Thigh Ischemia-Reperfusion Model Does Not Accelerate Pulmonary VO2 Kinetics at High Intensity Cycling Exercise

• Published in: Frontiers in physiology Vol. 10
• Main Authors: Helal, Lucas, do Nascimento Salvador, Paulo Cesar, de Lucas, Ricardo Dantas, Guglielmo, Luiz Guilherme Antonacci
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 25-02-2019
• Subjects: cardiopulmonary test; exercise physiology; ischemia-reperfusion; oxygen uptake kinetics; physical exercise; Physiology
• ISSN: 1664-042X; 1664-042X
• DOI: 10.3389/fphys.2019.00160

Background:
We aimed to investigate the effect of a priming ischemia-reperfusion (IR) model on the kinetics of pulmonary oxygen uptake (VO
2
) and cardiopulmonary parameters after high-intensity exercise. Our primary outcome was the overall VO
2
kinetics and secondary outcomes were heart rate (HR) and O
2
pulse kinetics. We hypothesized that the IR model would accelerate VO
2
and cardiopulmonary kinetics during the exercise.
Methods:
10 recreationally active men (25.7 ± 4.7 years; 79.3 ± 10.8 kg; 177 ± 5 cm; 44.5 ± 6.2 mL kg
−1
min
−1
) performed a maximal incremental ramp test and four constant load sessions at the midpoint between ventilatory threshold and VO
2
max on separate days: two without IR (CON) and two with IR (IR). The IR model consisted of a thigh bi-lateral occlusion for 15 min at a pressure of 250 mmHg, followed by 3 min off, before high-intensity exercise bouts.
Results:
There were no significant differences for any VO
2
kinetics parameters (VO
2
base 1.08 ± 0.08 vs. 1.12 ± 0.06 L min
−1
;
P
= 0.30; τ = 50.1 ± 7.0 vs. 47.9 ± 6.4 s;
P
= 0.47), as well as for HR (MRT
180s
67.3 ± 6.0 vs. 71.3 ± 6.1 s;
P
= 0.54) and O
2
pulse kinetics (MRT
180s
40.9 ± 3.9 vs. 48.2 ± 5.6 s;
P
= 0.31) between IR and CON conditions, respectively.
Conclusion:
We concluded that the priming IR model used in this study had no influence on VO
2
, HR, and O
2
pulse kinetics during high-intensity cycling exercise.