Cardiac Rehabilitation Improves Endothelial Function in Coronary Artery Disease Patients.

Exercise-based cardiac rehabilitation may be an effective non-pharmacological intervention for improving endothelial function in coronary artery disease patients. Therefore, this systematic review with meta-analysis aimed to (a) estimate the training-induced effect on endothelial and vascular smooth muscle function, assessed by flow-mediated dilation and nitroglycerin-mediated dilation, respectively, in coronary artery disease patients; and to (b) study the influence of potential trial-level variables (i. e. study and intervention characteristics) on the training-induced effect on endothelial and vascular smooth muscle function. Electronic searches were performed in Pubmed, Scopus, and Embase up to February 2021. Random-effects models of standardised mean change were estimated. Heterogeneity analyses were performed by using the Chi 2 test and I 2 index. Our results showed that exercise-based cardiac rehabilitation significantly enhanced flow-mediated dilation (1.04 [95% confidence interval=0.76 to 1.31]) but did not significantly change nitroglycerin-mediated dilation (0.05 [95% confidence interval=-0.03 to 0.13]). Heterogeneity testing reached statistical significance (p<.001) with high inconsistency for flow-mediated dilation (I 2 =92%). Nevertheless, none of the analysed variables influenced the training-induced effect on flow-mediated dilation. Exercise-based cardiac rehabilitation seems to be an effective therapeutic strategy for improving endothelial-dependent dilation in coronary artery disease patients, which may aid in the prevention of cardiovascular events.

Analysis of scored goals in the cerebral palsy football World Cup.

This study aimed to report the goal patterns in cerebral palsy (CP) football for a better understanding of the performance of this para-sport. All goals (270) of the 48 2019 IFCPF World Cup matches were analysed through match reports, and 65% of them were analysed by video footage. The results showed 5.6 goals per match. Teams that scored more and conceded fewer goals correlated to a better ranking position in the championship (r= 0.72-0.73; p< 0.01). The distribution of goals scored was not biased by halves (49.3% vs 50.7%; χ2= 0.1; p= 0.88) nor by 15-min periods (26.3% vs 23.0% vs 23.3% vs 27.4%; χ2= 0.5; p= 0.92). In 91.7% of the matches, the team which scored the first goal went on to win the match (χ2= 81.5; p< 0.01). FT3 players scored more goals by player (χ2= 22.1; p< 0.01), while there were no statistical differences in the distribution of goals conceded by goalkeepers according to their sport class (χ2= 4.7; p= 0.09). The goals were scored mainly from organized attacks (74.4%), from the penalty area (52.5%) and through individual action (51.9%). All this information could be crucial for coaches in CP football to plan their game strategies.

Predicting BMX Performance with Laboratory Measurements in Elite Riders.

In Bicycle Motocross (BMX) performance is determined by the riders' sprint ability and power output. Therefore, descriptive and predictive performance assessments through laboratory and field tests are of interest. Twelve members of the Spanish BMX National Team performed 4 laboratory tests, including 1RM in squat, a Wingate test, a 5x6-s repeated sprint test (RST) and a force-velocity profile test. These tests were compared with the riders' field performance using the best lap of a simulated BMX competition consisting of 6 all-out laps on a standard BMX track. Pearson's correlation and linear regression analysis showed a significant association (p < 0.05) between the riders' field performance and the 1RM (r = 0.84; R2 = 0.65), the peak power output in the RST (r = 0.87; R2 = 0.78) and the peak power, the mean power and the lactate production in the Wingate test (r = 0.68-0.77; R2 = 0.14-0.65), as well as maximal power from the force-velocity profile (r = 0.71; R2 = 0.53). The laboratory tests included in this study can show information about BMX riders' performance, with the highest values for the peak power obtained in the repeated sprint test (78% of the variance in common).

Exercise-based cardiac rehabilitation and parasympathetic function in patients with coronary artery disease: a systematic review and meta-analysis.

