An investigation of the concept of repeat power ability in repeated high intensity effort performance

  • Alexander Natera

Student thesis: Doctoral Thesis

Abstract

In the prescription and assessment of power emphasised resistance exercise, the use of low to moderate repetition schemes, between 1-6 repetitions, are most common. High repetition schemes ranging from 8 to 30 repetitions have also been used to assess and develop both maximal power output and the ability to maintain maximal power output across multiple repetitions. Repeat power ability (RPA) can be defined as the ability to maintain power output within small margins of decline during resistance training exercise. Whilst high volume power training (HVPT) is a training method utilising relatively high repetition schemes and volumes of power based exercises, in comparison to traditional power training.

Repeated high intensity efforts (RHIEs) are maximal intensity efforts performed in succession in team sports, a minimum of 3 efforts with < 21 s between efforts. RHIEs have been found to be critical for successful performance in many team sports. Although both aerobic and maximal intensity abilities are not associated with RHIEs, muscular endurance has been found to be related. Given that RHIEs are generally efforts requiring high force and rapid muscular efforts, RPA may be a physical quality that relates to RHIE performance.

The aims of this thesis were to review the current research on RPA and HVPT and to develop a reliable and valid assessment of RPA. This thesis also sought to define and further explain RPA and its association with other physical qualities including RHIE performance. This thesis further sought to understand and explain RPA by using a more novel analysis method of the entire force-time curve.

The first study (Chapter 1) reviewed the current literature on RPA and HVPT. The objectives of the systematic review were 1) to identify different HVPT protocols, 2) examine both the acute and chronic adaptations to different HVPT protocols, 3) identify different lower body RPA assessment protocols and highlight similarities, difference, and limitations between each protocol and 4) describe the reliability and validity of RPA assessments. Although there was limited research in the area, a range of HVPT protocols were reported, with HVPT found to be a method of training that can enhance RPA, RHIEs, anaerobic power and capacity and aerobic performance. There are a range of different RPA assessments found in the literature with several RPA assessments found to be reliable and valid.

The second study (Chapter 3) sought to identify the most reliable and valid ballistic RPA assessment and measurement indices. Two different RPA assessments were examined with twenty repetitions of loaded squat jumps (LSJ20) and twenty loaded countermovement jumps (LCMJ20) performed with a 30% 1RM half squat load. Average peak power output for both the LSJ20 and the LCMJ20 were found to be reliable (CV 2.5-3.8%; ICC = 0.94-0.96). The best metric to describe power output changes across the RPA assessment was the peak power output percent decrement score (CV = 4.9%; ICC = 0.85).

The third study (Chapter 4) sought to identify the underlying physical qualities that determine RPA and to establish the uniqueness or otherwise of RPA. A RHIE assessment was found to have a strong relationship with the LCMJ20 (r = 0.736; p < 0.05). Multiple linear regression could only explain 48.4% of the variance with the RHIE assessment the only covariate in the prediction model (Adjusted R2 = 0.484, F(1,8) = 9.43, p =0.015).

The final study (Chapter 5) sought to further investigate RPA by performing force-time curve analysis to identify differences across the LCMJ20 and identify differences in the force-time curve between participants with low and high RPA scores. Statistical parametric mapping one-way ANOVA found significantly lower propulsive forces across the LCMJ20 (p < 0.001).Participants with low RPA scores (better ability to maintain peak power output) had significantly higher forces during both the braking and propulsive phases than those with high RPA scores (p < 0.001).

In summary, the results of this thesis have increased our overall knowledge and understanding of RPA and its interaction with RHIEs. These findings will be relevant to strength and conditioning coaches and sport science practitioners wishing to gain a deeper understanding of the physical qualities of team sport athletes and to monitor training interventions more effectively.
Date of Award2024
Original languageEnglish
SupervisorJustin Keogh (Supervisor), Dale Chapman (Supervisor) & Neil Chapman (Supervisor)

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