Increased Training Volume Research Articles

\u201cMore air\u2014better performance\u2014faster recovery\u201d: study protocol for randomised controlled trial of the effect of post-stroke inspiratory muscle training for adults

BackgroundStroke results in varying physical, cognitive, emotional and/or social disabilities in the short and long term alike. Motor impairments are important, persistent consequences of stroke and include, among others, decreased respiratory muscle function, decreased ability to expand the thorax and postural dysfunction. These deficits affect the patient’s ability to perform daily activities, produce fatigue and reduce endurance and quality of life. Inspiratory muscle training (IMT) aims to improve the strength and endurance of the diaphragm and the external intercostal muscles. The objectives of this study are to investigate the effect of 3 weeks of IMT on (i) maximal inspiratory pressure (MIP) in adults having suffered a stroke, as well as (ii) functional activities and expiratory measurements.Methods/designThis is a randomised controlled trial (RCT) comparing IMT with conventional neurorehabilitation (usual practice). The trial will include 80 patients with reduced MIP hospitalised at a specialised neurorehabilitation hospital in Denmark. The intervention group will receive IMT sessions, exercising at 30% of MIP. Patients in the intervention group will perform two daily sessions (one session of IMT with Threshold IMT consisting of two times 15 inspirations at normal breathing rhythm (5–10 min)), 7 days a week for 3 weeks. Training can be with or without physiotherapist supervision. Study outcomes: MIP assessed by the Power Breath, Functional Independence Measurement, The 6-min walk test, the Fatigue Severity Scale and average voice volume. Expiratory function will be assessed using spirometry. All assessments will be conducted at baseline and 3 weeks (at termination of the intervention) and 3 months after the intervention has concluded.DiscussionIMT is a promising and partly self-managed tool for rehabilitation to improve respiratory function. The introduction of IMT in combination with traditional physical therapy may enhance faster recovery after stroke and may at the same time demand little personnel resources to increase training intensity. This trial will provide further evidence of IMT to clinicians, patients and health managers. Hereby, this study accepts the call for further research.Trial registrationClinicalTrials.govNCT04686019. Registered on 28 December 2020.

Exercise Training Induces Left- but not Right-sided Cardiac Remodelling in Olympic Rowers.

Whilst the athlete's heart has been extensively described, less work has focused on the potential for elite athletes to demonstrate further cardiac remodelling upon an increase in training volume. Moreover, little work explored potential side-specific cardiac remodelling. Therefore, we examined the impact of an increase in training volume across 9-months in elite rowers on left- and right-sided cardiac structure, function and mechanics (i. e. longitudinal, radial and circumferential strain, twist and strain-volume loops). As part of the preparations to the 2012 Olympic Games, twenty-seven elite rowers (26.4±3.7years, 19 male) underwent echocardiography prior to and post (9 months) an increase in training volume (24 to 30-35 h weekly). Training increased left ventricular structure, including wall thickness, diameter, volume, mass and LV twist (all p<0.05). Female rowers demonstrated larger adaptation in left ventricular diameter and mass compared to male rowers (both p<0.05). No changes were observed in other measures of left ventricular function in both sexes (all p>0.05). The 9-month intervention showed no change in right ventricular/atrial structure, function or mechanics (all p>0.05). In conclusion, our data revealed that 9-month increased training volume in elite rowers induced left-sided (but not right-sided) structural remodelling, concomitant with an increase in left ventricular twist, with some changes larger in women.

The influence of exercise training volume alterations on the gut microbiome in highly-trained middle-distance runners

