Vätskebalansens effekt på styrka, kraft och prestation vid styrketräning

[King Grub]

Although many studies have attempted to examine the effect of hypohydration on strength, power, and high-intensity endurance, few have successfully isolated changes in total body water from other variables that alter performance (e.g., increased core temperature), and none have documented the influence of hypohydration on an isotonic, multiset, multirepetition exercise bout typical of resistance exercise training. Further, no investigations document the effect of hypohydration on the ability of the central nervous system to stimulate the musculature, despite numerous scientists suggesting this possibility. The purposes of this study were to examine the isolated effect of hydration state on 1) strength, power, and the performance of acute resistance exercise, and 2) central activation ratio (CAR).

Seven healthy resistance-trained males (age = 23 +/- 4 yr, body mass = 87.8 +/- 6.8 kg, body fat = 11.5 +/- 5.2%) completed three resistance exercise bouts in different hydration states: euhydrated (EU), hypohydrated by approximately 2.5% body mass (HY25), and hypohydrated by approximately 5.0% body mass (HY50). Investigators manipulated hydration status via exercise-heat stress and controlled fluid intake 1 d preceding testing. RESULTS:: Body mass decreased 2.4 +/- 0.4 and 4.8 +/- 0.4% during HY25 and HY50, respectively. No significant differences existed among trials in vertical jump height, peak lower-body power (assessed via jump squat), or peak lower-body force (assessed via isometric back squat). CAR tended to decrease as hypohydration increased (EU = 95.6 +/- 4.9%, HY25 = 94.0 +/- 3.1%, HY50 = 92.5 +/- 5.1%; P = 0.075, etap = 0.41). When evaluated as a function of the percentage of total work completed during a six-set back squat protocol, hypohydration significantly decreased resistance exercise performance during sets 2-3 and 2-5 for HY25 and HY50, respectively.

These data indicate that hypohydration attenuates resistance exercise performance; the role of central drive as the causative mechanism driving these responses merits further research.

Med Sci Sports Exerc. 2007 Oct;39(10):1817-24. Effect of hydration state on strength, power, and resistance exercise performance.

[Sniggel]

Nu har jag rört ihop begreppen...
hypo=under
hyper=över
Eller är det tvärtom?

Om det är som jag tror så antar jag att artikeln säger, "glöm inte bort att dricka vatten" :-p

[TobiasNP]

japp, korrekt

http://englishplus.com/grammar/00000221.htm

[z_bumbi]

Intressant att få det i siffror.

[King Grub]

It is well established that resistance exercise can damage muscle tissue, but the combined effects of hypohydration and resistance exercise on muscle damage are unclear. Two common circulating markers of muscle damage, myoglobin (Mb) and creatine kinase (CK) may be attenuated by fluid ingestion post-exercise. The purpose of this study was to examine the combined effect of resistance exercise and hydration state on muscle damage. Seven healthy resistance-trained males (age = 23 +/- 4 years; body mass = 87.8 +/- 6.8 kg; body fat = 11.5 +/- 5.2%) completed 3 identical resistance exercise bouts (6 sets of up to 10 repetitions of the back squat) in different hydration states: euhydrated (HY0), hypohydrated ~2.5% body mass (HY2.5), and hypohydrated ~5.0% body mass (HY5). Subjects achieved desired hydration states via controlled water deprivation, exercise-heat stress, and fluid intake. Both Mb and CK were measured during euhydrated rest (PRE). Mb was also measured immediately post-exercise, 1 hour (+1H) and 2 hours (+2H) post-exercise; CK was measured at 24 and 48 hours post-exercise. Body mass decreased 0.2 +/- 0.4%, 2.4 +/- 0.4%, and 4.8 +/- 0.4% during HY0, HY2.5, and HY5, respectively. Mb concentrations increased significantly (effect size >/=1, p < 0.05) from PRE (2.6 +/- 1.1, 3.5 +/- 2.8, and 3.2 +/- 1.6 nmol.L) to +1H (5.3 +/- 3.4, 6.8 +/- 3.2, and 7.6 +/- 2.8 nmol.L), and +2H (5.5 +/- 3.8, 6.2 +/- 3.0, and 7.2 +/- 3.0 nmol.L) for HY0, HY2.5, and HY5, respectively, but were not significantly different between trials. CK concentrations remained within the normal resting range at all time points. Thus, hypohydration did not enhance muscle damage following the resistance exercise challenge. Despite these results, athletes are encouraged to commence exercise in a euhydrated state to maximize endogenous hormonal, mechanical, and metabolic benefits.

J Strength Cond Res. 2008 Aug 14. Effects of Hydration State and Resistance Exercise on Markers of Muscle Damage.