Dissociation between exercise intensity thresholds: Mechanistic insights from supine exercise
| Autor: | Shunsaku Koga, Dai Okushima, Richie P. Goulding, Tze-Huan Lei, David C. Poole, Thomas J. Barstow, Narihiko Kondo, Simon Marwood |
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| Přispěvatelé: | Physiology, AMS - Musculoskeletal Health |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Adult
Male Time Factors Supine position Adolescent Physiology Timeresolved near-infrared spectroscopy Deoxy- + total (hemoglobin + myoglobin) Respiratory compensation Dissociation (chemistry) Quadriceps Muscle Hemoglobins Young Adult chemistry.chemical_compound Oxygen Consumption Nuclear magnetic resonance Physiology (medical) Supine Position Humans Exercise Heme Supine exercise Spectroscopy Near-Infrared Electromyography Myoglobin Pulmonary Gas Exchange Exercise intensity thresholds Healthy Volunteers chemistry Exercise intensity Respiratory compensation point Energy Metabolism Biomarkers Muscle Contraction |
| Zdroj: | American Journal of Physiology-Regulatory Integrative and Comparative Physiology, 321(5), R712-R722. American Physiological Society Goulding, R P, Marwood, S, Lei, T H, Okushima, D, Poole, D C, Barstow, T J, Kondo, N & Koga, S 2021, ' Dissociation between exercise intensity thresholds : Mechanistic insights from supine exercise ', American Journal of Physiology-Regulatory Integrative and Comparative Physiology, vol. 321, no. 5, pp. R712-R722 . https://doi.org/10.1152/ajpregu.00096.2021 |
| ISSN: | 0363-6119 |
| Popis: | This study tested the hypothesis that the respiratory compensation point (RCP) and breakpoint in deoxygenated [heme] [deoxy[heme]BP, assessed via near-infrared spectroscopy (NIRS)] during ramp incremental exercise would occur at the same metabolic rate in the upright (U) and supine (S) body positions. Eleven healthy men completed ramp incremental exercise tests in U and S. Gas exchange was measured breath-by-breath and time-resolved-NIRS was used to measure deoxy[heme] in the vastus lateralis (VL) and rectus femoris (RF). RCP (S: 2.56 ± 0.39, U: 2.86 ± 0.40 L·min−1, P = 0.02) differed from deoxy[heme]BP in the VL in U (3.10 ± 0.44 L·min−1, P = 0.002), but was not different in S in the VL (2.70 ± 0.50 L·min−1, P = 0.15). RCP was not different from the deoxy[heme]BP in the RF for either position (S: 2.34 ± 0.48 L·min−1, U: 2.76 ± 0.53 L·min−1, P > 0.05). However, the deoxy[heme]BP differed between muscles in both positions ( P < 0.05), and changes in deoxy[heme]BP did not relate to ΔRCP between positions (VL: r = 0.55, P = 0.080, RF: r = 0.26, P = 0.44). The deoxy[heme]BP was consistently preceded by a breakpoint in total[heme], and was, in turn, itself preceded by a breakpoint in muscle surface electromyography (EMG). RCP and the deoxy[heme]BP can be dissociated across muscles and different body positions and, therefore, do not represent the same underlying physiological phenomenon. The deoxy[heme]BP may, however, be mechanistically related to breakpoints in total[heme] and muscle activity. |
| Databáze: | OpenAIRE |
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