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The influence of Metabo‐ and Baroreceptors on Postexercise Heat Loss
Author(s) -
Paull Gabrielle,
McGinn Ryan,
Fujii Naoto,
Dervis Sheila,
Haqani Baies,
Flouris Andreas,
Kenny Glen
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.993.6
Subject(s) - baroreceptor , forearm , medicine , isometric exercise , heart rate , baroreflex , cardiology , blood pressure , anesthesia , surgery
We studied the relative and separate contribution of metabo‐ and baroreflex activity to heat loss during postexercise recovery. Seven males (21 ± 2 years) performed 15 min of running (90% heart rate max) in the heat (35°C). During the 60 min postexercise period, four 1‐min bouts of isometric handgrip exercise (IHG) were followed by 2 min of forearm ischemia (toactivate metaboreceptors, OCC), each separated by 15 min. This was repeated on separate days during a normal seated recovery (CON) and during the application of lower body positive (LBPP, +40 mmHg) or negative (LBNP, ‐20 mmHg) pressure starting at 13 min of recovery. Forearm sweat rate and cutaneous vascular conductance (CVC) were measured continuously. For all conditions CVC returned to pre‐dynamic exercise resting levels at 45 min of recovery ( P > 0.05) whereas sweating remained elevated for the duration of recovery ( P < 0.05). Relative to pre‐IHG resting CVC was reduced during IHG at 15 min of recovery and subsequently returned to pre‐IHG levels during OCC in CON only. No effect of IHG on CVC was observed for LBPP or LBNP. However LBNP caused an OCC‐induced decrease in CVC from pre‐IHG levels at 15 min of recovery only ( P < 0.05). Sweating increased during IHG and remained elevated at similar levels during OCC for all conditions in the final 30 min of recovery ( P < 0.05). We show that metaboreceptors influence CVC during the early stages of recovery which is modulated to a certain extent by baroreceptor activity. In contrast, sweating is influenced by metaboreceptor activation in the mid‐to‐late stages of recovery independent of changes in baroreceptor activity. Support: Natural Sciences and Engineering Research of Canada.