We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Effects of pedal frequency on estimated muscle microvascular O2 extraction.
- Authors
Ferreira, Leonardo F; Lutjemeier, Barbara J; Townsend, Dana K; Barstow, Thomas J
- Abstract
An increase in muscle contraction frequency could limit muscle blood flow QM compromising the matching of QM and muscle oxygen uptake VO2M. This study examined the effects of pedal cadence on skeletal muscle oxygenation at low, moderate and peak exercise. Nine healthy subjects [24.7+/-6.3 years (SD)] performed incremental cycling exercise at 60 and 100 rpm. Pulmonary VO2(VO2P) was measured breath-by-breath and vastus lateralis oxygenation was determined by near-infrared spectroscopy (NIRS). The deoxyhemoglobin signal ([HHb]) from NIRS was used to estimate microvascular O2 extraction (i.e., [HHb] proportional, variant VO2M/QM). The VO2P and [HHb] for low, moderate and at peak exercise were determined. The VO2P at 60 rpm (low=0.64+/-0.13, moderate=2.03+/-0.38 and peak=3.39+/-0.84 l/min) were lower (P<0.01) than at 100 rpm (1.29+/-0.23, 2.14+/-0.39 and 3.54+/-0.88 l/min, respectively). There was a progressive increase in [HHb] from low to peak exercise. However, there was no significant difference (ANOVA, P=0.94) for the 60 (in microM, low=24.0+/-9.5, moderate=30.5+/-13.8 and peak=36.7+/-16.5) and 100 contractions/min (in microM, low=25.7+/-11.6, moderate=32.1+/-14.0 and peak=35.4+/-16.5). We conclude that vastus lateralis O2 extraction was similar at 60 and 100 cpm, suggesting that the VO2M/QM in the microcirculation was not altered and, presumably, no impairment of QM occurred with the increase in pedal frequency.
- Subjects
BLOOD circulation; OXYGEN metabolism; COMPARATIVE studies; EXERCISE; EXERCISE tests; HEMOGLOBINS; RESEARCH methodology; MEDICAL cooperation; MICROCIRCULATION; MUSCLE contraction; NEAR infrared spectroscopy; RESEARCH; EVALUATION research; OXYGEN consumption; SKELETAL muscle; PHYSIOLOGY
- Publication
European Journal of Applied Physiology, 2006, Vol 96, Issue 4, p558
- ISSN
1439-6319
- Publication type
journal article
- DOI
10.1007/s00421-005-0107-3