No reserve in isokinetic cycling power at intolerance during ramp incremental exercise in endurance-trained men
| Autor: | Alan P. Benson, Harry B. Rossiter, Daniel T. Cannon, Lindsey A. Wylde, Carrie Ferguson |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Male
medicine.medical_specialty Anaerobic Threshold Physiology Population Electromyography Incremental exercise Young Adult 03 medical and health sciences 0302 clinical medicine Physical medicine and rehabilitation Physiology (medical) medicine Humans education Mathematics education.field_of_study Exercise Tolerance Muscle fatigue medicine.diagnostic_test VO2 max 030229 sport sciences Bicycling Power (physics) Muscle Fatigue Exercise Test Physical Endurance Female Cycling Anaerobic exercise 030217 neurology & neurosurgery Muscle Contraction Physical Conditioning Human |
| Zdroj: | Journal of Applied Physiology. 120:70-77 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.00662.2015 |
| Popis: | During whole body exercise in health, maximal oxygen uptake (V̇o2max) is typically attained at or immediately before the limit of tolerance (LoT). At the V̇o2max and LoT of incremental exercise, a fundamental, but unresolved, question is whether maximal evocable power can be increased above the task requirement, i.e., whether there is a “power reserve” at the LoT. Using an instantaneous switch from cadence-independent (hyperbolic) to isokinetic cycle ergometry, we determined maximal evocable power at the limit of ramp-incremental exercise. We hypothesized that in endurance-trained men at LoT, maximal (4 s) isokinetic power would not differ from the power required by the task. Baseline isokinetic power at 80 rpm (Piso; measured at the pedals) and summed integrated EMG from five leg muscles (ΣiEMG) were measured in 12 endurance-trained men (V̇o2max = 4.2 ± 1.0 l/min). Participants then completed a ramp incremental exercise test (20-25 W/min), with instantaneous measurement of Piso and ΣiEMG at the LoT. Piso decreased from 788 ± 103 W at baseline to 391 ± 72 W at LoT, which was not different from the required ramp-incremental flywheel power (352 ± 58 W; P > 0.05). At LoT, the relative reduction in Piso was greater than the relative reduction in the isokinetic ΣiEMG (50 ± 9 vs. 63 ± 10% of baseline; P < 0.05). During maximal ramp incremental exercise in endurance-trained men, maximum voluntary power is not different from the power required by the task and is consequent to both central and peripheral limitations in evocable power. The absence of a power reserve suggests both the perceptual and physiological limits of maximum voluntary power production are not widely dissociated at LoT in this population. |
| Databáze: | OpenAIRE |
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