Influence of an Acute Exposure to a Moderate Real Altitude on Motoneuron Pool Excitability and Jumping Performance
Metadata
Show full item recordEditorial
Frontiers
Materia
Drop jump H-reflex Hypoxia Squat jump Altitude
Date
2022-04-25Referencia bibliográfica
Štirn I... [et al.] (2022) Influence of an Acute Exposure to a Moderate Real Altitude on Motoneuron Pool Excitability and Jumping Performance. Front. Physiol. 13:861927. doi: [10.3389/fphys.2022.861927]
Sponsorship
Slovenian Research Agency - Slovenia P5-0142Abstract
The aim of the study was to test whether ascending to a moderate real altitude affects
motoneuron pool excitability at rest, as expressed by a change in the H-reflex amplitude,
and also to elucidate whether a possible alteration in the motoneuron pool excitability could
be reflected in the execution of lower-body concentric explosive (squat jump; SJ) and fast
eccentric-concentric (drop jump; DJ) muscle actions. Fifteen participants performed four
experimental sessions that consisted of the combination of two real altitude conditions [low
altitude (low altitude, 690 m), high altitude (higher altitude, 2,320 m)] and two testing
procedures (H-reflex and vertical jumps). Participants were tested on each testing day at 8,
11, 14 and 17 h. The only significant difference (p < 0.05) detected for the H-reflex was the
higher H-reflex response (25.6%) obtained 15 min after arrival at altitude compared to
baseline measurement. In terms of motor behavior, DJ height was the only variable that
showed a significant interaction between altitude conditions (LA and HA) and time of
measurement (8, 11, 14 and 17 h) as DJ height increased more during successive
measurements at HA compared to LA. The only significant difference between the LA
and HA conditions was observed for DJ height at 17 h which was higher for the HA
condition (p = 0.04, ES = 0.41). Although an increased H-reflex response was detected
after a brief (15–20 min) exposure to real altitude, the effect on motorneuron pool
excitability could not be confirmed since no significant changes in the H-reflex were
detected when comparing LA and HA. On the other hand, the positive effect of altitude on
DJ performance was accentuated after 6 h of exposure.