PURPOSE: The effects of exercise-based cardiac rehabilitation (CR) on parasympathetic modulation are controversial. This systematic review and meta-analysis aims to (a) determine the effect of exercise-based CR on heart-rate-derived indices associated with cardiac parasympathetic modulation in resting and post-exercise conditions in coronary artery disease (CAD) patients and (b) identify the possible moderator variables of the effect of exercise-based CR on parasympathetic modulation. METHODS: We searched CENTRAL and Web of Science up to November 2018 for the following terms: adult CAD patients, controlled exercise-based CR interventions and parasympathetic modulation measured in resting (vagal-related heart rate variability [HRV] indices of the root mean square of the differences in successive in RR interval [RMSSD] and high frequency [HF]) and post-exercise (heart rate recovery [HRR]) pre- and post-intervention. We estimated a random-effects model of standardised mean difference (SMD) and mean difference (MD) for vagal-related HRV indices and HRR, respectively. We assessed the influence of categorical and continuous variables. RESULTS: The overall effect size showed significant differences in RMSSD (SMD+ = 0.30; 95% confidence interval [CI] = 0.12-0.49) and HRR (MD+ = 5.35; 95% CI = 4.08-6.61 bpm) in favour of the exercise-based CR group. The overall effect size showed no differences in HF between groups (SMD+ = 0.14; 95% CI, -0.12-0.40). Heterogeneity analyses reached statistical significance, with high heterogeneity for HF (p < 0.001; I2 = 70%) and HRR (p < 0.001; I2 = 85%). Analysis of the moderator variables showed that the effect on HRR is greater in young patients (p = 0.008) and patients treated with percutaneous intervention (p = 0.020). CONCLUSIONS: Exercise-based CR improves the post-exercise parasympathetic function, with greater effects in younger CAD patients and in those who were revascularised with percutaneous intervention. The effects on resting parasympathetic function are more controversial due to methodological inconsistencies in measuring HRV, with the use of RMSSD recommended instead of HF because its results show higher consistency. Future studies involving women, focusing on methodological issues, and performing other training methods are needed to increase our knowledge about this topic.

Heart rate-based indices to detect parasympathetic hyperactivity in functionally overreached athletes. A meta-analysis.

Investigations into the sensitivity of heart rate-(HR) derived indices for tracking parasympathetic nervous system (PNS) changes in functionally overreached (F-OR) endurance-trained athletes have produced equivocal findings. Lack of clarity may be a result of methodological inconsistencies. Therefore, the aims of this systematic review and meta-analysis were (a) to determine the sensitivity of resting and post-exercise vagal-related HR variability (HRV) and HR recovery (HRR) indices to detect PNS modulation in F-OR and non-overreached (non-OR) athletes, and (b) to investigate the influence of methodological factors on the sensitivity of HR-based indices to detect PNS hyperactivity in F-OR athletes. We searched CENTRAL, Scopus, PubMed, Embase, and Web of Science up to May 2020 for the following terms: male and female endurance-trained athletes, controlled and uncontrolled studies that carried out an overload training period, and PNS modulation measured in resting and post-exercise, pre- and post-overload training period. A random-effects model of standardized mean difference (SMD) was estimated for each outcome measure based on the training-induced fatigue status (F-OR vs non-OR athletes), and the influence of methodological issues to detect PNS hyperactivity in F-OR was assessed by subgroup analyses. Pooled analysis showed that resting vagal-related HRV indices did not detect PNS hyperactivity in F-OR athletes (SMD+ = -0.01; 95% confidence interval [CI] = -0.51, 0.50), and no statistical difference (P = .600) was found with non-OR athletes (SMD+ = 0.15; 95% CI = -0.14, 0.45). However, subgroup analysis based on HRV parameter showed a moderate statistical increase in weekly averaged HRV in F-OR athletes (SMD+ = 0.81; 95% CI = 0.35, 1.26), while isolated HRV values did not reach statistical significance (SMD+ = -0.45; 95% CI = -0.96, 0.06). We observed a moderate and statistically significant increase in HRR indices among F-OR athletes (SMD+ = 0.65; 95% CI = 0.44, 0.87), no changes for non-OR athletes (SMD+ = 0.10; 95% CI = -0.15, 0.34), and statistically significant differences between F-OR and non-OR athletes (P < .001). Insufficient data prevented meta-analysis for post-exercise vagal-related HRV indices. Our findings show that when methodological factors are considered, HR-based indices are sensitive to increased PNS modulation in F-OR.

The Use of a Smartphone Application in Monitoring HRV during an Altitude Training Camp in Professional Female Cyclists: A Preliminary Study.

