Force output reductions from the manipulation of blood flow and load in resistance trained individuals

Abstract

Previous research on force output reductions following various training methods have resulted in inconclusive suggestions regarding the prescription of both LL training and BFR training as alternatives to HL training in an elite sport setting. The studies are limited in their accuracy due to methodological differences including training volume, prescription of task failure, participant training history, and measurement techniques. It remains unclear whether these differences extend to resistance-trained individuals, and whether there are differences between the contributory mechanisms that affect force output reductions. The aim of this thesis was to observe differences in force output reductions in resistance trained individuals following various training protocols. The initial study was developed to examine the extent of force output reductions and the subsequent recovery following an acute bout of BFR training. This study used knee extension, leg curl and leg press with and without BFR at 50% of the individuals 1-RM. Results identified significant reductions in force output for both training conditions, and a complete recovery of force output by 24H. The force output reductions were concomitant with significant reductions in muscle contractility. The subsequent study was developed to explore acute differences in force output reductions between HL and LL resistance exercise performed to momentary task failure. Individuals were exposed to two training sessions at 50% 1-RM and >80% 1-RM with measurements collected before, immediately after and one hour following exercise. This study found greater reductions in force output following LL training than HL training, with a complete recovery of force output by 1H for both training groups. An interplay of muscle contractility and activation loss appeared to influence force output reductions between training loads in this study. The results of the studies indicate force output reductions are apparent in various training conditions and loads. In an acute setting, it appears muscle contractility is the primary contributory mechanism underpinning the force output reductions.

Date of Award	2020
Original language	English
Awarding Institution	Western Sydney University
Supervisor	Paul Marshall (Supervisor)