The development of functional overreaching is associated with a faster heart rate recovery in endurance athletes

Aubry A, Hausswirth C, Louis J, Coutts AJ, Buchheit M & Le Meur Y. The development of functional overreaching is associated with a faster heart rate recovery in endurance athletes. Plos1, In press.

Purpose: The aim of the study was to investigate whether heart rate recovery (HRR)
may represent an effective marker of functional overreaching (f-OR) in endurance
athletes. Methods and Results: Thirty-one experienced male triathletes were tested (10
control and 21 overload subjects) before (Pre), and immediately after an overload
training period (Mid) and after a 2-week taper (Post). Physiological responses were
assessed during an incremental cycling protocol to exhaustion, including heart rate,
catecholamine release and blood lactate concentration. Ten participants from the
overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% decreased
performance with concomitant high perceived fatigue). Additionally, only the f-OR
group demonstrated a 99% chance to demonstrate an increase in HRR during the
overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed
a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine
(-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%,
moderate). These blood measures returned to baseline levels at Post. HRR change
was negatively correlated to changes in performance, peak HR and peak blood
metabolites concentrations. Conclusion: These findings suggest that i) a faster HRR is
not systematically associated with improved physical performance, ii) changes in HRR
should be interpreted in the context of the specific training phase, the athletes
perceived level of fatigue and the performance response; and, iii) the faster HRR
associated with f-OR may be induced by a decreased central command and by a lower
chemoreflex activity.

Fig2CTL: controls; AF: acute fatigue; f-OR: functional overreaching.

 Anael   julien  Xtof

Aaron  Yann

Quantification of training and competition load across a season in an elite Australian Football Club

Ritchie D, Hopkins WG, Buchheit M, Cordy J, & Bartlett JD. Quantification of training and competition load across a season in an elite Australian Football Club. IJSPP, In press.

Figure 1Full text here


Purpose: Load monitoring in Australian Football (AF) has been widely adopted, yet team sport periodization strategies are relatively unknown. Here we have aimed to quantify training and competition load across a season in an elite AF team, using rating of perceived exertion (RPE) and GPS. tracking.

Methods: Weekly totals for RPE and GPS loads (including accelerometer data; Playerload) were obtained for 44 players across a full season for each training modality and for competition. General linear mixed models compared mean weekly load between 3x pre-season and 4x in-season blocks. Effects were assessed with inferences about magnitudes standardized with between-player SD.

Results: Total RPE load was most likely greater during pre-season, where the majority of load was obtained via skills and conditioning. There was a large reduction in RPE load in the last pre-season block. During in-season, half the total load came from games and the remaining half from training, predominantly skills and upper-body weights. Total distance, high-intensity running, and Playerload showed large to very large reductions from pre-season to in-season, whereas changes in mean speed were trivial across all blocks. All these effects were clear at the 99% level.

Conclusions: These data provide useful information about targeted periods of loading and unloading across different stages of a season. Our study also provides a framework for further investigation of training periodization in AF teams.

Key Words: Training organisation, training distribution, team sports

mG85mk-j_400x400  xOtMcx1U_400x400

@DeanRitchie26     @JonBartlett66

Heart rate-based versus speed-based high-intensity interval training in young soccer players

Rabbani and M. Buchheit. Heart rate-based versus speed-based high-intensity interval training in young soccer players. International Research in Science and Soccer II, 2015, In press

Full text here

HR vs Speed based HIT


While heart rate (HR) is often used to control exercise intensity during high-intensity interval training (HIT), this approach has several limitations, including the difficulty for practitioners to regulate running intensity. To overcome these limitations, using the speed reached at the end of the 30-15 Intermittent Fitness Test (VIFT) as the reference for running intensity has been suggested. The aim of the present study was to compare the effect of HR- vs. VIFT-based HIT on high-intensity intermittent running performance in young soccer players. Twenty two soccer players (15.12 ± 0.5 yrs) were divided in two different experimental groups including HR-based (n=10) or VIFT-based (n=12) HIT during their preseason preparation. The VIFT-based HIT group performed a 30-15 Intermittent Fitness Test before the intervention to detect player’s VIFT. All players performed a Yo-Yo Intermittent Recovery Test level 1 (YYIRT1) before and after the intervention. All players underwent the same conditioning and technical/tactical training programs for 4-5 weeks, except the method of individualizing soccer-specific HIT sessions with the ball (2 sessions of HIT=3 sets of 3:30 min): either according to 90-95% of maximal HR, or 65-70% VIFT. We then compared the between-group differences in weekly improvement in YYIRT1 using magnitude-based inferences. VIFT-based HIT produced likely greater weekly improvement in YYIRT1performance than HR-based HIT (+86%, 90%CL (1.5- 240%); standardized difference: +0.7(0.02- 1.40), chances for greater/similar/lower values of 95/4/1). Using VIFT as a reference speed for HIT programming may elicit greater high-intensity intermittent running performance improvements than using percentages of maximal HR in young soccer players.