Altitude training is a common strategy to improve performance in endurance athletes. In this context, the monitoring of training and the athletes' response is essential to ensure positive adaptations. Heart rate variability (HRV) has been proposed as a tool to evaluate stress and the response to training. In this regard, many smartphone applications have emerged allowing a wide access to recording HRV easily. The purpose of this study was to describe the changes of HRV using a validated smartphone application before (Pre-TC), during (TC), and after (Post-TC) an altitude training camp in female professional cyclists. Training load (TL) and vagal markers of heart rate variability (LnRMSSD, LnRMSSDcv) of seven professional female cyclists before, during, and after and altitude training camp were monitored. Training volume (SMD = 0.80), LnRMSSD (SMD = 1.06), and LnRMSSDcv (SMD = -0.98) showed moderate changes from Pre-TC to TC. Training volume (SMD = 0.74), TL (SMD = 0.75), LnRMSSD (SMD = -1.11) and LnRMSSDcv (SMD = 0.83) showed moderate changes from TC to Post-TC. Individual analysis showed that heart rate variability responded differently among subjects. The use of a smartphone application to measure HRV is a useful tool to evaluate the individual response to training in female cyclists.

Are the Current Cardiac Rehabilitation Programs Optimized to Improve Cardiorespiratory Fitness in Patients? A Meta-Analysis.

Previous meta-analyses have shown that high-intensity interval training (HIIT) is more suitable than moderate continuous training (MCT) for improving peak oxygen uptake (VO2peak) in patients with coronary artery disease. However, none of these meta-analyses have tried to explain the heterogeneity of the empirical studies in optimizing cardiac rehabilitation programs. Therefore, our aims were (a) to estimate the effect of MCT and HIIT on VO2peak, and (b) to find the potential moderator variables. A search was conducted in PubMed, Scopus, and ScienceDirect. Out of the 3,110 references retrieved, 29 studies fulfilled the selection criteria to be included in our meta-analysis. The mean difference was used as the effect size index. Our results showed significant enhancements in VO2peak after cardiac rehabilitation based on MCT and HIIT (mean difference = 3.23; 95% confidence interval [2.81, 3.65] ml·kg-1·min-1 and mean difference = 4.61; 95% confidence interval [4.02, 5.19] ml·kg-1·min-1, respectively), with greater increases after HIIT (p < .001). Heterogeneity analyses reached statistical significance with moderate heterogeneity for MCT (p < .001; I2 = 67.0%), whereas no heterogeneity was found for the effect of HIIT (p = .220; I2 = 22.0%). Subgroup analyses showed significant between-group heterogeneity of the MCT-induced effect based on the training mode (p < .001; I2 = 90.4%), the risk of a new event (p = .010; I2 = 77.4%), the type of cardiovascular event (p = .009; I2 = 84.8%), the wait time to start cardiac rehabilitation (p = .010; I2 = 76.6%), and participant allocation (p = .002; I2 = 89.9%). Meta-regressions revealed that the percentages of patients undergoing a revascularization procedure (B = -0.022; p = .041) and cardiorespiratory fitness at baseline (B = -0.103; p = .025) were inversely related to the MCT-induced effect on the VO2peak.

Training Prescription Guided by Heart Rate Variability Vs. Block Periodization in Well-Trained Cyclists.

Javaloyes, A, Sarabia, JM, Lamberts, RP, Plews, D, and Moya-Ramon, M. Training prescription guided by heart rate variability vs. block periodization in well-trained cyclists. J Strength Cond Res 34(6): 1511-1518, 2020-Predefined training programs are common place when prescribing training. Within predefined training, block periodization (BP) has emerged as a popular methodology because of its benefits. Heart rate variability (HRV) has been proposed as an effective tool for prescribing training. The aim of this study is to examine the effect of HRV-guided training against BP in road cycling. Twenty well-trained cyclists participated in this study. After a preliminary baseline period to establish their resting HRV, cyclists were divided into 2 groups: an HRV-guided group and a BP group, and they completed 8 training weeks. Cyclists completed 3 evaluations weeks, before and after each period. During the evaluation weeks, cyclists performed: (a) a graded exercise test to assess V[Combining Dot Above]O2max, peak power output (PPO), and ventilatory thresholds with their corresponding power output (VT1, VT2, WVT1, and WVT2, respectively) and (b) a 40-minute simulated time-trial (40 TT). The HRV-guided group improved V[Combining Dot Above]O2max (p = 0.03), PPO (p = 0.01), WVT2 (p = 0.02), WVT1 (p = 0.01), and 40 TT (p = 0.04). The BP group improved WVT2 (p = 0.02). Between-group fitness and performance were similar after the study. The HRV-guided training could lead to a better timing in training prescription than BP in road cycling.

