Purpose:
Resisted and assisted in-water training methods are often employed in swimming training but their effectiveness remains unsubstantiated for different strokes and age groups. The study aim was to quantify the effects of a 3-week combined assisted and resisted in-water training program on 50- and 100-m adolescent backstroke performance.

Methods:
In addition to regular swimming training, 9 (5 male, 4 female; age: 15.4 ± 1.7 years; 50-m backstroke FINA points: 346 ± 142) competitive backstroke swimmers performed a combined in-water machine-resisted and bungee-assisted training program 3 days/week with 3 resisted and 3 assisted 25-m sprints per session. Before and after the 3-week training, 50- and 100-m backstroke time trials were undertaken, with stroke rate, heart rate, and rating of perceived exertion collected.

Results:
There was a significant small improvement in 100-m backstroke times (3.4 ± 3.4% faster; ES = 0.27, p < 0.01), but only a trivial improvement in 50-m backstroke times (1.0 ± 3.1% faster; ES = 0.07, p = 0.19). Females had substantially greater improvements than males in both 50-m (2.4 ± 2.7% faster vs. –0.2 ± 3.2% slower) and 100-m (5.1 ± 2.6% faster vs. 2.0 ± 3.5% faster) backstroke time trials, but with the small sample size, this warrants further investigation.

Conclusions:
We demonstrated that adding a 3-week combined in-water resisted and assisted training was likely more beneficial for the longer 100-m distance; females seemed to benefit more than males.