Cardiac autonomic nervous activity during different sleep stages in individuals with spinal cord injury: The influence of physical training.

OBJECTIVE: The present study assessed the influence of physical training on cardiac autonomic activity in individuals with spinal cord injury (SCI) during different sleep stages. METHODS: Twenty-six volunteers were allocated into three groups: 9 sedentary individuals without SCI (control, CON); 8 sedentary tetraplegic individuals with chronic SCI (SED-SCI); 9 physically trained tetraplegic individuals with chronic SCI (TR-SCI). All participants underwent nocturnal polysomnography to monitor sleep stages: wakefulness, non-rapid eye movement (NREM) sleep (N1, N2, and N3 stages), and REM sleep. The electrocardiography data obtained during this exam were extracted to analyze the heart rate variability (HRV). RESULTS: Sleep stages influenced HRV in the time [RR interval and root mean square of successive RR interval differences (RMSSD)] and frequency [low-frequency (LF) and high-frequency (HF) powers and LF-to-HF ratio] domains (P < 0.05). SED-SCI individuals showed unchanged HRV compared to CON (P > 0.05). When comparing the TR-SCI and SED-SCI groups, no significant differences in HRV were reported in the time domain (P > 0.05). However, in the frequency domain, more accentuated HF power was observed in TR-SCI than in SED-SCI individuals during the N2 and N3 stages and REM sleep (P < 0.05). Moreover, TR-SCI had higher HF power than CON during the N3 stage (P < 0.05). CONCLUSIONS: TR-SCI individuals have greater HF power, indicative of parasympathetic modulation, than sedentary (injured or not injured) individuals during different sleep stages. Therefore, enhanced parasympathetic activity induced by physical training may improve cardiac autonomic modulation during sleep in individuals with chronic SCI.

Total Testosterone and Cortisol During Wheelchair Rugby Training in Athletes With Cervical Spinal Cord Injury.

CONTEXT: Hormonal assessment in the sport context is important to monitor the physiological adaptations of athletes. However, Paralympic athletes, especially with cervical spinal cord injury (CSCI), may have different hormonal responses than nondisabled athletes. Therefore, the aim of this study was to evaluate the blood concentrations of total testosterone (TT) and cortisol (C) during acute (one training session) and chronic (1 and 2 month) training of athletes with CSCI in wheelchair rugby (WCR). DESIGN: Longitudinal and observational study. METHODS: Eight high-performance athletes with CSCI (31 [3.9] y; 75.6 [15.8] kg; 22.9 [4.2] kg/m2 body mass index; 6.2 [2] y of experience in sport) were evaluated at 3 different intervals (evaluations 1, 2, and 3 [E1, E2, and E3]) over 2 months of training. TT and C blood were evaluated before (pre) and after (post) the training sessions at each training moment, as well as the training load through the ratings of perceived exertion. RESULTS: Athletes with CSCI had low TT concentrations. In acute training sessions, at E3, C decreases after the training session, unlike the TT/C ratio, which increased after the session. Regarding hormonal changes during chronic training at the end of the training period, unlike C, which increased. The training load (arbitrary units) decreased in E3 when compared with the other evaluation moments. CONCLUSION: It was concluded that in chronic training, TT concentrations decreased, while C increased at the end of the 2 months of training. These results may indicate that training volume was high throughout training and that a reduction in training volume could benefit athletes. On the other hand, in the acute training session with reduced training load, a decrease in C was observed after the training session. This indicates that athletes may be well recovered in this training session. Therefore, we suggest acute and long-term hormonal assessment for athletes with CSCI as a strategy to monitor anabolic/catabolic hormonal status during WCR training.

Training load, stress, recovery, mood, and motivation of athletes with spinal cord injury in wheelchair rugby during a competitive preseason

Abstract Aim: This study aims to characterize the stress, recovery, mood, and motivation together with the training load of athletes with cervical spinal cord injury (CSCI) during a period of resumption of wheelchair rugby (WCR) training. Additionally, it aims to compare the psychological and load training aspects during a competitive preseason and determine the correlations between training load, mood, stress, and recovery. Methods: We evaluated variables such as mood (Brazilian Mood Scale, BRAMS), stress and recovery (Recovery-Stress Questionnaire for Athletes, RESTQ-Sport 76) and training load (Subjective Perception of Effort - SPE) of eight high-performance athletes of wheelchair rugby with CSCIs at three different times (E1 = returning from vacation, E2 = half of the preseason, and E3 = after 2 months of training) for 2 months at a monthly interval. We also evaluated motivation (Sport Motivation Scale) at E1 and E3. Results: Results indicated few changes during the competitive preseason in terms of stress, recovery, and mood. However, the training load decreased toward the end of this period. Furthermore, we found that physical complaints positively correlated with depression when resuming training. In the middle of the competitive preseason period, we also noted positive correlations between conflict/pressure and fatigue and between fatigue and energy loss. At the end of this period, the SPE and arbitrary units correlated positively with conflict/pressure. Conclusion: We found few changes during the competitive preseason in terms of stress, recovery, and mood but not motivation, which did not change during this period. On the other hand, the training load decreased at the end of the competitive preseason. Furthermore, we observed correlations between training load and psychological aspects at different times.