Postactivation potentiation: upper body force development changes after maximal force intervention.
The neuromuscular phenomenon postactivation potentiation can possibly be used to increase the rate of force development (RFD) and maximal power (Pmax). Various intervention protocols have been examined with varying results. Maximal intervention protocols using 1 repetition maximum (1RM) have been examined in earlier studies in the lower body with positive results, but no studies have investigated maximal protocols on the upper body. Using maximal protocols would furthermore eliminate the uncertainties when expressing intensity as either numbers of RM or percentage of 1RM and hence emphasize standardization. Thus, the aim of this study was to examine the force development characteristics in the upper body after a maximal bench-press intervention. Eight strength trained male athletes performed an intervention protocol consisting of 5x 1RM in the bench press. Pre and post the intervention, a test consisting of either an isometric maximal voluntary contraction or a bench throw was completed to measure isometric RFD (iRFD) or Pmax, respectively. Statistical significance was accepted at p </= 0.05. After the intervention, a significant decrease in iRFD was observed. No difference was found in Pmax from pre to post. These results conflict with earlier results found in the lower body using the exact same intervention. It could be speculated if different activation levels in the upper body vs. the lower body could explain the conflicting results. In conclusion, to elicit postactivation potentiation in the upper body, an intervention of maximal intensity is not warranted. The practical applications of these results are that coaches and athletes should be careful to implement maximal resistance to elicit a potentiation until further studies have been conducted in this area.
Farup
Jean
J
Department of Sport Science, University of Aarhus, Arhus, Denmark. jean@sport.au.dk
Sørensen
Henrik
H
D000328:Adult; D056352:Athletes; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*; D055815:Young Adult