Changes in repeated-sprint performance in relation to change in locomotor profile in highly-trained young soccer players

How to use changes in non soccer-specific locomotor entities (i.e., maximal aerobic and sprinting speeds) to predict changes in performance that is believed to be soccer specific (although I have my doubts too!)

Figure 1Buchheit, M. and Mendez-Villanueva, A., Changes in repeated-sprint performance in relation to change in locomotor profile in highly-trained young soccer players, J Sports Sci., 2014, In press

To examine the effects of changes in maximal aerobic (MAS) and sprinting (MSS) speeds, and the anaerobic reserve (ASR), on repeated-sprint performance, 270 highly-trained soccer players (14.5±1.6 yr) completed three times per season (over 5 years) a maximal incremental running test to approach MAS, a 40-m sprint with 10-m splits to assess MSS and a repeated-sprint test (10×30-m sprints), where best (RSb) and mean (RSm) sprint times, and percentage of speed decrement (%Dec) were calculated. ASR was calculated as MSS-MAS. While ∆RSb were related to ∆MSS and ∆body mass (r2=0.42, 90%CL[0.34;0.49] for the overall multiple regression, n=334), ∆RSm was also correlated with ∆MAS and ∆sum of 7 skinfolds (r2 =0.43 [0.35;0.50], n=334). ∆%Dec was related to ∆MAS (r2=0.02 [-0.07;0.11], n=334). Substantial ∆MSS and ∆MAS had a predictive value of 70 and 55% for ∆RSm, respectively. Finally, ∆ASR per se was not predictive of ∆RSm (Cohen’s = +0.8 to -0.3 with increased ASR), but the greater magnitude of ∆RSm improvement was observed when MSS, MAS and ASR increased together (0.8 vs. +0.4 with ASR increased vs. not, additionally to MSS and MAS). Low-cost field tests aimed at assessing maximal sprinting and aerobic speeds can be used to monitor ∆RS performance.

Key words: football association; repeated-sprint ability; maximal sprinting speed; maximal aerobic speed; anaerobic speed reserve

Physiological, psychometric and performance effects of the Christmas break in Australian Football

afccolourlogo-800x600Buchheit M, Morgan W, Wallace J, Bode M, and Poulos N. Physiological, psychometric and performance effects of the Christmas break in Australian Football, 2014, IJSPP, In press.

[Project initiated in November 2013 / data collected in December 2013-January-Feb 2014 / Paper submitted in March 2013 / Accepted 13th of April 2014 - Thanks IJSPP !]

Figure 2

Purpose. The aim of the present study was to quantify the physiological, psychometric and performance effects of a 2-week Christmas break in a professional Australian Football League (AFL) club.
Methods. A series of physiological (e.g., heart rate (HR) response to a 5-min submaximal run and skinfolds thickness), psychometric (rate of perceived exertion (RPE) responses and wellness variables) and performance (running activity during standardized handball games, isometric mid-thigh pull (IMTP) peak force and counter movement jump (CMJ) measures were conducted in the weeks before and after the break.
Results. There was a possible and small increase in the sum of the 7 skinfolds, whilst body mass and free fat mass remained possible and likely unchanged, respectively. Sleep and stress scores remained likely-to-almost certainly unchanged, but there were some small, possible-to-likely decreases in fatigue and soreness scores. HR and RPE responses to the 5-min submaximal run were likely slightly lower (i.e., improved) after the break. High-intensity running and acceleration distance during a standard handball game were very-likely slightly greater, while HR and RPE responses to the game were possibly-to-very likely unchanged. HR responses to a high-intensity training session remained very likely unchanged. There was also a likely small increase IMTP peak Force, but likely-to-very likely no change in CMJ variables.
Conclusions. Our results show that players returned from a 2-week break during pre-season well recovered, with preserved to improved levels of strength and cardiorespiratory fitness, despite small increases in skinfold thickness.

Key words: detraining; periodization; monitoring; heart rate; acceleration, iso-pull.
2013-11-29 14.10.26Follow @PoulosNick, @Willmorgan4 and @JarrydWallace7

Programming High-intensity Training in Handball

Based on the 2-part HIT review (I and II) on HIT programming with my mate Paul Laursen, I provide in this new paper some examples on how to practically implement HIT with players, and compare the performance benefits of different HIT formats in highly-trained Handball players. Many thanks to Aspetar Journal for the nice formatting too !