Influence of Training Models at 3,900-m Altitude on the Physiological Response and Performance of a Professional Wheelchair Athlete: A Case Study.

Sanz-Quinto, S, López-Grueso, R, Brizuela, G, Flatt, AA, and Moya-Ramón, M. Influence of training models at 3,900-m altitude on the physiological response and performance of a professional wheelchair athlete: A case study. J Strength Cond Res 33(6): 1715-1723, 2019-This case study compared the effects of two training camps using flexible planning (FP) vs. inflexible planning (IP) at 3,860-m altitude on physiological and performance responses of an elite marathon wheelchair athlete with Charcot-Marie-Tooth disease (CMT). During IP, the athlete completed preplanned training sessions. During FP, training was adjusted based on vagally mediated heart rate variability (HRV) with specific sessions being performed when a reference HRV value was attained. The camp phases were baseline in normoxia (BN), baseline in hypoxia (BH), specific training weeks 1-4 (W1, W2, W3, W4), and Post-camp (Post). Outcome measures included the root mean square of successive R-R interval differences (rMSSD), resting heart rate (HRrest), oxygen saturation (SO2), diastolic blood pressure and systolic blood pressure, power output and a 3,000-m test. A greater impairment of normalized rMSSD (BN) was shown in IP during BH (57.30 ± 2.38% vs. 72.94 ± 11.59%, p = 0.004), W2 (63.99 ± 10.32% vs. 81.65 ± 8.87%, p = 0.005), and W4 (46.11 ± 8.61% vs. 59.35 ± 6.81%, p = 0.008). At Post, only in FP was rMSSD restored (104.47 ± 35.80%). Relative changes were shown in power output (+3 W in IP vs. +6 W in FP) and 3,000-m test (-7s in IP vs. -16s in FP). This case study demonstrated that FP resulted in less suppression and faster restoration of rMSSD and more positive changes in performance than IP in an elite wheelchair marathoner with CMT.

Monitoring Heart Rate Variability Before and After a Marathon in an Elite Wheelchair Athlete: A Case Study.

The purpose of this study was to analyze heart rate variability (HRV) oscillations before and after a marathon which involved trans-meridian air travel and substantial time zone differences in a professional wheelchair athlete with Charcot-Marie-Tooth (CMT) disease. The natural logarithm of the root mean square difference between adjacent normal R-R intervals (Ln rMSSD) was measured daily on the days before, including and following the race. Relative to baseline, small (-3.8 - -4.6%) reductions in LnRMSSD were observed following relocation and on race-day, indicating only minor effects of travel on cardiac-autonomic activity. On the morning following the marathon, a 23.1% reduction in Ln rMSSD was observed, which returned to baseline by 48 h. The race time set by the athlete was the world-leading time in his class. This case study showed that Ln rMSSD responses to marathon in an elite wheelchair athlete with CMT was similar to those previously reported among unrestricted endurance athletes.

Rest Interval Required for Power Training With Power Load in the Bench Press Throw Exercise.

This study aimed to test the influence of various rest interval (RI) durations used between sets on power output performance and physiological and perceptual variables during a strength training session using 40% of the 1 repetition maximum (1RM) in the bench press throw exercise. Thirty-one college students (18 males and 13 females) took part in the study. The experimental protocol consists of 5 sets of 8 repetitions of the bench press throw exercise with a load representing 40% of 1RM. Subjects performed the experimental protocol on 3 different occasions, differing by the RI between sets (1, 2, or 3 minutes). During the sessions, power data (mean power and peak power), physiological (lactate concentration [La]) and perceptual (rating of perceived exertion) variables were measured. In addition, delayed onset muscular soreness was reported 24 and 48 hours after the training session. One-way repeated-measures analysis of variance showed that 1-minute RI entailed higher power decreases and greater increases in values of physiological and perceptual variables compared with both 2- and 3-minute RIs. Nevertheless, no differences were found between 2- and 3-minute RIs. Therefore, this study showed that, when training with 40% of 1RM in the bench press throw exercise, a 2-minute RI between sets can be enough to avoid significant decreases in power output. Consequently, training sessions' duration could be reduced without causing excessive fatigue, allowing additional time to focus on other conditioning priorities.

Individualized exercise prescription in non-alcoholic steatohepatitis: a case report.

