, time-based, rest protocols are complicated by individual differences in recovery capacity and energy production. Efficacy of inter-set rest in hypertrophy-type resistance training may therefore be improved when standardized to a marker of physiological recovery status (HR). PURPOSE: To examine whether inter-set rest intervals based on time or heart rate differed in hypertrophy-type resistance training based upon the total number of bench press repetitions. METHODS: Thirty-four trained college men performed bench press exercise for ≥ 8 reps at 60% 1-RM for as many sets as possible until volitional fatigue on two separate occasions and in a randomized cross-over design. The participants rested for 60 sec between sets under the time-based protocol and for a variable time period under the HR-based protocol. The HR-based protocol was determined by the time needed to return to baseline levels. Total bench press repetitions were counted for all successful repetitions performed throughout the protocol. Paired t-tests were used to determine differences between rest protocols. Alpha levels were set at P<. 05. RESULTS: The participants were younger (22.7±3.7 yr-1) trained (4.0±1.2 d·week-1) men from Springfield College. A statistically significant difference was found in total bench press reps between rest protocols (P= <.001) with the HR protocol yielding a greater number of reps (55.1±16.6 vs. 39.5±16.6 reps) than the time protocol. The HR protocol also exhibited lesser performance declines compared to the time protocol (P=.01), but did require more rest (+14.6 ±17.3 sec) between sets as the training volume increased. CONCLUSION: We found a HR-determined rest protocol yielded a significantly greater number of total bench press repetitions among college men performing a hypertrophy-type resistance training protocol. Our findings are novel and provide evidence that HR-based rest protocols may be better suited for the determination of rest-period duration in hypertrophy-type resistance training programs.