ABSTRACT The aim of this study was to determine the influence of training volume alterations on diversity and composition of the gut microbiome in a free-living cohort of middle-distance runners. Fourteen highly-trained middle-distance runners (n = 8 men; O2peak = 70.1 ± 4.3 ml·kg·min−1; n = 6 women, O2peak: 59.0 ± 3.2 ml·kg·min−1) completed three weeks of normal training (NormTr), three weeks of high-volume training (HVolTr; a 10, 20 and 30% increase in training volume during each successive week from NormTr), and a one-week taper (TaperTr; 55% exponential reduction in training volume from HVolTr week three). Faecal samples were collected before and immediately after each training phase to quantify alpha-diversity and composition of the gut microbiome. A three-day diet record was collected during each training phase and a maximal incremental running test was completed after each training phase. Results showed no significant changes in nutritional intake, alpha-diversity, or global microbial composition following HVolTr or TaperTr compared to NormTr (p’s > 0.05). Following HVolTr, there was a significant decrease in Pasterellaceae (p = 0.03), Lachnoclostridium (p = 0.02), Haemophilus (p = 0.03), S. parasagunis (p = 0.02), and H. parainfluenzae (p = 0.03), while R. callidus (p = 0.03) significantly increased. These changes did not return to NormTr levels following TaperTr. This study shows that the alpha-diversity and global composition of the gut microbiome were unaffected by changes in training volume. However, an increase in training volume led to several changes at the lower taxonomy levels that did not return to pre-HVolTr levels following a taper period.

The efficacy of cardiac rehabilitation on exercise performance in men and women

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Slovenian Research Agency Background Over the last years exercise training has gained IA class recommendation as a core component of cardiac rehabilitation (CR) in patients with coronary artery disease (CAD). Despite the strong evidence of higher mortality and rehospitalisation rates in women compared with men with CAD, women are less frequently enrolled in CR programs and show lower exercise adherence. However, when enrolled women showed similar improvement as men, but this remains to be further elucidated. Purpose The aim of this study was to examine the gender differences in improvement of exercise performance in patients with CAD following CR programme. Methods A total of 91 patients with CAD (74 men and 17 women, mean (SD), aged 59 (11) years and 60 (10) years, p &amp;gt; 0.05; median (interquartile range), height 177 (173, 181) cm and 159 (158, 167) cm, p &amp;lt; 0.001; weight 92.1 (82.4, 98.6) kg and 72.3 (69.1, 79.6) kg, p = 0.001, respectively) participated in out-patient CR. Each patient completed 36 exercise sessions comprised of general warm up with calisthenics, followed by 5 aerobic intervals of cycling on stationary bikes (5 minutes of loaded cycling at the intensity of 50 %-70% of peak power separated by 2 minutes intervals of unloading cycling) and finished with stretching and breathing exercises. Training load and target training heart rate were increased every two weeks. The exercise test was performed at baseline and after CR. Results At baseline, there was a significant difference between men and women in peak power (P max) (men 122 (25) W vs. women 74 (19) W, p &amp;lt; 0.001), maximum oxygen consumption (VO2 max; men 19.45 (3.60) ml/kg/min vs. women 16.00 (3.35) ml/kg/min, p &amp;lt; 0.001) and exercise test time (men 658 (150) s vs. women 363 (115) s, p &amp;lt; 0.001). During the training both genders increased training intensity (men: +34 (12) W and women: +25 (9) W, both p &amp;lt; 0.001) and target heart rate (men: +10 (5, 19) bpm and women: +10 (5, 20) bpm, both p &amp;lt; 0.001), whereas training intensity was increased more in men than women (+9 W, p = 0.003). Exercise training led to improvement in P max (men: +15 (20) W, p &amp;lt; 0.001, women: +14 (12) W, p &amp;lt; 0.001), VO2 max (men: +1.87 (2.52) ml/kg/min, p &amp;lt; 0.001, women: +2.47 (2.05) ml/kg/min, p &amp;lt; 0.001) and exercise test time (men: +99 (134) s, p &amp;lt; 0.001, women +95 (90) s, p &amp;lt; 0.001). In addition, after adjusting for baseline values there were no sex differences in post training P max, VO2 max and exercise test time. Conclusions CR improved the exercise performance similarly in men and women, thus, more women should be encouraged to enrol into CR programmes. Still, larger and adequately powered randomised studies are warranted to further elucidate this issue.

