Eccentron (BTE Technologies, Inc.) training

Hydroworks aquatic training

Both arms/conditions use varying forms of exercise as the intervention.

Participants will perform three maximal counter movement vertical jumps on a force platform. Participants will be instructed to stand on the platform with their feet shoulder width apart with their hands on their hips. Participants will be instructed to quickly lower themselves to a comfortable depth then immediately jump as high as possible while landing with their legs relatively straight (Crane et al., 2020). A successful countermovement jump attempt will be counted if the participant lands on the platform with both feet and does not take a step before jumping (Palmer et al., 2014). A 1-minute rest period will be provided between each jump attempt. Participants will be asked to perform three practice jumps with their hands placed on hips. Following the completion of practice jumps, participants will perform 3 trials of countermovement jumping on land and 3 trials while immersed in water at waist-depth.

Participants will perform three maximal-effort depth jumps from a height of 0.4 meters onto a force plate. Participants will be instructed to step straight off of the box without lowering themselves prior to falling, then to land and quickly jump as high as they can with minimal ground contact time. A successful jump attempt requires landing on the force plate with both feet both from the drop as well as from the rebound jump. A 1-minute rest period will be provided between each jump attempt.

Participants will be tested on a custom-made isometric mid-thigh pull (IMTP) device. This device consists of a force plate set onto an aluminum plate to which a bar is attached via chains, which are adjustable for height. The subject will be fitted with an over-the-shoulder vest which will be secured to straps fixed to the force plate. The straps will be adjusted so that the participant's knee angle is set within a range of 125-145°, and the hip angle in a range of 140-150°, as has been suggested to be optimal (Comfort et al., 2019). Participants will be instructed to stand on the plate with feet shoulder width apart, and then to move to a point where the slack is all out of the straps. To initiate the pull, participants will be instructed to drive their feet through the floor as hard and as fast as they can, while keeping their feet and upper body in position, starting on the signal, and not performing a countermovement prior to the pull.

local muscle soreness will be assessed throughout the duration of the intervention period using a Wagner force algometer.

During the course of the training period, soreness levels will be assessed using a visual analog scale (VAS), in accordance with our previous procedures (Crane et al., 2020). The VAS will be administered at baseline (prior to the first training session) and for five consecutive days following the first training session of the first experimental week and then on three nonconsecutive, non-training days per week for the remaining six weeks (Crane et al., 2020).