The Effects of Virtual Reality Nonphysical Mental Training on Balance Skills and Functional Near-Infrared Spectroscopy Activity in Healthy Adults.

CONTEXT: Athletic skills such as balance are considered physical skills. However, these skills may not just improve by physical training, but also by mental training. The purpose of this study was to investigate the effects of mental training programs on balance skills and hemodynamic responses of the prefrontal cortex. DESIGN: Randomized controlled trial. METHODS: Fifty-seven healthy adults (28 females, 29 males), aged between 18-25 years, participated in this study. Participants were randomly assigned to 3 groups: virtual reality mental training (VRMT) group, conventional mental training (CMT) group, and control group. The training program included action observation and motor imagery practices with balance exercise videos. The VRMT group trained with a VR head-mounted display, while the CMT group trained with a non-immersive computer screen, for 30 minutes, 3 days per week for 4 weeks. At baseline and after 4 weeks of training, balance was investigated with stabilometry and Star Excursion Balance Test (SEBT). Balance tests were performed with simultaneous functional near-infrared spectroscopy (fNIRS) imaging to measure prefrontal cortex oxygenation. RESULTS: For the stabilometry test, at least 1 variable improved significantly in both VRMT and CMT groups but not in the control group. For SEBT, composite reach distance significantly increased in both VRMT and CMT groups but significantly decreased in the control group. For separate directional scores, reach distance was significantly increased in both mental training groups for nondominant leg posterolateral and posteromedial directions, and dominant leg posterolateral direction, while nondominant posteromedial score was significantly increased only in the VRMT group. Between-group comparisons showed that dominant leg posteromedial and posterolateral score improvements were significantly higher than control group for both mental training groups, while nondominant leg improvements were significantly higher than control group only for the VRMT group. The fNIRS oxyhemoglobin levels were not significantly changed during stabilometry tests. However, oxyhemoglobin levels significantly reduced only in the control group during SEBT. CONCLUSIONS: Our findings suggest that both mental training interventions can significantly improve balance test results. Additionally, VRMT may have some advantages over CMT. These findings are promising for the use of mental training in prevention and rehabilitation for special populations such as athletes and older adults.

The relationships between simulated tennis performance and biomarkers for nitric oxide synthesis.

Tennis performance requires a good aerobic endurance and recovering capacity. Nitric oxide (NO) is a gas which is not only a vasodilator and antioxidant but it also regulates the use of oxygen and glucose. The aim of this study was to examine the relationships between simulated tennis performance test (PT) and NOx (sum of nitrate+nitrite) levels and lactate elimination speed (LES). Twenty well trained male tennis players with game levels of ITN 4 (International Tennis Number) and lower (mean ± SD; age 22.9 ± 2.6 yrs; height 1.82 ± 0.06 m and mass 75.7 ± 8.0 kg) participated in the study. Participants performed three 4-min bouts and a 2-min continuous groundstroke against balls projected from a tennis ball machine at speeds of 50, 55, 62 and 70 km·h(-1). After this exercise, subjects were given a 20 min passive rest. After each period and at during the recovery phase; plasma NOx, glucose (GLU) and lactate (LA) levels were determined. LES was calculated during passive recovery. GLU, LA and heart rate (HR) showed a linear increase in comparison to the values in the previous step while PT decreased significantly. Following each period NOx and glucose levels increased independently, but their decreasing rates in recovery phase were related (r = 0.470, p < 0.05). The successive increase in NOx and GLU parameters between the third and the forth periods was significant (p < 0.05). Only in the third period was there a significant relation between PT and NOx (r = 0.494; p < 0.05). In the present study, no significant relationship was found between PT and GLU, LA levels and LES. No significant correlation was found between simulated tennis performance and blood NOx levels. However the addition of loads like those in the third period in tennis trainings can be beneficial for performance in trained tennis players. It is recommended that the relationships between tennis performance with NOx and GLU are studied during a real tennis match. Key PointsIn a sport like tennis which lasts 2-6 hours and has short rests, performance depends on the player's capacity to perform the intensive exercise intermittently. Therefore, recovering potential is important in tennis.In none of the periods of this study were the expected (significant) relations observed of the athletes. Therefore, it can be claimed that LA increase, LA elimination and aerobic endurance do not play a significant role in the performance and the decrease in performance in this exercise model.