Associations Between Health Status, Training Level, Motivations for Exercise, and Supplement Use Among Recreational Runners

Dietary supplement use continues to increase, with athlete use surpassing non-athlete utilization. Most research has been conducted on dietary supplement use in elite or collegiate-level athletes. This study investigated supplement use in adult recreational runners and determined relationships between supplement use and participants’ training volume, motivations for exercise, self-reported health status, and reasons for using dietary supplements. Participants (n = 283) were recruited for this cross-sectional study via a convenience sampling method. Participants completed an electronic questionnaire using Likert-scale response options. Correlations between the aggregate variables of health status, training level, exercise motivation, reasons for using supplements, and supplement use were calculated using bivariate Pearson correlation analysis. There was a positive correlation between the variables exercise motivation and supplement use (r = 0.267, n = 276, p = 0.01), and between variables influencing reasons for using dietary supplements and reported supplement use was also found (r = 0.425, n = 276, p = 0.01). There was no correlation between health status and supplement use (r = 0.043, n = 275, p = 0.476), or between training level and supplement use (r = 0.00, n = 275, p = 0.994). This study demonstrated a positive correlation between runners’ supplement use and motivations for exercising and reasons for consuming supplements. A significant relationship was not found between supplement use and participants’ health status or supplement use and runners’ training volume. This finding contrasts with previous research in supplement use in the athlete population, which largely reports increased dietary supplement use with increased training volume.

Can non-responders be ‘rescued’ by increasing exercise intensity? A quasi-experimental trial of individual responses among humans living with pre-diabetes or type 2 diabetes mellitus in Canada

IntroductionExercise is recommended to improve glycaemic control. Yet, individual changes in glycaemic control following exercise can vary greatly, meaning while some significantly improve others, coined ‘non-responders’, do not. Increasing the...

Utility of Back-Off Sets: An Overview

ABSTRACT Back-off sets or down sets are a training paradigm that use an initial heavy loaded set followed by a subsequent rest period and a planned load reduction. Back-off sets are a way to maintain or increase training volume through a load reduction for subsequent sets. By reducing load, a desired number of repetitions can be achieved as opposed to a reduction in volume that would occur if a consistent load was maintained. Back-off sets have been shown to allow completion of a greater training volume which may be in part due to a potentiation effect. The use of back-off sets help to reduce the necessary length of interset rest periods. Back-off set utility may be influenced by factors including but not limited to training goals, training age, exercise type, protocol individualization, loading strategy, load-reduction strategy, and autoregulation. This discussion aims to provide an overview of the integration of back-off sets within resistance training programs by examining previous research and providing a synopsis of the variables that impact the efficacy of this strategy.

Monitoring Training and Recovery during a Period of Increased Intensity or Volume in Recreational Endurance Athletes.

The purpose of the study was to examine the effects of progressively increased training intensity or volume on the nocturnal heart rate (HR) and heart rate variability (HRV), countermovement jump, perceived recovery, and heart rate-running speed index (HR-RS index). Another aim was to analyze how observed patterns during the training period in these monitoring variables were associated with the changes in endurance performance. Thirty recreationally trained participants performed a 10-week control period of regular training and a 10-week training period of either increased training intensity (INT, n = 13) or volume (VOL, n = 17). Changes in endurance performance were assessed by an incremental treadmill test. Both groups improved their maximal speed on the treadmill (INT 3.4 ± 3.2%, p < 0.001; VOL 2.1 ± 1.8%, p = 0.006). In the monitoring variables, only between-group difference (p = 0.013) was found in nocturnal HR, which decreased in INT (p = 0.016). In addition, perceived recovery decreased in VOL (p = 0.021) and tended to decrease in INT (p = 0.056). When all participants were divided into low-responders and responders in maximal running performance, the increase in the HR-RS index at the end of the training period was greater in responders (p = 0.005). In conclusion, current training periods of increased intensity or volume improved endurance performance to a similar extent. Countermovement jump and HRV remained unaffected, despite a slight decrease in perceived recovery. Long-term monitoring of the HR-RS index may help to predict positive adaptations, while interpretation of other recovery-related markers may need a more individualized approach.

Pre-flight exercise and bone metabolism predict unloading-induced bone loss due to spaceflight

ObjectivesBone loss remains a primary health concern for astronauts, despite in-flight exercise. We examined changes in bone microarchitecture, density and strength before and after long-duration spaceflight in relation to biochemical...

Running behaviors, motivations, and injury risk during the COVID-19 pandemic: A survey of 1147 runners.

