Akenhead, R, Harley, J, and Tweddle, S. Examining the external training load of an English Premier League football team with special reference to acceleration. J Strength Cond Res 30(9): 2424-2432, 2016-Practitioners and coaches often use external training load variables such as distance run and the number of high-speed running (HSR) activities to quantify football training. However, an important component of the external load may be overlooked when acceleration activities are not considered. The aim of this study was to describe the within-microcycle distribution of external load, including acceleration, during in-season 1-game weeks in an elite football team. Global Positioning System technology was used to collect time-motion data from 12 representative 7-day microcycles across a competitive season (48 training days, 295 data sets). Training time, total distance (TD), high-speed running (HSR) distance (>5.8 m·s), sprint running distance (>6.7 m·s) and acceleration variables were recorded during each training session. Data were analysed for interday and interposition differences using mixed linear modeling. The distribution of external load was characterized by the second training day of the microcycle (5 days prematch) exhibiting the highest values for all variables of training load, with the fourth day (1 day prematch) exhibiting the lowest values. Central midfield players covered ∼8-16% greater TD than other positions excluding wide midfielders (p ≤ 0.03, d = 0.2-0.4) and covered ∼17% greater distance accelerating 1-2 m·s than central defenders (p = 0.03, d = 0.7). When expressed relative to training duration and TD, the magnitude of interday and interposition differences were markedly reduced (p = 0.03, d = 0.2-0.3). When managing the distribution of training load, practitioners should be aware of the intensity of training sessions and consider the density of external load within sessions.

The aim of this study was to quantify the motion demands of match-play in elite U12-U16 year old soccer players. 112 players from two professional soccer clubs at five age-group levels (U12-U16) were monitored during competitive matches (n = 14) using 5 Hz non-differential Global Positioning System (NdGPS). Velocity thresholds were normalised for each age-group using the mean squad times for a flying 10 m sprint test as a reference point. Match performance was reported as total distance, high-intensity distance, very high-intensity distance and sprint distance.Data were reported both in absolute (m) and relative (m · min -1 ) terms due to a rolling substitute policy. U15 (1.35 ± 0.09 s) and U16 (1.31 ± 0.06 s) players were significantly quicker than the U12 (1.58 ± 0.10 s), U13 (1.52 ± 0.07 s) and U14 (1.51 ± 0.08 s) players in the flying 10m sprint test (P<0.001). The U16 age-group covered significantly more absolute total distance (U16 > U12, U13, U14), high-intensity distance (U16 > U12, U13, U14, U15), very high-intensity distance (U16 > U12, U13) and sprint distance (U16 > U12, U13) than their younger counterparts (P<0.05). When the data are considered relative to match exposure, few differences are apparent. Training prescription for youth soccer players should consider the specific demands of competitive match-play at each age-group.

This study investigated the acute changes in body composition that occur over the course of a competitive season in elite rugby league players. Twenty elite senior players from an English Super League rugby league team underwent a total-body dual-energy x-ray absorptiometry scan at three phases of a competitive season: preseason (February), mid-season (June) and post-season (September). Body mass, fat mass, lean mass, percentage body fat and bone mineral content were reported at each phase. Between the start and mid-point of the season, body mass, lean mass, fat mass and body fat percentage showed no significant change (p>0.05), however bone mineral content was significantly increased (+0.71%; 30.70 ± 38.00g; p<0.05). Between the mid-season and post-season phase, body mass and bone mineral content showed no significant change (p>0.05), however significant changes were observed in lean mass (-1.54%; 1.19 ± 1.43kg), fat mass (+4.09%; 0.57 ± 1.10kg) and body fat percentage (+4.98%; 0.78 ± 1.09%; p<0.05). The significant changes in body composition seen over the latter stages of the competitive season may have implications for performance capabilities at this important stage of competition. An increase in fat mass and decrease in lean mass may have a negative effect on the power/body mass ratio, and therefore may be a cause for concern for playing, coaching and medical staff.

The data demonstrate the potential to tax the anaerobic energy system to different extents using speed-endurance SSGs and that SSGs elicit greater acceleration/ deceleration load than generic running drills.