Effect of Eight Week's Dryland Strength Training on Adolescent Backstroke and Freestyle Performance: A Randomized Controlled Trial

Abstract

OBJECTIVES Swimmers undertake dryland training to improve power and maximise propulsion. Our purpose was to improve strength and quantify transfer to adolescent sprint backstroke and freestyle performances. METHODS Twenty-eight male competitive swimmers participated (age: 12.6±2.6 years; height 156.4±13.4 cm; mass 49.8±15.0 Kg; 50 m freestyle best time 45.0±8.5 s) and were randomized to either dryland strength plus swimming (DS) or a swimming only control group (CONT). The 8 week dryland programme (3 days/week) consisted of 8–10 exercises per session (22 exercises in total) with predominantly 1–2 sets of ~10–20 repetitions. Pre, mid and post 8 weeks training, a strength test battery (countermovement jump, pronated chin ups, isometric forearm and back extension) and 25 m pool testing of backstroke and freestyle was undertaken. RESULTS DS had greater strength improvements across the test battery (13–167%; ES, 0.51–1.84) than CONT (8-120%; ES, 0.35–2.0) with p<0.05 for 6 of 8 measures. For 50 and 100 m freestyle, DS had greater percentage improvement (DS, 4.8±1.6 and 3.7±1.6%, ES, 0.20 and 0.16; CONT, 2.7±0.9 and 1.6±0.8%, ES, 0.16 and 0.13, p<0.01). There was no between group statistically significant change in backstroke percentage improvement, however both groups displayed small magnitudes of improvements in 50 m and trivial improvements over the 100 m distance (DS, 4.4±2.3 and 1.6±0.5%, ES, 0.29 and 0.08; CONT, 3.6±2.5 and 1.3±0.5%, ES, 0.26, 0.08). CONCLUSIONS Over 8 weeks, adding 90 min dryland training / week to ~7 hour/week swim schedule further improved freestyle ~2.1% and backstroke ~0.5% more than swim training alone.

Keywords

• dryland
• power
• swimming
• time trial
• transfer