Pages from Buchheit - Programming High-intensity Training in Handball

 

Predicting changes in high-intensity intermittent running performance with acute responses to short jump rope workouts

Figures J Sport Sci & MedBuchheit M, Rabbani A and Taghi Beigi H. Predicting changes in high-intensity intermittent running performance with acute responses to short jump rope workouts in children. J Sport Sci & Med, 2014, In Press.

The aims of the present study were to 1) examine whether individual HR and RPE responses to a jump rope workout could be used to predict changes in high-intensity intermittent running performance in young athletes, and 2) examine the effect of using different methods to determine a smallest worthwhile change (SWC) on the interpretation of group-average and individual changes in the variables. Before and after an 8-week high-intensity training program, 13 children athletes (10.6±0.9 yr) performed a high-intensity running test (30-15 Intermittent Fitness Test, VIFT) and three jump rope workouts, where HR and RPE were collected. The SWC was defined as either 1/5th of the between-subjects standard deviation or the variable typical error (CV). After training, the large ≈9% improvement in VIFT was very likely, irrespective of the SWC. Standardized changes were greater for RPE (very likely-to-almost certain, ~30-60% changes, ~4-16 times > SWC) than for HR (likely-to-very likely, ~2-6% changes, ~1- 6 times >SWC) responses. Using the CV as the SWC lead to the smallest and greater changes for HR and RPE, respectively. The predictive value for individual performance changes tended to be better for HR (74-92%) than RPE (69%), and greater when using the CV as the SWC. The predictive value for no-performance change was low for both measures (<26%). Substantial decreases in HR and RPE responses to short jump rope workouts can predict substantial improvements in high-intensity running performance at the individual level. Using the CV of test measures as the SWC might be the better option.

Key words: submaximal heart rate; rate of perceived exertion; OMNI scale; 30-15 Intermittent Fitness Test; progressive statistics.

13 years and 4 PhDs later….

The paper just published in Frontiers in Physiology outlines the story of my ‘relationship’ with HRV. A bit like a rollercoaster, but with a happy ending!

Rome

I started to get interested in HRV as a training monitoring tool in 2001, when I came across the A. Hautala paper showing the HRV recovery time course following a 75-km cross-country skiing race – that was a revelation. I then started a PhD in France the same year, but actually found more limitations than applications if the field, which left me definitely disappointed. Fair enough, these efforts were nevertheless worthwhile since they allowed me to better understand the bases of the ‘HRV tool’, and I managed to do some progress with respect to the optimal ways for data collection and analysis. This was then followed by a first series of applied projects, more centered on acute interventions designed to better understand the mechanisms underlying parasympathetic reactivation post effort (Hani Al Haddad, PhD #2, our first child with HRV). Later, in parallel to the applied work that I conducted on my own and/or through different collaborations, and with my mates in Aspire in Qatar, I have been lucky enough to be involved in the design/supervision of 2 very applied PhDs (Jamie Stanley, PhD #3 in Australia and Dan Plews PhD #4 in New Zealand, the twins of the 2nd delivery). While most of these latter field studies were not the easiest to publish (reflecting again the issues of the publication process, please see other posts), they sealed the methodology to properly monitor athletes, both on a short- and long-term basis. Some of the key take home messages, which are still largely ignored by practitioners, were that HRV measures can’t be used in isolation and that a proper statistical methodology needs to be used – in practice people still collect data at random intervals and try to provide training recommendations based on direct changes in unreliable indices, and take the measures out of their context. I am not pretending (and will never) that our conclusions are flawless and that there is only one way to reach Rome, but I have today much more confidence in the process to apply with athletes, that I had 13 years ago. Fortunately enough, I didn’t quit HRV in 2004 when submitting my PhD work.  We had an uninterrupted series of story twists and surprises together, and since now I know her better, I am happy to grow old with her. For better, or worse! This review paper is dedicated to all the friends and colleagues who made our relationship so enjoyable and more exciting every day. Thank you all!

out-of-context3

@HaniAlHaddad2 @jstan85 @theplews1@PaulBLaursen

Moderate recovery unnecessary to sustain high stroke volume during interval training

IMG_20131125_081714Stanley J. & Buchheit M. Moderate recovery unnecessary to sustain high stroke volume during interval training, J Sport Sci & Med, 2014, In press.Recovery SV HIT

It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO2), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3 min work period, 2 min recovery) session on two occasions. VO2, HR and Qc were higher during moderate-intensity (60%) compared with low-intensity (30%) (VO2, effect size; ES=+2.6; HR, ES=+2.8; Qc, ES=+2.2) and passive (HR, ES=+2.2; Qc, ES=+1.7) recovery. By contrast, there were no clear differences in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES=−0.1; 30%, ES=−0.2). To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT.

