This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.

Teodoro, CL, Gáspari, AF, Berton, R, Barbieri, JF, Silva, M, Castaño, LAA, Guimarães, P, and Moraes, AC. Familiarization with airflow-restriction mask during resistance exercise: Effect on tolerance and total volume. J Strength Cond Res 33(7): 1762–1765, 2019—This study investigated whether familiarization with the airflow-restriction mask (AIRfr) increases tolerance and avoids negative effects on performance of resistance exercise (RE). Ten resistance-trained male subjects performed a familiarization session (FAM), followed by 2 testing sessions, with the AIRfr and without airflow restriction (SHAM) in a counterbalanced and randomized cross-over design. The FAM was performed with the same number of sets, load, and level of airflow-restriction as the AIRfr experimental session. Each session consisted of 4 sets of the leg press exercise with 70% 1 repetition maximum until voluntary failure and a 90-second rest interval between sets. During the FAM, 4 of the 10 subjects expressed some intolerance to the use of airflow restriction. Total volume was lower in the FAM than in the AIRfr (p = 0.01) and the SHAM (p = 0.02), whereas no differences were observed between the AIRfr and the SHAM (p = 0.90). The first use of the AIRfr may not be well tolerated by all subjects. However, a familiarization session with the AIRfr avoids negative interferences in the total volume during RE.

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Introduction:The Wingate Test (WAnT) has been used to evaluate anaerobic performance in cycle ergometer. Objective: The purpose of the present study was to analyze the EMG response of the superficial quadriceps femoris muscles during the Wingate anaerobic test (WAnT). In addition, we investigated the influence of these muscles in performance and fatigue during the WAnT. Methods: For this purpose eight male cyclists performed a 30-s WAnT. Electromyographic amplitude (RMS) and median power frequency (MPF) data of the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles, performance index (mean power, MP) and rate of fatigue (fatigue index, FI) were recorded during the test; and compared along six time points. The correlation between EMG data and performance parameters were made. Results: No significant differences were found in maximal EMG amplitude for all the muscles. The MPF of the VL and VM muscles decreased throughout the test (12% and 13%, respectively), however, the decline for the RF was twice greater (25%). Correlation among MP and EMG amplitude was observed only for VL (r=0.83; P<0.01). There was significant correlation between the FI and the MPF decrease in the RF muscle only (r=0.78; P<0.05). Conclusion: During the WAnT, MPF decrease of RF muscle was significantly larger when compared to the VL and VM. The VL muscle electrical activity was positively correlated with MP, suggesting that VL is an accurate predictor of the performance in the WAnT. The MPF decrease of the RF muscle was positively correlated to the FI. These results may be explained by differences in the fiber type composition, biomechanics and architecture properties of these muscles.

A emissão de infravermelho (IV) sobre a musculatura é uma estratégia eficiente para a melhora do desempenho físico. No entanto, os equipamentos convencionais para emissão de IV são dependentes de fonte elétrica e de pouca mobilidade dificultando seu uso em práticas esportivas reais. Tecidos contendo nanopartículas capazes de emitir IV podem ser a solução para a aplicação de IV no esporte. No entanto, seus possíveis efeitos foram pouquíssimo investigados. Esse estudo, utilizando um desenho randomizado, cruzado, duplo-cego e controlado por placebo, testa os efeitos do tecido emissor de IV longo sobre o desempenho de ciclistas. Demostramos que o uso do tecido resultou em redução no tempo de prova contrarrelógio de 4000m, sem alterar a temperatura do quadríceps. Contudo, nenhum dos mecanismos testados foram alterados, sugerindo outros fatores como responsáveis pelos benefícios do tecido IV.