Key words: high-intensity running programming; training individualization; high-intensity running performance; 30-15 Intermittent Fitness Test.



Assessing stride variables and vertical stiffness with GPS-embedded accelerometers: preliminary insights for the monitoring of neuromuscular fatigue on the field

Buchheit, M., Gray, A., and Morin J.B. Assessing stride variables and vertical stiffness with GPS-embedded accelerometers: preliminary insights for the monitoring of neuromuscular fatigue on the field. Journal of Sports Science & Medicine, In press, 2015


Full text


The aim of the present study was to examine the ability of a GPS-imbedded accelerometer to assess stride variables and vertical stiffness (K), which are directly related to neuromuscular fatigue during field-based high-intensity runs. The ability to detect stride imbalances was also examined. A team sport player performed a series of 30-s runs on an instrumented treadmill (6 runs at 10, 17 and 24 km/h) with or without his right ankle tapped (aimed at creating a stride imbalance), while wearing on his back a commercially-available GPS unit with an embedded 100-Hz tri-axial accelerometer. Contact (CT) and flying (FT) time, and K were computed from both treadmill and accelerometers (Athletic Data Innovations) data. The agreement between treadmill (criterion measure) and accelerometer-derived data was examined. We also compared the ability of the different systems to detect the stride imbalance. Biases were small (CT and K) and moderate (FT). The typical error of the estimate was trivial (CT), small (K) and moderate (FT), with nearly perfect (CT and K) and large (FT) correlations for treadmill vs. accelerometer. The tape induced very large increase in the right – left foot ∆ in CT, FT and K measured by the treadmill. The tape effect on CT and K ∆ measured with the accelerometers were also very large, but of lower magnitude than with the treadmill. The tape effect on accelerometer-derived ∆ FT was unclear. Present data highlight the potential of a GPS-embedded accelerometer to assess CT and K during ground running.

Keywords: movement tracking; fatigue monitoring; 

Monitoring locomotor load in soccer: is metabolic power, powerful?

Buchheit M, Manouvrier C, Cassirame J and Morin JB. Monitoring locomotor load in soccer: is metabolic power, powerful? Int J Sport Med, In press, 2015.

 Full text here 

MetabonotpowerulFigure 1. Oxygen uptake (VO2), speed and metabolic power estimated from locomotor demands (PGPS) during the warm-up and the 3 exercise bouts in a representative player. VO2max: maximal oxygen uptake reached during an incremental test to exhaustion.

Interview – discussion podcast on the paper here 



The aim of the present study was to examine the validity and reliability of metabolic power (P) estimated from locomotor demands during soccer-specific drills. Fourteen highly-trained young soccer players (15.4±1.6 yr) performed a soccer-specific circuit with the ball (3 x 1-min bouts, interspersed with 30-s passive recovery) on two different occasions. Locomotor activity was monitored with 4-Hz GPS units, while oxygen update (VO2) was collected with a portable gas analyzer. P was calculated using either net VO2 responses and traditional calorimetry principles (PVO2, or locomotor demands (PGPS, Distance covered into different speed, acceleration and P zones was recorded. Players covered 30 times more distance >20 W/kg (PGPS) than >14.4 km.h-1. While PGPS was 29 ± 10 % lower than PVO2 (Cohen’s d<-3) during the exercise bouts, it was 85 ± 7 % lower (d<-8) during recovery phases. The typical error of the estimate between PGPS vs PVO2 was moderate: 19.8%, 90% confidence limits: (18.4;21.6). The correlation between both estimates of P was small: 0.24 (0.14;0.33). Very large day-to-day variations were observed for acceleration, deceleration and >20 distances (all CVs >50%), while total distance, average PVO2 and PGPS showed CVs <10%. ICC ranged from very low- (acceleration and >20 distances) to-very high (PVO2). To conclude, PGPS largely underestimates the energy demands of soccer-specific drills, especially during the recovery phases. Together with its moderate agreement with calorimetry-related P estimations, the poor reliability of PGPS >20 questions its value for monitoring purposes in soccer.

Key words: soccer, acceleration, deceleration, energy demands, soccer-specific, training load.

Change of direction speed in soccer: How much braking is enough?

Hader K, Palazzi D and Buchheit M. Change of direction speed in soccer: How much braking is enough? Kinesiology 47(2015) 1:44-52

Full text here


Figure 1. Running speed during 20-m sprints with (45º and 90º) or without (straight line, SL) change of direction. The grey area represents the change of direction.



