Changes in plasma volume and baroreflex function following resistance exercise

Ploutz, L. L.; Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

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NASA NTRS · 20050000445

Changes in plasma volume and baroreflex function following resistance exercise

Ploutz, L. L.·Tatro, D. L.·Dudley, G. A.·Convertino, V. A.

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Abstract

The dynamics of change in plasma volume (PV) and baroreflex responses have been reported over 24 h immediately following maximal cycle exercise. The purpose of this study was to determine if PV and baroreflex showed similar changes for 24 h after resistance exercise. Eight men were studied on 2 test days, 1 week apart. On 1 day, per cent change (% delta) in PV was estimated at 0,3, and 6 h after resistance exercise using haematocrit and haemoglobin. Baseline PV was measured 24 h after exercise using Evans blue dye. The carotid baroreceptor-cardiac reflex response was measured before, and 3, 6, 9, 12, and 24 h post-exercise. Each subject performed six sets of the bench press and leg press with 10 repetitions per set with a load that induced failure within each set. On a control day, the protocol was used without exercise. Plasma volume did not change during the control day. There was a 20% decrease in PV immediately post-exercise; the recovery of the PV was rapid and complete within 3 h. PV was 20% greater 24 h post-exercise than on the control day. There were no differences in any of the baroreflex measurements. Therefore, it is suggested that PV shifts may occur without altering baroreflex sensitivity.

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NASA Program Space Physiology and Countermeasures NASA Discipline Number 14-10 NASA Center KSC NASA Discipline Cardiopulmonary Exertion/physiology Pressoreceptors/physiology Plasma Volume/physiology Reflex/physiology Male Adult Human Support, U.S. Gov't, Non-P.H.S

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Ploutz, L. L., Tatro, D. L., Dudley, G. A., Convertino, V. A.. 1993-07-01. Changes in plasma volume and baroreflex function following resistance exercise. https://ntrs.nasa.gov/citations/20050000445

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