The effect of an individualized exercise programme on a non-alcoholic steatohepatitis case is presented. Before entering the programme the patient was treated with conventional recommendations on diet plus aerobic exercise during fourteen years, without major improvements of his analytical parameters.Two years after including him in a tailored exercise programme, aimed to fulfil the recommendations of the American College of Sports Medicine, his blood markers of liver dysfunction and cardiometabolic risk tended to improve. Consequently, our data support the idea that in non-alcoholic steatohepatitis the exercise-based therapeutic interventions should be individualized taking into account the cardio-respiratory and muscular fitness of the patient, rather than using generic behavioural recommendations.

Assessing sleep quality in elite and junior cyclists.

In the pursuit of optimal recovery, the significance of sleep cannot be overstated for elite cyclists, including high-level cyclists within the junior category. This study aims to assess the sleep quality of elite athletes of different categories and disciplines, including junior. The sleep quality of 112 high-level cyclists (males n = 80; females n = 32) participating in endurance and sprint disciplines was evaluated using the Pittsburgh Sleep Quality Index (PSQI). A noteworthy 41% of both elite and junior cyclists displayed poor sleep quality. No significant differences were observed between elite and junior cyclists in terms of sleep quality, but there was a medium effect size, indicating greater sleep efficiency in junior cyclists [0.36 (0.16, 0.53)]. Gender differences were found, with females exhibiting worse PSQI scores (males = 4.00 [2.25]; females 5.00 [3.00]; p = 0.035). Endurance cyclists spent more time in bed compared to cyclists from sprinting disciplines (8:30 [1.00] and 8:00 [1:03], respectively; p = 0.019). These findings reveal poor sleep habits, even among individuals classified as good sleepers by the PSQI, emphasizing the importance of preventing sleep disorders in cyclists. This study provides valuable insights into athlete sleep quality, encompassing various categories, genders, and cycling disciplines. In conclusion, elite cyclists demonstrate suboptimal sleep quality, suggesting the potential for interventions utilizing the PSQI. These findings advocate for the incorporation of sleep quality assessments into routine evaluations for athletes.

Reliability and validity of a non-linear index of heart rate variability to determine intensity thresholds.

Exercise intensity distribution is crucial for exercise individualization, prescription, and monitoring. As traditional methods to determine intensity thresholds present limitations, heart rate variability (HRV) using DFA a1 has been proposed as a biomarker for exercise intensity distribution. This index has been associated with ventilatory and lactate thresholds in previous literature. This study aims to assess DFA a1's reliability and validity in determining intensity thresholds during an incremental cycling test in untrained healthy adults. Sixteen volunteers (13 males and 3 females) performed two identical incremental cycling stage tests at least 1 week apart. First and second ventilatory thresholds, lactate thresholds, and HRV thresholds (DFA a1 values of 0.75 and 0.5 for HRVT1 and HRVT2, respectively) were determined in heart rate (HR), relative oxygen uptake (VO2rel), and power output (PO) values for both tests. We used intraclass correlation coefficient (ICC), change in mean, and typical error for the reliability analysis, and paired t-tests, correlation coefficients, ICC, and Bland-Altman analysis to assess the agreement between methods. Regarding reliability, HRV thresholds showed the best ICCs when measured in PO (HRVT1: ICC = .87; HRVT2: ICC = .97), comparable to ventilatory and lactate methods. HRVT1 showed the strongest agreement with LA 2.5 in PO (p = 0.09, r = .93, ICC = .93, bias = 9.9 ± 21.1), while HRVT2 reported it with VT2 in PO (p = 0.367, r = .92, ICC = .92, bias = 5.3 ± 21.9). DFA a1 method using 0.75 and 0.5 values is reliable and valid to determine HRV thresholds in this population, especially in PO values.

Acute Antioxidant Response to Two Types of Exercises: 2000 M Run vs. Burpee Test.