Exercise Improves Physical Capacity, Cognition, Quality of Life and Promotes Neurotrophic Factors in Patients with Multiple Sclerosis.

Introduction: We aimed to determine the effect of regular exercise on aerobic capacity, strength values, and plasma levels of Nerve Growth Factor (NGF) and Neurotrophin-3 (NT-3) in patients with multiple sclerosis (MS) and investigate its effects on MS symptoms including cognitive impairment, fatigue, balance disorders, and quality of life (QOL). Methods: Forty-three relapsing-remitting MS patients with an Expanded Disability Status Scale (EDSS) score of 4 or less participated in the study. Participants were divided into three groups: aerobic group, strength group, and control group. The patients in the exercise groups had exercise programs three days a week for three months. Aerobic capacity (maximum VO2 value), strength measurements, and balance tests were done, and NGF and NT-3 plasma levels were analyzed in all participants at the beginning and end of the study. Multiple Sclerosis Quality of Life-54 (MSQoL-54), fatigue impact scale, Pittsburgh Sleep Quality Index (PSQI) and, to evaluate cognitive functions, BICAMS scale were applied. Results: Aerobic exercise and strength exercise groups had significant increases in VO2 max, back and leg strength values, and NGF and NT-3 plasma levels (p<0.01). Cognitive functions, fatigue, sleep quality, and QOL significantly improved in the exercise groups (p<0.01). The balance values were also significantly improved in the aerobic group (p<0.01), and althoughimprovement although improvement was observed in the strength group, it was not statistically significant (p>0.05). Conclusions: Our study provides evidence that regular exercise improves quality of life, cognitive functions, fatigue, and sleep quality in MS patients. The levels of NGF and NT-3, which are important factors in neural regeneration and remyelination, were increased post exercise. It can be suggested that exercise may have a potential effect on MS and slow down the disease process with these results.

The effects of fatigue on linear and angular kinematics during bilateral squat.

This study was aimed to analyze in detail how the fatigue effects to kinematic parameters of body weight squat exercise (BSQ) by dividing a squat cycle into four different regions. Twenty-one male athletes participated in this study. Participants were divided into two groups according to their lower limb muscle ratio (LLMR). The BSQ was performed until participants were unable to continue the exercise due to the fatigue. Linear and angular kinematics were obtained by motion analysis software which has high validity and reliability. There was no significant but had large effect size interaction between fatigue conditions and LLMR groups in terms of knee ROM in the extension phase and hip angular velocity in braking phase of the flexion (0.08 > p >0.05, 0.18 > [Formula: see text] > 0.16). Fatigue condition did not have a significant effect on the duration in the acceleration and braking phases of BSQ (p > 0.05). There were many significant main effects on kinematics in the different regions due to the fatigue (0.01 < p <0.05, 0.44 > [Formula: see text] > 0.14). In the fatigue condition, there was a polynomial relationship between velocity of shoulder and hip joints (R2flex = 0.82, R2ext = 0.72) rather than linear (R2flex = 0.64, R2ext = 0.53) and coefficient correlations also decreased (rflex = 0.88 to 0.80, rext = 0.92 to 0.73). The sticking region was observed in the non-fatigue condition and disappeared when fatigue occurred. These results suggest that LLMR may be taken into consideration in the squat exercises, joint tracking may vary for velocity-based squat training and pre-test for sticking region observation may be apply with the BSQ.

Can different variations of suspension exercises provide adequate loads and muscle activations for upper body training?