The COVID-19 pandemic has influenced activity behaviors worldwide. Given the accessibility of running as exercise, gaining information on running behaviors, motivations, and running-related injury (RRI) risk during the pandemic is warranted. The purpose of this study was to assess the influence of the COVID-19 pandemic on running volume, behaviors, motives, and RRI changes from the year prior to the pandemic to the timeframe during social isolation restrictions. Runners of all abilities were recruited via social media to complete a custom Qualtrics survey. Demographics, running volume, behaviors, motivations, and injury status were assessed for the year prior to the pandemic, and during social isolation measures. Descriptive statistics and Student's t-tests were used to assess changes in running outcomes during the pandemic. Logistic regressions were used to assess the influence of demographics on running behaviors and injury. Adjusted RRI risk ratios were calculated to determine the odds of sustaining an injury during the pandemic. Alpha was set to.05 for all analyses. A total of 1147 runners (66% females, median age: 35 years) across 15 countries (96% United States) completed the survey. Runners reported increased runs per week (Mean Difference with Standard Error [MD]: 0.30 [0.05], p < .001), sustained runs (MD: 0.44 [0.05], p < .001), mileage (MD: 0.87 [0.33], p = .01), and running times of day (MD: 0.11 [0.03], p < .001) during the pandemic, yet reported less workouts (i.e. sprint intervals; MD: -0.33 [0.06], p < .001), and less motives (MD [SE]: -0.41 [0.04], p < .001). Behavior changes were influenced by running experience and age. There was 1.40 (CI: 1.18,1.61) times the RRI risk during the pandemic compared to prior to the social isolation period. The COVID-19 pandemic influenced runners' behaviors with increased training volume, decreased intensity and motivation, and heightened injury risk. These results provide insights into how physical activity patterns were influenced by large-scale social isolation directives associated with the pandemic.

Enriched Music-supported Therapy for chronic stroke patients: a study protocol of a randomised controlled trial

BackgroundResidual motor deficits of the upper limb in patients with chronic stroke are common and have a negative impact on autonomy, participation and quality of life. Music-Supported Therapy (MST) is an effective intervention to enhance motor and cognitive function, emotional well-being and quality of life in chronic stroke patients. We have adapted the original MST training protocol to a home-based intervention, which incorporates increased training intensity and variability, group sessions, and optimisation of learning to promote autonomy and motivation.MethodsA randomised controlled trial will be conducted to test the effectiveness of this enriched MST (eMST) protocol in improving motor functions, cognition, emotional well-being and quality of life of chronic stroke patients when compared to a program of home-based exercises utilizing the Graded Repetitive Arm Supplementary Program (GRASP). Sixty stroke patients will be recruited and randomly allocated to an eMST group (n = 30) or a control GRASP intervention group (n = 30). Patients will be evaluated before and after a 10-week intervention, as well as at 3-month follow-up. The primary outcome of the study is the functionality of the paretic upper limb measured with the Action Research Arm Test. Secondary outcomes include other motor and cognitive functions, emotional well-being and quality of life measures as well as self-regulation and self-efficacy outcomes.DiscussionWe hypothesize that patients treated with eMST will show larger improvements in their motor and cognitive functions, emotional well-being and quality of life than patients treated with a home-based GRASP intervention.Trial registrationThe trial has been registered at ClinicalTrials.gov and identified as NCT04507542 on 8 August 2020.

Knee wraps increase torque production during passive isometric knee extension

Knee wraps (KW) can be used as an ergogenic aid during the back squat to increase training volume and load. Previous investigations have examined carryover effect during the back squat, though the amount of torque produced at the knee due to the KWs remains unknown. Therefore, this investigation examined the influence of KWs on passive torque production, and its relationship to knee circumference. Nine resistance trained men performed two, 5 second passive isometric knee extensions with (KW) and without (UW) knee wraps at nine different angles (70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, and 110°). Data were analyzed via two-way repeated measures ANOVA to assess differences between conditions, while Pearson's product-moment correlations were used to assess the relationship between torque production and knee circumference. A significant interaction was observed for passive torque, revealing differences between all angles in KW (P ≤ .05), while differences during UW were only observed at angles greater than 90° (P ≤ .05). Paired samples t-tests indicated differences between conditions at every angle except 70° (P ≤ .05). Knee circumference was not correlated to torque production at any angle (r = ≤ .411, P > .272). These results demonstrate the applicability of KW to passively increase torque produced at the knee during extension, independent of knee circumference.

