Accession Number : ADA524537


Title :   Hypohydration Reduces Vertical Ground Reaction Impulse But Not Jump Height


Descriptive Note : Journal article


Corporate Author : ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION


Personal Author(s) : Cheuvront, Samuel N ; Kenefick, Robert W ; Ely, Brett R ; Harman, Everett A ; Catellani, John W ; Frykman, Peter N ; Nindl, Bradley C ; Sawka, Michael N


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a524537.pdf


Report Date : Jan 2010


Pagination or Media Count : 9


Abstract : This study examined vertical jump performance using a force platform and weighted vest to determine why hypohydration (4% body mass) does not improve jump height. Jump height and other measures of functional performance from a force platform were determined for 15 healthy and active males when euhydrated (EUH), hypohydrated (HYP) and hypohydrated while wearing a weighted vest (HYPv) adjusted to precisely match water mass losses. HYP produced a significant loss of body mass [- 3.2 +/- 0.5 kg (- 3.8 +/- 0.6%); P0.05], but body mass in HYPv was not different from EUH. There were no differences in absolute or relative peak force or power among trials. Jump height was not different between EUH (0.380 +/- 0.048 m) and HYP (0.384 +/- 0.050 m), but was 4% lower (P0.05) in HYPv (0.365 +/- 0.52 m) than EUH due to a lower jump velocity between HYPv and EUH only (P0.05). However, vertical ground reaction impulse (VGRI) was reduced in both HYP and HYPv (2-3%) compared with EUH (P0.05). This study demonstrates that the failure to improve jump height when hypohydrated can be explained by offsetting reductions in both VGRI and body mass.


Descriptors :   *PERFORMANCE(HUMAN) , FUNCTIONAL ANALYSIS , DEHYDRATION , WATER MASSES , HEIGHT , REPRINTS , MALES


Subject Categories : Anatomy and Physiology
      Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE