Impact of dehydration on a full body resistance exercise protocol

Abstract

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 (approximately 3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (approximately 39 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 +/- 26.6 repetitions) versus HE: (169.4 +/- 29.1 repetitions). ANOVAs showed significantly lower repetitions (approximately 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 [approximately 0.6-1.1 units on average in triceps press, leg press, and approached significance in lat pull down (P = 0.14) and approximately 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 +/- 1.9, HE: 7.4 +/- 2.3) (P = 0.12). Recovery HR was significantly higher for DEHY (116 +/- 15 b min(-1)) versus HE (105 +/- 13 b min(-1)). Dehydration (approximately 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.

Effect of Hypohydration on Muscle Endurance, Strength, Anaerobic Power and Capacity and Vertical Jumping Ability: A Meta-Analysis

“…Of these, 28 [7, 8, 11-14, 17-20, 24, 25, 30-45] met all of the inclusion criteria, thereby producing a total of 85 individual studies and weighted mean treatment effects to investigate the impact of hypohydration on upper (6/85) and lower (10/85) body muscle endurance, upper (14/85) and lower (25/85) body muscle strength, muscle anaerobic power (9/85) and capacity (9/85), and vertical jumping ability (12/85). A total of 20 research manuscripts produced more than one weighted mean treatment effect, with Hayes and Morse [25] producing ten, Ftaiti et al [34] producing two, Wilson et al [45] two, Cheuvront et al [17] two, Bigard et al [8] two, Bijlani and Sharma [30] two, Bosco et al [31] two, Bosco et al [32] six, Caterisano et al [33] three, Greiwe et al [35] four, Gutierrez et al [36] six, Jacobs [37] six, Jones et al [13] two, Judelson et al [11] six, Kraft et al [38] two, Montain et al [39] two, Naharudin and Yusof [40] six, Periard et al [41] four, Viitasalo et al [44] four, and Webster et al [12] four effect estimates. The work of Naharudin and Yusof [40] and Caterisano et al [33] contained three different groups of participants, while that of Gutierrez et al [36] contained two different groups of participants.…”

“…2.4.2). Of all 28 manuscripts, only seven made it clear that participants voided their bladders prior to BW measurements before and after the dehydration protocol [8,11,20,25,38,42,43]. No study mentioned controlling for fecal loss during the experiments.…”

“…Of these, 129 were considered trained [11, 12, 18, 24, 32-34, 36, 37, 40-42, 44] and 155 untrained [7,8,13,14,17,19,20,25,30,31,33,35,38,39,43,45]. Their physical characteristics are presented in Table 2.…”

Sprinting: Optimizing Dietary Intake

“…Furthermore, sprint performance over distances of 50-400 m remain stable despite an acute reduction in body mass equivalent to 2.0-2.5% (Watson et al, 2005). Despite this, there is evidence to suggest longer duration activities undertaken by sprint athletes such as resistance training are impaired by hypohydration (Kraft et al, 2010). On the weight of this evidence, track sprinting performance does not appear to be infl uenced by a state of hypohydration within the range of 2-3% (see Chapter 15).…”

Strength and Power Events

“…Additionally, some strength and power athletes may consider that their sporting events do not last long enough to induce or suffer ill effects from hypohydration. However, it appears that resistance exercise performance (Kraft et al, 2010) and mean and total peak cycling power (Jones et al, 2008) are reduced with modest hypohydration (3% of body mass). Thus, strength and power athletes should be encouraged to begin training and competition properly hydrated to prevent performance decrements (see Chapter 15).…”