Analysis of Training Loads among Swimmers with Disabilities during Specific Preparation Period

The research goal was to analyse training loads during specific preparation period among swimmers with disabilities. Double examination of 20 athletes with disabilities of motion and sight organs, at the beginning and at the end of the period was conducted. Garmin Forerunner 735XT device was used as a measuring tool, which registered heartbeat rate during training sessions. Records of the heartbeat rate were sent up to Garmin Connect programme, where percentage share of each energy zone in the whole training volume was calculated. Taking into consideration the achieved results, during specific preparation period, swimmers were training mostly with moderate and high intensity and the biggest training volume was registered in zones EN2, EN3 and SP1. Additionally, between the first and the second measurement, the biggest decrease in training volume took place in EN, whereas the biggest increase in training volume took place in zone SP1 what indicates increase of work in the field of specific endurance.

Effects of Four Different Velocity-Based Training Programming Models on Strength Gains and Physical Performance

Riscart-López, J, Rendeiro-Pinho, G, Mil-Homens, P, Costa, RS-d, Loturco, I, Pareja-Blanco, F, and León-Prados, JA. Effects of Four different velocity-based training programming models on strength gains and physical performance. J Strength Cond Res 35(3): 596-603, 2021-The aim of this study was to compare the effects of 4 velocity-based training (VBT) programming models (linear programming [LP], undulating programming [UP], reverse programming [RP], and constant programming [CP]) on the physical performance of moderately strength-trained men. Forty-three young (age: 22.9 ± 4.8 years; body mass [BM]: 71.7 ± 7.6; full squat [SQ] relative strength 1.32 ± 0.29) subjects were randomly assigned to LP (gradually increase training intensity and decrease volume), UP (volume and intensity increase or decrease repeatedly), RP (gradually increases volume and decrease intensity), and CP (maintains constant volume and intensity) groups and followed an 8-week VBT intervention using the SQ exercise and monitoring movement velocity for every repetition. All groups trained with similar relative average intensity (67.5% 1 repetition maximum [1RM]), magnitude of velocity loss within the set (20%), number of sets (3), and interset recoveries (4 minutes) throughout the training program. Pre-training and post-training measurements included predicted SQ (1RM), average velocity attained for all loads common to pre-tests and post-tests (AV), average velocity for those loads that were moved faster (AV > 1) and slower (AV < 1) than 1 m·s-1 at pre-tests, countermovement jump height (CMJ), and 20-m sprint time (T20). No significant group × time interactions were observed for any of the variables analyzed. All groups obtained similar increases (shown in effect size values) in 1RM strength (LP: 0.88; UP: 0.54; RP: 0.62; CP: 0.51), velocity-load-related variables (LP: 0.74-4.15; UP: 0.46-5.04; RP: 0.36-3.71; CP: 0.74-3.23), CMJ height (LP: 0.35; UP: 0.53; RP: 0.49; CP: 0.34), and sprint performance (LP: 0.34; UP: 0.35; RP: 0.32; CP: 0.30). These results suggest that different VBT programming models induced similar physical performance gains in moderately strength-trained subjects.

Endurance Exercise Training Modes to Improve Physical Function in Older Mice: HIIT vs. VWR