Physical activity results in oxidative stress, as evidenced by the increased production of reactive oxygen, nitrogen species, and inflammatory mediators. The management of these components is instrumental for antioxidant adaptation to exercise and post-exercise recovery. Therefore, the present report aims to study the antioxidant response to two types of exercise (a 2000 m run and a burpee test) in healthy volunteers after a long period of inactivity (1-2 months). Antioxidant enzyme activities and oxidative stress markers (protein carbonyls and malondialdehyde content) were measured in neutrophils, peripheral blood mononuclear cells, and plasma. These parameters were determined under basal conditions and immediately post-exercise. Compared to those in basal state, neutrophil superoxide dismutase (28.3 vs. 22.9 pkat/109 cells), glutathione peroxidase (147.5 vs. 120.1 nkat/109 cells), and catalase (106.3 vs. 57.9 k/109 cells) were activated significantly (p < 0.05) after the burpee test. Peripheral blood mononuclear cells exhibited only significant (p < 0.05) catalase activation (113.6 vs. 89.4 k/109 cells) after the burpee test. Other enzymes, such as glutathione reductase and myeloperoxidase, tended to increase post-exercise, although the differences from baseline were not significant. Finally, compared to basal conditions, the protein carbonyl (24.5 vs. 14.5 mmol/L) and malondialdehyde (39.6 vs. 18.3 mmol/L) contents increased significantly (p < 0.05) in neutrophils and in plasma (115.1 vs. 97.8 and 130.2 vs. 123.4 µmol/L, respectively) after the burpee test. In conclusion, high-intensity exercise seems to induce immediate oxidative stress in inactive individuals, and the acute antioxidant response was slightly greater after the burpee test than after the 2000 m run. Glutathione-dependent antioxidant systems are activated immediately as protective mechanisms.

Exploring the Impact of Web-Based vs. In-Person Exercise Training on Benefits and Adherence in Substance Use Disorder Interventions: A Pilot Study.

BACKGROUND: Substance use disorders pose unique challenges, affecting individuals physiologically and socially. This study addresses the fundamental question of how adherence to exercise programs impacts those with substance use disorders, examining both in-person and online interventions. METHODS: A 12-week analysis involving 26 participants assessed physical fitness, strength, and quality of life. Participants were categorized into in-person and online exercise groups, with their adherence tracked through attendance and a dedicated app. RESULTS: The in-person group exhibited higher adherence rates and significant improvements, in contrast to the challenges encountered by the online groups, particularly in substance use disorder cohorts. Statistical analyses highlighted these differences, emphasizing the pivotal role of the exercise program delivery format. CONCLUSIONS: This research advocates for hybrid models, blending professional supervision with online flexibility, recognizing the distinct challenges of substance use disorders. Insights from this study will contribute to shaping more effective, personalized interventions in the complex landscape of substance use disorders, offering guidance for advancing treatment strategies.

Gender differences in game responses during badminton match play.

The aim of this study was to evaluate possible gender differences in match play activity pattern [rally duration, rest time between rallies, effective playing time, and strokes performed during a rally] and exercise intensity (heart rate [HR], blood lactate [La], and subjective ratings of perceived exertion [RPE]) during 9 simulated badminton matches in male (n = 8) and female (n = 8) elite junior (16.0 ± 1.4 years) players. Results showed significant differences (all p < 0.05; effect size (ES) = 0.80-1.56) between male and female players in the activity pattern of match play, with male players engaged in longer rallies (6.8 ± 4.8 vs. 5.7 ± 3.1 seconds), executing more strokes per rally (6.4 ± 4.8 vs. 4.7 ± 2.8) and resting more between rallies (10.5 ± 8.8 vs. 8.8 ± 7.2 seconds) than female players. No clear differences (all p > 0.05; ES = -0.33 to 0.08) were observed between female or male players in average HR (174 ± 7 vs. 170 ± 9 b·min(-1)), %HRmax (89.2 ± 4.0% vs. 85.9 ± 4.3%), La (2.5 ± 1.3 vs. 3.2 ± 1.8 mmol·L(-1)), and RPE values (14.2 ± 1.9 vs. 14.6 ± 1.8) during match play, although male players spent more time (moderate effect sizes) at intensities between 81 and 90% HRmax (35.3 ± 17.9 vs. 25.3 ± 13.6; p < 0.05; ES = 0.64) in the second game. There seemed to be a trend toward an increased playing intensity (i.e., higher HR, La, and RPE) from the first to the second game, highlighting the higher exercise intensity experienced during the last part of the match. The clear between-gender differences in activity patterns induced only slightly different physiological responses.

Changes in Sprint Force-Velocity Profile in International Para Footballers.

