January 1, 1991Journal of Applied Physiology
Effects of high-intensity cycle exercise on sympathoadrenal-medullary response patterns
Key result
Brief high-intensity cycle exercise at 36% maximal leg power significantly increased plasma peptide F immunoreactivity from a resting value of 0.18 to 0.43 pmol/ml (P<0.05).
Why the study?
Does high-intensity cycle exercise alter plasma proenkephalin peptide F immunoreactivity and catecholamines in healthy males?
Population
9 healthy males
Comparison
Maximal cycle exercise to exhaustion at four… vs Resting baseline values before exercise
Design
Other
Follow-up
15 minutes post-exercise
Authors
Discussion
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Implication
High-intensity exercise was associated with elevated peptide F in healthy males; hypothesis-generating for proenkephalin responses and requires prospective validation.
Key Points
- To determine the response patterns of plasma proenkephalin peptide F immunoreactivity, catecholamines, and blood lactate following exhaustive cycle exercise across multiple supramaximal intensities.
- Nine healthy males performed maximal cycle ergometer exercise to exhaustion at four supramaximal intensities (36%, 55%, 73%, and 100% of maximal leg power [MLP]) on separate days.
- Durations averaged 3.31 min (36% MLP), 0.781 min (55% MLP), 0.270 min (73% MLP), and 0.1 min (100% MLP), with all intensities exceeding individual peak oxygen uptake.
- Blood was sampled before, immediately after, and at 5 and 15 min post-exercise to measure plasma peptide F immunoreactivity, epinephrine, norepinephrine, and whole blood lactate.
- Plasma proenkephalin peptide F immunoreactivity increased significantly immediately after exercise only at 36% MLP, rising from a resting mean of 0.18 to 0.43 pmol/ml (P < 0.05).
- Plasma epinephrine significantly increased immediately post-exercise at 36% MLP (2.22 to 3.11 pmol/ml) and 55% MLP (1.67 to 2.98 pmol/ml), and at 15 min post-exercise at 100% MLP (1.92 to 3.88 pmol/ml; P < 0.05).
- Plasma norepinephrine increased significantly immediately post-exercise across all intensities (36%, 55%, 73%, and 100% MLP), remaining elevated at 5 min (36%, 55%, 73% MLP) and 15 min (36% MLP; P < 0.05).
Structured PICO
Does high-intensity cycle exercise alter plasma proenkephalin peptide F immunoreactivity and catecholamines in healthy males?
P
Population
9 healthy males undergoing maximal cycle exercise to exhaustion at four intensities.
I
Intervention
Maximal cycle exercise to exhaustion at four intensities (36, 55, 73, and 100% of maximal leg power) on separate days
C
Comparator
Resting baseline values before exercise
O
Outcome
Plasma proenkephalin peptide F immunoreactivity and catecholamines (epinephrine, norepinephrine) measured before, immediately after, and 5 and 15 min after exercisesurrogate
Main Result
Absolute Event Rate: 0.43% vs 0.18%
p-value: p=<0.05
Brief high-intensity exercise elicits differential response patterns of catecholamines and proenkephalin peptide F immunoreactivity in healthy males.
Cite This Study
Kraemer et al. (1991) studied Healthy (n=9). High-intensity cycle exercise vs. Resting values was evaluated on Plasma peptide F immunoreactivity immediately after exercise at 36% maximal leg power (p=<0.05). Brief high-intensity cycle exercise at 36% maximal leg power significantly increased plasma peptide F immunoreactivity from a resting value of 0.18 to 0.43 pmol/ml (P<0.05).