With age, we experience a progressive loss of physical function. Exercise is a promising therapy to preserve muscle health and functional aptitude. Animal models are needed to examine the underlying molecular mechanisms at the intersection of aging, exercise, and functional decline. In this study, we compare the efficacy of two types of individualized endurance exercise training in older C57BL/6 mice (26-months old at completion): HIIT (high intensity interval training on a treadmill, n=10) and VWR (voluntary wheel running, n=8). We hypothesized that while both exercises would improve function, HIIT would promote more extensive adaptation. For four months the VWR mice ran 4 days/week and the HIIT group ran 3x/week. We determined function pre/post-training by utilizing our composite scoring system, the Comprehensive Functional Assessment Battery (CFAB). CFAB consists of the following: treadmill running (endurance), rotarod (overall motor function), wheel running (volitional exercise rate/activity), grip strength (fore-limb strength), and inverted cling (overall strength/endurance). EchoMRI determined body composition. After training, we found significant CFAB improvement (repeated measures t-test, p<0.05) in both exercise groups, specifically including: rotarod (+37%, HIIT and VWR); treadmill (+61% VWR; +58% HIIT), grip strength (+20% VWR), body mass (-17% VWR, -10% HIIT), and fat percentage (-44% VWR, -20% HIIT). Contrary to our hypothesis, HIIT did not improve function more than VWR, though we suspect increasing training intensity would improve response. Thus, future studies will need to address defining HIIT dose response and optimal training volume for older mice. We conclude that our models will be useful for future mechanistic investigations.

The Effect of 8 Weeks of Complex Training Methods on the Countermovement Jump Performance

PURPOSE The purpose of this study was to find out whether a more specific stimulus, such as training which stimulates the production of power above 90% of Pmax (Pmax = maximal average concentric power output), is effective in enhancing the countermovement jump (CMJ) performance using the method of complex pairs or separate execution of the exercises in the complex pair (separate complex pair).METHODSThirty male students of the Faculty of Sports Studies were divided into 2 experimental (EX1, EX2) and 1 control group (CNTR). The experimental groups trained for 8 weeks using the complex training (CT) method twice a week with the same amount of repetitions for each exercise. The complex pair consisted of half-squat jumps with the intensity over 90% of Pmax and plyometric depth-jumps. EX1 trained using the complex pair method with the intracomplex rest interval of up to 15 seconds. EX2 trained all sets of the half-squat jumps first and then all sets of the plyometric exercise. We used non-parametric statistics and linear regression analysis to evaluate the effect on increasing the CMJ performance after the intervention program.RESULTSThere were no significant differences between the pre-test and post-test in any of the experimental groups (p &gt; 0.05), although there were significant differences between the weeks in EX1 and EX2 (p &lt; 0.05). The CMJ performance increased insignificantly (p &gt; 0.05) each week by 0.14 cm in EX1 and by 0.07 cm in EX2. CONCLUSIONThese results did not clearly show the application of the CT methods to be useful in enhancing the CMJ. In practice we recommend using the complex pairs to save training time and increase training intensity. However, an additional longer-term intervention experiment with a bigger sample size and groups randomized by the CMJ parameter (not by Pmax) is needed.

Eleven Years' Monitoring of the World's Most Successful Male Biathlete of the Last Decade.

To report the changes in the training characteristics, performance, and heart-rate variability (HRV) of the world's most successful male biathlete of the last decade. During the analyzed 11-year (2009-2019) period, the participant won 7 big crystal globes, corresponding to the winner of the International Biathlon Union World Cup. The training characteristics are reported as yearly volume (in hours) of low-intensity training (LIT), moderate- and high-intensity training, and speed and strength training. Performance was quantified by the number of World Cup top-3 positions per season. HRV was expressed as low- and high-frequency spectral power (in milliseconds squared), root-mean-square difference of successive R-R interval (in milliseconds), and heart rate (in beats per minute). The training volume increased from 530 to ∼700hours per year in 2009-2019, with a large polarization in training intensity distribution (ie,LIT 86.3% [2.9%]; moderate-intensity training 3.4% [1.5%]; high-intensity training 4.0% [0.7%]; strength 6.3% [1.6%]). The number of top-3 positions increased from 2 to 24-26 in 2009-2018 but decreased to 6 in 2019. The mean supine values in the root-mean-square difference of successive R-R interval and high-frequency spectral power divided by heart rate increased until 2015, which were stable over 2016-2018 but decreased in 2019. The number of top-3 positions was related to the total (r = .66, P = .02) and LIT (r = .92, P < .001) volume and to several markers of supine parasympathetic activity. The improvement in performance of the participant was mainly determined by the progressive increase in training volume, especially performed at low intensity, and was correlated to parasympathetic activity markers. This case study confirms the effectiveness of the training method, with a large amount of LIT in an elite endurance athlete, and of regular HRV monitoring.

