Impact of dehydration on a full body resistance exercise protocol

This study examined effects of dehydration on a full body resistance exercise workout. Ten males completed two trials: heat exposed (with 100% fluid replacement) (HE) and dehydration (similar to 3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (similar to 39A degrees C). Following HE and DEHY, participants performed three sets to failure (using predetermined 12 repetition maximum) of bench press, lat pull down, overhead press, barbell curl, triceps press, and leg press with a 2-min recovery between each set and 2 min between exercises. A paired t test showed total repetitions (all sets combined) were significantly lower for DEHY: (144.1 +/- A 26.6 repetitions) versus HE: (169.4 +/- A 29.1 repetitions). ANOVAs showed significantly lower repetitions (similar to 1-2 repetitions on average) per exercise for DEHY versus HE (all exercises). Pre-set rate of perceived exertion (RPE) and pre-set heart rate (HR) were significantly higher [similar to 0.6-1.1 units on average in triceps press, leg press, and approached significance in lat pull down (P = 0.14) and similar to 6-13 b min(-1) on average in bench press, lat pull down, triceps press, and approached significance for overhead press (P = 0.10)] in DEHY versus HE. Session RPE difference approached significance (DEHY: 8.6 +/- A 1.9, HE: 7.4 +/- A 2.3) (P = 0.12). Recovery HR was significantly higher for DEHY (116 +/- A 15 b min(-1)) versus HE (105 +/- A 13 b min(-1)). Dehydration (similar to 3%) impaired resistance exercise performance, decreased repetitions, increased perceived exertion, and hindered HR recovery. Results highlight the importance of adequate hydration during full body resistance exercise sessions.