Does Warming Up With Wearable Resistance Influence Internal and External Training Load in National Level Soccer Players?

Abstract

Adding wearable resistance (WR) to training results in superior performance compared with unloaded conditions. However, it is unclear if adding WR during warm-up influences training load (TL) in the subsequent session. The aim of this research was to track TL in soccer players during the transition from late preseason to early in-season and examine whether adding WR to the lower leg during a warm-up influenced TL measures during warm-ups and on-field training sessions after WR was removed. The addition of WR worn on the lower legs during an on-field warm-up would lead to decreases in relatively high-intensity external TL metrics, such as distance covered >6.11 m∙s-1 and acceleration and deceleration >/<3 m∙s-2 and increases in internal TL during the warm-up, yet would have little effect on the subsequent training session when WR was removed. Matched-pair randomized design. Level 3. A total of 28 soccer players were allocated to either a WR training (WRT = 14) or unloaded (control [CON] = 14) group. Both groups performed the same warm-up and on-field training for 8 weeks, with the WRT group wearing 200 g to 600 g loads on their lower leg during the warm-up. External TL was measured via global positioning system data and internal TL was assessed using session rating of perceived exertion (sRPE × time per session). No statistically significant between-group differences (P ≥ 0.05) were identified for any TL measurement during either warm-ups or training sessions. Lower leg WR resulted in trivial to moderate effects for all external TL metrics (-16.9% to 2.40%; d = -0.61 to 0.14) and sRPE (-0.33%; d = -0.03) during the warm-up and trivial to small effects on all external TL metrics (-8.95% to -0.36%; d = -0.45 to -0.30) and sRPE (3.39%; d = 0.33) during training sessions. Warming up with lower leg WR negatively affects neither the quality and quantity of the warm-up nor the subsequent training session once WR is removed. Using WR on the lower leg during on-field warm-ups may be a means to "microdose" strength training while not unduly increasing TL. However, further research is needed to determine the influence of WR on strength qualities.