Effects of Combined Surfaces vs. Single-Surface Plyometric Training on Soccer Players' Physical Fitness.

Ramirez-Campillo, R, Álvarez, C, García-Pinillos, F, García-Ramos, A, Loturco, I, Chaabene, H, and Granacher, U. Effects of combined surfaces vs. single-surface plyometric training on soccer players' physical fitness. J Strength Cond Res 34(9): 2644-2653, 2020-The aim of this study was to compare the effects of a 8-week plyometric jump training (PJT) performed on different surfaces (grass, land-dirt, sand, wood, gym mat, and tartan-track) vs. a single-surface PJT (grass) on components of physical fitness (muscle power, speed, and change-of-direction speed [CODS] tasks) and sport-specific performance (i.e., maximal kicking velocity [MKV]) in male soccer players aged 11-14 years. Athletes were randomly assigned to a combined surfaces PJT (PJTc, n = 8), a single-surface PJT (PJTs, n = 8), or an active control (CON, n = 7). Although the PJT group trained on grass, the PJTc trained on 6 different surfaces and equally distributed the total jump volume according to the surface. Pre-post tests were conducted on grass. Significant main effects of time were observed for the countermovement jump, the standing-long-jump, the 20-cm drop jump, 30-m sprint time, CODS, and MKV (all p < 0.001; d = 0.53-0.87). Group × time interactions were identified for all jump tests, MKV, 30-m sprint time, and CODS (all p < 0.001; d = 0.58-0.71) in favor of PJTc. No significant pre-post changes were observed in the CON (all p > 0.05; d = 0.07-0.1). In conclusion, PJT is effective in improving physical fitness in young soccer players when conducted in combination with regular soccer training. Although general fitness testing and PJTs were performed on grass, larger physical fitness improvements were found after PJTc. Thus, PJTc is recommended, as it provides a better overload stimulus compared with more conventional training overload (e.g., increase in training volume or intensity). Future studies still have to address the underlying physiological adaptations after PJTc.

Long Distance Triathlete With Iliac Endofibrosis

A 48 year old long distance triathlete complained of exercise induced thigh pain on the left side for several years. Physical examination in the presence of strongly palpable foot pulses was uneventful at rest, but there was a drop in ankle brachial index (ABI) to 0.4 after exercise. Magnetic resonance angiography (MRA) revealed a mild stenosis of the external iliac artery (EIA) on the left side (A). Through extraperitoneal access, a high grade stenosis became apparent (B). After vein patch plasty and an uneventful post-operative recovery, the athlete was able to increase training intensity free of pain.Image 1

Anodal transcranial direct current stimulation enhances strength training volume but not the force-velocity profile.

This study aimed to explore the acute effect of transcranial direct current stimulation (tDCS) on the force-velocity relationship, strength training volume, movement velocity, and ratings of perceived exertion. Fourteen healthy men (age 22.8 ± 3.0years) were randomly stimulated over the dorsolateral prefrontal cortex with either ANODAL, CATHODAL or SHAM tDCS for 15min at 2mA. The one-repetition maximum (1RM) and force-velocity relationship parameters were evaluated during the bench press exercise before and after receiving the tDCS. Subsequently, participants completed a resistance training session consisting of sets of five repetitions with 1min of inter-set rest against the 75%1RM until failure. No significant changes were observed in the 1RM or in the force-velocity relationship parameters (p ≥ 0.377). The number of repetitions was higher for the ANODAL compared to the CATHODAL (p = 0.025; ES = 0.37) and SHAM (p = 0.009; ES = 0.47) conditions. The reductions of movement velocity across sets were lower for the ANODAL than for the CATHODAL and SHAM condition (p = 0.014). RPE values were lower for the ANODAL compared to the CATHODAL (p = 0.119; ES = 0.33) and SHAM (p = 0.150; ES = 0.44) conditions. No significant differences between the CATHODAL and SHAM conditions were observed for any variable. The application of ANODAL tDCS before a resistance training session increased training volume, enabled the maintenance of higher movement velocities, and reduced RPE values. These results suggest that tDCS could be an effective method to enhance resistance-training performance.