Keywords: high-intensity interval training; cardiac output; cardiac function; arteriovenous oxygen difference

JamieFollow Jamie on twitter

Effects of age, maturity and body dimensions on match running performance in highly-trained under 15 soccer players

More vs less mature

Buchheit & Mendez-Villanueva. Effects of age, maturity and body dimensions on match running performance in highly-trained under 15 soccer players. Journal of Sports Science, In press

For a discussion about the stats used in this study see the comments here: don’t trust % differences

The aim of the present study was to compare, in 36 highly-trained under 15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n=115 player-files). Total distance and distance covered >16 km/h (D>16 km.h-1) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen’s d for MSS: 0.5-1.0, likely to almost certain) and match running performances (D>16 km.h-1: 0.2-0.5, possibly to likely) than their younger, less mature and/or smaller team-mates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures vs. match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players’ maturity status when assessing their on-field playing performance.

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Litterature on validation and various use: 032A-VO2000 U of MN validation 032B-VO2000 U of MI validation 033-VO2000 U of Mass validation Byard-VO2000UofMValidationStudy Data Sheet VO2000 M. Buchheit – Parasympathetic reactivation after repeated sprint exercise VO2000 Portable VO2 testing..

contact: mb(at)martin-buchheit.net

Changes of direction during high-intensity intermittent runs: neuromuscular and metabolic responses

Karim Hader, Alberto Mendez-Villanueva, Said Ahmaidi, Ben Williams and Martin
Buchheit. Changes of direction during high-intensity intermittent runs: neuromuscular and metabolic  responses. Accepted to BMC Sports Science, Medicine and Rehabilitation on 19 December 2013.

Abstract
Background: The ability to sustain brief high-intensity intermittent efforts (HIE) is meant to be a major attribute for performance in team sports. Adding changes of direction to HIE is believed to increase the specificity of training drills with respect to game demands. The aim of this study was to investigate the influence of 90°-changes of direction (COD) during HIE on metabolic and neuromuscular responses.
Methods: Eleven male, team sport players (30.5±3.6 y, 81±6 kg, 180± 6cm) performed randomly HIE without (straight-line, 2x[10x 22m]) or with (2x[10x ~16.5m]) two 90°-COD. To account for the time lost while changing direction, the distance for COD runs during HIE was individually adjusted using the ratio between straight-line and COD sprints. Players also performed 2 countermovement (CMJ) and 2 drop (DJ) jumps, during and post HIE. Pulmonary oxygen uptake ( O2), quadriceps and hamstring oxygenation, blood lactate concentration (Δ[La]b), electromyography amplitude (RMS) of eight lower limb muscles and rating of perceived exertion (RPE) were measured for each condition.
Results: During HIE, CODs had no substantial effects on changes in  O2, oxygenation, CMJ and DJ performance and RPE (all differences in the changes rated as unclear). Conversely, compared with straight-line runs, COD-runs were associated with a possibly higher Δ[La]b (+9.7±10.4%, with chances for greater/similar/lower values of 57/42/0%). There was also a lower decrease in lateral gastrocnemius (-8.5±9.3%, 1/21/78) and semitendinosus (-11.9 ± 14.6%, 2/13/85) electromyography amplitude; the decrease in electromyography amplitude for the other muscles was not clearly different.
Conclusion: Adding two 90°-CODs on adjusted distance during two sets of HIE is likely to elicit equivalent decreases in CMJ and DJ height, and similar cardiorespiratory and perceptual responses, despite a lower average running speed. A fatigue-induced modification in lower limb control observed with CODs may have elicited a selective reduction of electromyography activity in hamstring muscles and may induce, in turn, a potential mechanical loss of knee stability. Therefore, changing direction during HIE might be an effective training practice 1) to manipulate some components of the acute physiological load of HIE, 2) to promote long-term COD-specific neuromuscular adaptations aimed at improving performance and knee joint stability.
Key Words: cardiorespiratory responses; neuromuscular adjustment; selective activation; knee stabilization.

Full paper available on the Journal Website (open Access)