The Optimal Load for Maximal Power Production During Upper-Body Resistance Exercises: A Meta-Analysis.

BACKGROUND: External mechanical power is considered to be one of the most important characteristics with regard to sport performance.

OBJECTIVE: The purpose of this meta-analysis was to examine the effect of load on kinetic variables such as mean and peak power during bench press and bench press throw, thus integrating the findings of various studies to provide the strength and conditioning professional with more reliable evidence upon which to base their program design.

METHODS: A search of electronic databases (MEDLINE, PubMed, Google Scholar, and Web of Science) was conducted to identify all publications up to 31 October 2015. Hedges' g (95 % confidence interval) was estimated using a weighted random-effect model, due to the heterogeneity (I 2 ) of the studies. Egger's test was used to evaluate possible publication bias in the meta-analysis. A total of 11 studies with 434 subjects and 7680 effect sizes met the inclusion criterion and were included in the statistical analyses. Load in each study was labeled as one of three intensity zones: zone 1 represented an average intensity ranging from 0 to 30 % of one repetition maximum (1RM); zone 2 between 30 and 70 % of 1RM; and zone 3 ≥ 70 % of 1RM.

RESULTS: These results showed different optimal loads for each exercise examined. Moderate loads (from >30 to <70 % of 1RM) appear to provide the optimal load for peak power and mean power in the bench press exercise. Lighter loads (<30 % of 1RM) appear to provide the highest mean and highest peak power production in the bench press throw exercise. However, a substantial heterogeneity was detected I 2  > 75 %.

CONCLUSION: The current meta-analysis of published literature provides evidence for exercise-specific optimal power loading for upper body exercises.