Respiratory Uptake and Depuration Kinetics of Perfluorooctanesulfonate (PFOS) in a Marine Sandworm Species.
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ABSTRACT:
SUBMITTER: Sakurai T
PROVIDER: S-EPMC5519661 | biostudies-other | 2017 Aug
REPOSITORIES: biostudies-other
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Project description:PurposeWe tested the hypothesis that the described increase in oxygen uptake ([Formula: see text])-plateau incidence following a heavy-severe prior exercise is caused by a steeper increase in [Formula: see text] and muscle fiber activation in the submaximal intensity domain.MethodsTwenty-one male participants performed a standard ramp test, a [Formula: see text] verification bout, an unprimed ramp test with an individualized ramp slope and a primed ramp test with the same ramp slope, which was preceded by an intensive exercise at 50% of the difference between gas exchange threshold and maximum workload. Muscle fiber activation was recorded from vastus lateralis, vastus medialis, and gastrocnemius medialis using a surface electromyography (EMG) device in a subgroup of 11 participants. Linear regression analyses were used to calculate the [Formula: see text]-([Formula: see text]) and EMG-(?RMS/?P) ramp test kinetics.ResultsTwenty out of the 21 participants confirmed their [Formula: see text] in the verification bout. The [Formula: see text]-plateau incidence in these participants did not differ between the unprimed (n?=?8) and primed (n?=?7) ramp test (p?=?0.500). The [Formula: see text] was lower in the primed compared to the unprimed ramp test (9.40?±?0.66 vs. 10.31?±?0.67 ml min-1 W-1, p?<?0.001), whereas the ?RMS/?P did not differ between the ramp tests (0.62?±?0.15 vs. 0.66?±?0.14% W-1; p?=?0.744).ConclusionThese findings do not support previous studies, which reported an increase in [Formula: see text]-plateau incidence as well as steeper increases in [Formula: see text] and muscle fiber activation in the submaximal intensity domain following a heavy-severe prior exercise.
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