PURPOSE: Force production is crucial in football, and it is the main limitation of people with cerebral palsy (CP). This study aimed to describe the changes in sprint force-velocity (Fv) profile after a period of 25 weeks of regular training in international football players with CP. METHODS: The sprint Fv profile and other physical performance variables (ie, linear sprint, vertical jump, change of direction, and intermittent endurance) of 14 international players from the Spanish national team were assessed during 2 consecutive training camps. Pretesting and posttesting sessions were carried out 1 week before and after the 25-week intervention period. The intervention consisted of 2 strength sessions per week added to the usual football training. RESULTS: The repeated-measures analysis of variance showed changes in players' physical performance (linear sprint: F = 18.05, P < .01; change of direction: F = 16.71, P < .01; and endurance: F = 31.45, P < .01) and in some variables of the sprint Fv profile (maximal horizontal force, maximal power, slope, maximal ratio of force, and decrease of ratio of force; F = 14.28-37.81; P < .01), whereas players' maximal velocity (theoretical and actual) did not change (F = 0.13 and 0.01; P = .72 and .98, respectively). CONCLUSIONS: This study showed that the implementation of 2 strength-training sessions per week, for 25 weeks, is effective to improve CP football players' physical performance. The main finding of this study is the improvement of force application in the acceleration phase (sprint Fv profile), which is the main attribute in many physical performance tests and is the main limitation of the CP population.

Validity of detrended fluctuation analysis of heart rate variability to determine intensity thresholds in elite cyclists.

Background: The evaluation of performance in endurance athletes and the subsequent individualisation of training is based on the determination of individual physiological thresholds during incremental tests. Gas exchange or blood lactate analysis are usually implemented for this purpose, but these methodologies are expensive and invasive. The short-term scaling exponent alpha 1 of detrended Fluctuation Analysis (DFA-α1) of the Heart Rate Variability (HRV) has been proposed as a non-invasive methodology to detect intensity thresholds. Purpose: The aim of this study is to analyse the validity of DFA-α1 HRV analysis to determine the individual training thresholds in elite cyclists and to compare them against the lactate thresholds. Methodology: 38 male elite cyclists performed a graded exercise test to determine their individual thresholds. HRV and blood lactate were monitored during the test. The first (LT1 and DFA-α1-0.75, for lactate and HRV, respectively) and second (LT2 and DFA-α1-0.5, for lactate and HRV, respectively) training intensity thresholds were calculated. Then, these points were matched to their respective power output (PO) and heart rate (HR). Results: There were no significant differences (p > 0.05) between the DFA-α1-0.75 and LT1 with significant positive correlations in PO (r = 0.85) and HR (r = 0.66). The DFA-α1-0.5 was different against LT2 in PO (p = 0.04) and HR (p = 0.02), but it showed significant positive correlation in PO (r = 0.93) and HR (r = 0.71). Conclusions: The DFA1-a-0.75 can be used to estimate LT1 non-invasively in elite cyclists. Further research should explore the validity of DFA-α1-0.5.HighlightsThe power and heart rate values derived from the DFA-α1-0.75 threshold showed high levels of validity and agreement when they were compared against the first lactate threshold.The second lactate threshold and the DFA-α1-0.5 were different (p < 0.05) but showed high levels of correlation.The detrended fluctuation analysis is a valid method to estimate the first lactate threshold and more studies are needed to verify its validity with the second lactate threshold.

Effects of physical activity/exercise on tear film characteristics and dry eye associated symptoms: A literature review.

PURPOSE: To conduct a review of the literature in order to identify the potential association between physical activity or exercise and the objective signs and/or subjective symptoms of dry-eye disease. METHODS: A review of PubMed and Web of Science databases was performed, according to the PRISMA guidelines. The papers included in the review addressed the relationship of physical activity or exercise with dry-eye associated signs (changes in tear volume, osmolarity or biochemical composition) and/or subjective symptoms. RESULTS: A total of 16 papers were included. In eight, the changes in tear film volume, osmolarity and/or biochemical composition were studied after a single, acute bout of aerobic exercise. In another eight, changes in dry-eye associated symptoms were studied in relation to the habitual practice of physical activity or to prescribed exercise programmes. Acute responses of the tear film to exercise included: a) an increase of tear volume, without an increase of the tear break-up time; b) a trend to increase tear osmolarity, although within its physiological range; and c) a reduced concentration of several cytokines, and other molecular markers of inflammation or oxidative stress. Long-term exposure to physical activity or exercise programmes was associated with relief of dry-eye associated symptoms and a trend to increased tear break-up time. CONCLUSIONS: Despite a high heterogeneity in the studied population, study designs and methods, the current body of evidence suggests a potential role for physical activity as a modulatory stimulus for the proper functioning of the tear film and/or the relief of dry-eye symptoms.