The purpose of this study was to assess the differences in muscle activation (EMG) and body weight distribution (%BW) between suspension (TRX™ push-up and TRX™ inverted row) and conventional exercises (bench press and lying barbell row) using different contraction types (isometric and isotonic) and position variations (feet on the ground [FG] and feet on suspension device [FD]). It was also used to determine the intensity of the force applied to the straps of the suspension device corresponding to one repetition maximum (1-RM). Twelve male athletes (ages-24.5±4.2 years (mean±standard deviation [SD]); Height-181.0±6.8 cm; body mass-83.08±6.81 kg) participated in this study. Two suspension devices were used, one for the FD variation and one for the FG variation pectoralis major (PM) and triceps brachii (TRI) activations were assessed during the TRX™ push-up and bench press exercises. Transversus trapezius (TRA) and biceps brachii (BB) activations were assessed during the TRX™ inverted row and lying barbell row exercises. The results showed significant differences between exercises (FG and FD variations of TRX™ push-up and bench press) in PM activities (isometric and isotonic) (p≤0.05). However, these differences were only observed during isometric TRI activation (p≤0.05). In the FG and FD variations of the TRX™ inverted row and lying barbell row exercises, there were only differences in the isometric contractions of the TRA and BB (p≤0.05). In the suspension device of push-ups and inverted row for the FD variations, 70.5% and 72.64% of 1-RM intensity were obtained, respectively. Similar responses to training intensities and muscle activations can be obtained in suspension exercises and conventional exercises. FD variations of suspension exercises can be more effective in terms of muscle activations than FG variations, and isotonic suspension exercises increase exercise intensity more than isometric suspension exercises.

The effects of vibration on efficiency in off-road cyclists.

OBJECTIVES: The aim of this study was to investigate whether vibration significantly affected the efficiency of off-road cyclists. PATIENTS AND METHODS: Eight male mountain cyclists (mean age 21.1±1 years; range, 19 to 22 years) between August 2017 and November 2017 were included. The experimental protocol included four testing sessions with a one-day interval between testing sessions: a familiarization session; performance of submaximal tests; performance of maximal graded exercise test; and a 30-min mountain bike trial performed with vibration or without vibration. Physiological measures including volume of oxygen uptake (VO2), volume of 2), VO2, VCO2, heart rate, respiratory exchange ratio, rating of perceived exertion, and gross efficiency (GE) were compared between the trials performed with vibration or without vibration. RESULTS: There was a significant increase in the GE with the addition of intermittent vibration, particularly over the last 15 min of the cycling trial (p<0.05). There were no significant effects of vibration on other parameters. CONCLUSION: This study demonstrates that addition of intermittent vibration may provide positive benefits in improving GE during a 30-min submaximal cycling trial.

Assessments of Ground Reaction Force and Range of Motion in Terms of Fatigue during the Body Weight Squat.

The purpose of this study was to analyse in detail body weight squat (BWS)' fatigue effect on the range of motions (ROM) of the hip, knee, ankle and ground reaction forces (GRF). Twenty male recreational athletes (24.0 ± 3.1 years, 178.85 ± 7.12 cm and 78.7 ± 11.45 kg) participated in this study. BWS were performed on four load cell platforms until the participants failed to continue. Participants performed 73 ± 27 repetitions and the duration to complete of the repetitions was 140.72 ± 62.28 s during the BWS exercise. The forefoot and hindfoot of the feet were on two load cells, thus, there were two under each foot. All of the data collected was divided into three sections for analysis (24 ± 9 repetitions for each). In terms of GRF of the fore feet and hind feet, significant differences and medium to large effect size were found between each section (p = 0.006~0.040, ES = 0.693~0.492). No significant differences were found between right and left leg in all sections. Significant differences were found in the ROM of the hip between the sections of first-third (p = 0.044, ES = 0.482) and second-third (p = 0.034, ES = 0.510), the ROM of the knee first-third (p = 0.014, ES = 0.602) and second-third (p = 0.005, ES = 0.701) and for the ROM of the ankle first-second (p = 0.045, ES = 0.479). As a result, end-of-exercise fatigue caused an increase in the ROM of the hip, knee and ankle. Thus, it is observed that fatigue induced increased ROM, also increases the GRF towards the forefeet.