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Normobaric hypoxia increases the growth hormone response to maximal resistance exercise in trained men
Filopoulos, Dean Cormack, Stuart J. Whyte, Douglas G.
Filopoulos, Dean
Cormack, Stuart J.
Whyte, Douglas G.
Abstract
This study examined the effect of hypoxia on growth hormone (GH) release during an acute bout of high-intensity, low-volume resistance exercise. Using a single-blinded, randomised crossover design, 16 resistance-trained males completed two resistance exercise sessions in normobaric hypoxia (HYP; inspiratory oxygen fraction, (FiO2) 0.12, arterial oxygen saturation (SpO2) 82 ± 2%) and normoxia (NOR; FiO2 0.21, SpO2 98 ± 0%). Each session consisted of five sets of three repetitions of 45° leg press and bench press at 85% of one repetition maximum. Heart rate, SpO2, and electromyographic activity (EMG) of the vastus lateralis muscle were measured throughout the protocol. Serum lactate and GH levels were determined pre-exposure, and at 5, 15, 30 and 60 min post-exercise. Differences in mean and integrated EMG between HYP and NOR treatments were unclear. However, there was an important increase in the peak levels and area under the curve of both lactate (HYP 5.8 ± 1.8 v NOR 3.9 ± 1.1 mmol.L−1 and HYP 138.7 ± 33.1 v NOR 105.8 ± 20.8 min.mmol.L−1) and GH (HYP 4.4 ± 3.1 v NOR 2.1 ± 2.5 ng.mL−1 and HYP 117.7 ± 86.9 v NOR 72.9 ± 85.3 min.ng.mL−1) in response to HYP. These results suggest that performing high-intensity resistance exercise in a hypoxic environment may provide a beneficial endocrine response without compromising the neuromuscular activation required for maximal strength development.
Keywords
bench press, electromyography, intermittent hypoxia, leg press, resistance exercise
Date
2017
Type
Journal article
Journal
European Journal of Sport Science
Book
Volume
17
Issue
7
Page Range
821-829
Article Number
ACU Department
School of Behavioural and Health Sciences
Faculty of Health Sciences
Faculty of Health Sciences
Relation URI
Source URL
Event URL
Open Access Status
License
File Access
Controlled