The aims of the present study were to examine 1) the validity and reliability of a new timing system to assess running kinematics during change of direction (COD), and 2) the determinants of COD-speed. Twelve young soccer players performed three 20-m sprints, either in straight line or with one 45º- or 90º-COD. Sprints were monitored using timing gates and two synchronized 100-Hz laser guns, to track players’ velocities before, during and after the COD. The validity analysis revealed trivial-to-small biases and smallto-moderate typical errors of the estimate with the lasers compared with the timing gates. The reliability was variable-dependent, with trivial- (distance at peak speed) to-large (distance at peak deceleration) typical errors. Kinematic variables were angle-dependent, with likely lower peak speed, almost-certainly slower minimum speed during the COD and almost-certainly greater deceleration reached for 90º-COD vs. 45º-COD sprints. The minimum speed during the COD was largely correlated with sprint performance for both sprint angles. Correlations with most of the other independent variables were unclear. The new timing system showed acceptable levels of validity and reliability to assess some of the selected running kinematics during COD sprints. The ability to maintain a high speed during the COD may be the determinant for COD-speed.

Key words: acceleration, deceleration, speed profile, sprint, laser gun, soccer

Psychometric and physiological responses to a pre-season competitive camp in the heat with a 6-hr time difference in elite soccer players

Buchheit, M., Cholley Y. and Lambert P. Psychometric and physiological responses to a pre-season competitive camp in the heat with a 6-hr time difference in elite soccer players. IJSPP, In press.

Purpose. The aim of the present study was to examine in elite soccer players some psychometric and physiological responses to a competitive camp in the heat, after travelling across 6 time-zones. Methods. Data from 12 elite professional players (24.6±5.3 yr) were analyzed. They participated in an 8-day pre-season summer training camp in Asia (heat index 34.9±2.4 ⁰C). Players’ activity was collected during all training sessions and the friendly game using 15-Hz GPS. Perceived training/playing load was estimated using session rate of perceived exertion (RPE) and training/match duration. Psychometric measures of wellness were collected upon awakening before, during and after the camp using simple questionnaires. HR response to a submaximal 4-min run (12 km/h) and the ratio between velocity and force load (accelerometer-derived measure, a marker of neuromuscular efficiency) response to 4 ~60-m runs (22-24 km/h) were collected before, at the end and after the camp. Results. After a large increase, the RPE/m.min-1 ratio decreased substantially throughout the camp. There were possible small increases in perceived fatigue and small decreases in subjective sleep quality on the 6th day. There were also likely moderate (~3%) decreases in HR response to the submaximal run, both at the end and after the camp, which were contemporary to possible small (~8%) and most-likely moderate (~19%) improvements in neuromuscular efficiency, respectively. Conclusions. Despite transient increases in fatigue and reduced subjective sleep quality by the end of the camp, these elite players showed clear signs of heat acclimatization, which were associated with improved cardiovascular fitness and neuromuscular running efficiency.

Fig 1 final color2

Figure 1. Upper panel: change in locomotor load (measured via GPS) and heat index before, during and after the Asian camp. The flights represent the different flying trips, with their specific duration indicated into brackets. As wearing GPS was not allowed during the official match, the total distance covered was extrapolated from historical club data (Team A) against Team B for illustration. The timing of the monitoring sessions is also indicated, with Run standing for the submaximal run and the 4 60-m runs, and Wellness for the psychometric questionnaires. Lower panel: changes in perceived training load (rate of perceived exertion, RPE, method) and the RPE/distance per min ratio. The gray area represents the Hong Kong (HK) camp, while the grey and shaded area represents the time spent in Beijing. ****: very likely different vs. pre camp.

Keywords: heart rate monitoring, wellness, neuromuscular efficiency, association football, heat training.

A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players.

Deprez D, Buchheit M, Fransen J, Pion J, Lenoir M, Philippaerts RM, Vaeyens R.. A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players. J Sports Sci Med. 2015 May 8;14(2):418-26. eCollection 2015 Jun

