The relationship between V̇O2 and muscle deoxygenation kinetics and upper body repeated sprint performance in trained judokas

• Autor(a) principal: Antunes, André Gonçalo de Sá
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.5/24613
• topic: V̇ O2 kinetics; Judo; Upper body; Arm crank; Near-infrared spectroscopy; Repeated sprint; Cinética de V̇O2; Judo; Ergómetro de braços; Membros superiores; Espectroscopia de infravermelhos próximo; Sprints repetidos; Domínio/Área Científica::Ciências Sociais::Outras Ciências Sociais

Judo is a sport characterized by short periods of maximal-intensity activity, interceded with short periods of rest, akin to repeated sprint efforts. Moreover, it relies heavily on upper body musculature. The maintenance of performance over the course of several repeated sprint efforts seems to be related to the ability to recover quickly in between efforts, which has been linked to muscular oxidative capacity. The measurement of oxygen uptake kinetics (V̇O2 Kinetics) and muscle haemoglobin/myoglobin deoxygenation kinetics ([HHb] kinetics) constitute non-invasive parameters that provide a surrogate of muscular oxidative capacity. The purpose of this study was to determine if an association could be established between V̇O2 Kinetics, [ HHb] kinetics, and other parameters of aerobic fitness and upper body repeated sprint (RSA) performance, and if these associations were observed in a separate group of trained judo athletes (JT) and in a group of untrained individuals (UT). Fifteen participants, consisting of eight judo athletes (age 21,1 ± 3,0 yr, height 172,3 ± 4,5 cm, body mass 71,5 ± 7,1 kg) and seven healthy individuals untrained in upper body exercise modalities (age 22,6 ± 1,0 yr, height 172,71 ± 4,5 cm, age 64,29 ± 5,8 kg) were recruited as participants for the study. Each participant completed an arm crank incremental test to determine peak oxygen consumption (peak V̇O2), maximal aerobic power (MAP) and the first ventilatory threshold (VT1). On a subsequent day, two heavy-intensity square-wave exercise transitions of 6 minutes at 20% Δ (20% the workload ranging from VT1 to MAP) were performed to determine V̇O2 and [HHb] kinetics. On a following session, participants performed an upper body RSA test (4 sprints x 15:45-s work: rest), where [HHb] parameters were monitored, along with peak (PPO) and mean (MPO) power output, total work performed (W) over the course of each sprint. During all testing sessions, pulmonary gas exchange variables were measured breath-by-breath and [HHb] data of the triceps brachii was monitored by near-infrared spectroscopy (NIRS). All correlations were established for the JT and UT groups, separately, and for a group of heterogenous fitness level consisting of the whole sample. No significant correlations were found between V̇O2 and [HHb] kinetics and upper body RSA performance both in the JT group and the UT group. However, a strong negative correlation was found between the MAP and the decrease in PPO (↓PPO) between the first and last sprint (r = -0,74, p = 0,002) and a strong positive correlation was found between the MAP and the accumulated work (ΣWork) throughout the four sprints (r = 0,83, p < 0,001) when we consider the whole sample as a heterogenous group and in the UT group. A strong negative correlation was found between the peak V̇O2 and the ↓ PPO between the first and last sprint ( r = - 0,81, p < 0,001) and a strong positive correlation was found between the peak V̇O2 and the ΣWork throughout all sprints (r = 0,70, p = 0,004) when we consider the whole sample as a heterogenous group and in the UT group. Significant strong negative correlations were observed between the peak V̇O2 and the ↓PPO (r = -0,83; p = 0,022), the decrease in mean power output (↓MPO) (r = -0,80; p = 0,030) and the decrease in work (↓Work) performed between the first and fourth sprints (r = -0,80; p = 0,030) when we consider the whole sample as a heterogenous group and in the UT group. A linear regression found Maximal [HHb] amplitude (Max. A[HHb]) in the fourth sprint and peak V̇O2 to be significant predictors of ΣWork throughout all sprints. When each group is analysed separately, no significant predictors of ΣWork throughout the upper body RSA test were found. We can conclude that V̇O2 and [HHb] kinetics are not associated with an increased upper body RSA. However, other variables of aerobic fitness seem to be associated with increased upper body RSA performance in a group of individuals with heterogeneous fitness level. This suggests that aerobic fitness variables may play an important role in upper body RSA performance. However, once a certain level of upper body aerobic fitness is attained, other physiological and fitness variables may play a more important role in determining upper body RSA performance.