Full text here

We investigated the evolution and stability of anthropometric and soccer-specific endurance characteristics of 42 high-level, pubertal soccer players with high, average and low yo-yo intermittent recovery test level 1 (YYIR1) baseline performances over two and four years. The rates of improvement were calculated for each performance group, and intra-class correlations were used to verify short- and long-term stability. The main finding was that after two and four years, the magnitudes of the differences at baseline were reduced, although players with high YYIR1 baseline performance still covered the largest distance (e.g., low from 703 m to 2126 m; high from 1503 m to 2434 m over four years). Furthermore, the YYIR1 showed a high stability over two years (ICC = 0.76) and a moderate stability over four years (ICC = 0.59), due to large intra-individual differences in YYIR1 performances over time. Anthropometric measures showed very high stability (ICCs between 0.94 to 0.97) over a two-year period, in comparison with a moderate stability (ICCs between 0.57 and 0.75) over four years. These results confirm the moderate-to-high stability of high-intensity running performance in young soccer players, and suggest that the longer the follow-up, the lower the ability to predict player’s future potential in running performance. They also show that with growth and maturation, poor performers might only partially catch up their fitter counterparts between 12 and 16 years. Key pointsYoung, high-level soccer players with a relatively low intermittent-endurance capacity are capable to catch up with their better performing peers after four years.Individual development and improvements of anthropometric and physical characteristics should be considered when evaluating young soccer players.


Football; field test; high-intensity intermittent performance; maturity status; talent development

Monitoring fatigue during the in-season competitive phase in elite soccer players

Thorpe RT, AJ. Strudwick, M. Buchheit, G. Atkinson, B. Drust, W. Gregson. Monitoring fatigue during the in-season competitive phase in elite soccer players. IJSPP 2015, In press.

IJSPP MAnUFigure 1. Mean (SD) total high-intensity (THIR, >14.4 km/h) distance (m), perceived ratings of fatigue (AU), countermovement jump (cm) and Ln rMSSD (ms) during the 17-day period

Purpose To quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17-days).
Methods Total high-intensity running distance (THIR), perceived ratings of wellness (fatigue, muscle soreness, sleep quality), counter-movement jump height (CMJ), post
exercise heart rate recovery (HRR) and heart rate variability (Ln rMSSD) were analysed during an in-season competitive period (17 days). General linear models were used to evaluate the influence of daily fluctuation in THIR distance (>14.4 km/h) on potential fatigue variables.
Results Fluctuations in fatigue (r=-0.51; large; P<0.001), Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were significantly correlated with fluctuations in THIR distance. Correlations between variability in muscle soreness, sleep quality and HRR and THIR distance were negligible and not statistically significant.
Conclusions Perceived ratings of fatigue and heart rate variability were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these particular markers show particular promise as simple, non-invasive assessments of fatigue status in elite soccer players during a short in-season competitive phase.

Key Words Training load, Performance, Recovery, Wellness


Peak match speed and maximal sprinting speed in young soccer players: effect of age and playing position

Hani Al Haddad, Ben M. Simpson, Martin Buchheit, Valter Di Salvo and Alberto Mendez-Villanueva. Peak match speed and maximal sprinting speed in young soccer players: effect of age and playing position. IJSPP, 2015, In press.

Figure 1Figure 1. Data are presented as mean and 90% confidence interval for maximal sprinting speed (MSS, white circles), peak match speed (PMSAbs, gray circles) and PMSAbs as percentage of MSS (PMSRel, black circles).


In this study we assessed the relationship between peak match speed (PMS) and maximal sprinting speed in regard to age and playing positions. Maximal sprinting speed and absolute PMS (PMSAbs) were collected from 180 male youth soccer players (U13 to U17, 15.0 ± 1.2 yrs, 161.5 ± 9.2 cm and 48.3 ± 8.7 kg). The fastest 10-m split over a 40-m sprint was used to determine maximal sprinting speed. PMSAbs was recorded using a global positioning system and was also expressed as a percentage of maximal sprinting speed (PMSRel). Sprint data were compared between age groups and between playing positions. Results showed that regardless of age and playing positions, faster players were likely to reach higher PMSAbs and possibly lower PMSRel. Despite a lower PMSAbs compared with older groups (e.g., 23.4 ± 1.8 vs. 26.8 ± 1.9 km/h for U13 and U17, respectively, ES= 1.9 90% confidence limits (1.6;2.1)), younger players reached a greater PMSRel (92.0±6.3% vs. 87.2±5.7% for U13 and U17, respectively, ES= -0.8 90% CL (-1.0; -0.5)). Playing position also affected PMSAbs and PMSRel, as strikers were likely to reach higher PMSAbs (e.g., 27.0 ± 2.7 vs. 23.6 ± 2.2 km/h for strikers and central midfielder, respectively, ES= 2.0 (1.7;2.2)) and PMSRel (e.g., 93.6 ± 5.2% vs. 85.3 ± 6.5% for striker and central midfielder, respectively, ES= 1.0 (0.7;1.3)) compared with all other positions. Present findings confirm that age and playing positions affect the absolute and relative intensity of speed-related actions during matches.

Key words: youth players, soccer, sprinting speed, playing position

@HaniAlHaddad2 @benMsimpson