Purpose: Competitive match play is a dominant component of the physical load completed by soccer players in a training microcycle. Characterizing the temporal disruption in homeostasis that follows exercise may provide some insight on the potential for match play to elicit an adaptive response. Methods: Countermovement-jump (CMJ) performance was characterized 3 d postmatch for 15 outfield players from an English Premier League soccer team (age 25.8 ± 4.1 y, stature 1.78 ± 0.08 m, body mass: 71.7 ± 9.1 kg) across a season. These players were classified as either starters (n = 9) or nonstarters (n = 6), according to their average individual playing time (more or less than 60 min/match). Linear mixed models were used to investigate the influence of indicators of match activity (total distance covered [TD] and high-intensity running distance [HI]) on CMJ height and peak power (PP). Results: Starting players covered much greater TD (ES = 1.5) and HI (ES = 1.4) than nonstarters. Furthermore, there was a possible positive effect of HI on CMJ height and PP. This relationship suggests that an additional 0.6 km of HI would increase CMJ height and PP by slightly more than the smallest-worthwhile-change values of 0.6 cm and 1.0 W/kg, respectively. This small yet practically relevant increase in performance may suggest that match play, more specifically the intense activities that are associated with the match, provides a physiological stimulus for neuromuscular adaptation. Conclusions: These data may have implications for the preparation of soccer squads, especially the training requirements of starting and nonstarting players.
Ryland Morgans, Rocco Di Michele, and Barry Drust
James J. Malone, Rocco Di Michele, Ryland Morgans, Darren Burgess, James P. Morton, and Barry Drust
To quantify the seasonal training load completed by professional soccer players of the English Premier League.
Thirty players were sampled (using GPS, heart rate, and rating of perceived exertion [RPE]) during the daily training sessions of the 2011–12 preseason and in-season period. Preseason data were analyzed across 6 × 1-wk microcycles. In-season data were analyzed across 6 × 6-wk mesocycle blocks and 3 × 1-wk microcycles at start, midpoint, and end-time points. Data were also analyzed with respect to number of days before a match.
Typical daily training load (ie, total distance, high-speed distance, percent maximal heart rate [%HRmax], RPE load) did not differ during each week of the preseason phase. However, daily total distance covered was 1304 (95% CI 434–2174) m greater in the 1st mesocycle than in the 6th. %HRmax values were also greater (3.3%, 1.3−5.4%) in the 3rd mesocycle than in the first. Furthermore, training load was lower on the day before match (MD-1) than 2 (MD-2) to 5 (MD-5) d before a match, although no difference was apparent between these latter time points.
The authors provide the 1st report of seasonal training load in elite soccer players and observed that periodization of training load was typically confined to MD-1 (regardless of mesocycle), whereas no differences were apparent during MD-2 to MD-5. Future studies should evaluate whether this loading and periodization are facilitative of optimal training adaptations and match-day performance.
Ryland Morgans, Adam Owen, Dominic Doran, Barry Drust, and James P. Morton
To monitor resting salivary secretory immunoglobulin A (SIgA) levels in international soccer players during the short-term training period that precedes international match play.
In a repeated-measure design, saliva samples were obtained from 13 outfield soccer players who participated in the training camps preceding 7 games (5 home and 2 away) of the 2014 FIFA World Cup qualifying campaign. Samples were obtained daily for 4 d preceding each game (and analyzed for SIgA using the IPRO oral-fluid-collection system) at match day minus 1 (MD-1), minus 2 (MD-2), minus 3 (MD-3), and minus 4 (MD-4).
SIgA displayed a progressive decline (P = .01) during the 4-d training period (MD-4, 365 ± 127 μg/mL; MD-3, 348 ± 154 μg/mL; MD-2, 290 ± 138 μg/mL; MD-1, 256 ± 90 μg/mL) such that MD-1 values were significantly lower (P = .01) than both MD-4 and MD-3. The 95% confidence intervals for the differences between MD-1 and MD-4 were –191 to –26 and between MD-1 and MD-3 were –155 to –28.
Data demonstrate that a short-term soccer-training camp in preparation for international competition induces detectable perturbations to mucosal immunity. Future studies should monitor SIgA (as a practical and noninvasive measure of immunity) alongside internal and external measures of training load in an attempt to strategically individualize training and nutritional strategies that may support optimal preparation for high-level competition.
Conall F. Murtagh, Christopher Nulty, Jos Vanrenterghem, Andrew O’Boyle, Ryland Morgans, Barry Drust, and Robert M. Erskine
Purpose: To investigate differences in neuromuscular factors between elite and nonelite players and to establish which factors underpin direction-specific unilateral jump performance. Methods: Elite (n = 23; age, 18.1 [1.0] y; body mass index, 23.1 [1.8] kg·m−2) and nonelite (n = 20; age, 22.3 [2.7] y; body mass index, 23.8 [1.8] kg·m−2) soccer players performed 3 unilateral countermovement jumps (CMJs) on a force platform in the vertical, horizontal-forward, and medial directions. Knee extension isometric maximum voluntary contraction torque was assessed using isokinetic dynamometry. Vastus lateralis fascicle length, angle of pennation, quadriceps femoris muscle volume (M vol), and physiological cross-sectional area (PCSA) were assessed using ultrasonography. Vastus lateralis activation was assessed using electromyography. Results: Elite soccer players presented greater knee extensor isometric maximum voluntary contraction torque (365.7 [66.6] vs 320.1 [62.6] N·m; P = .045), M vol (2853  vs 2429  cm3; P = .001), and PCSA (227  vs 193  cm2; P = .003) than nonelite. In both cohorts, unilateral vertical and unilateral medial CMJ performance correlated with M vol and PCSA (r ≥ .310, P ≤ .043). In elite soccer players, unilateral vertical and unilateral medial CMJ performance correlated with upward phase vastus lateralis activation and angle of pennation (r ≥ .478, P ≤ .028). Unilateral horizontal-forward CMJ peak vertical power did not correlate with any measure of muscle size or activation but correlated inversely with angle of pennation (r = −.413, P = .037). Conclusions: While larger and stronger quadriceps differentiated elite from nonelite players, relationships between neuromuscular factors and unilateral jump performance were shown to be direction-specific. These findings support a notion that improving direction-specific muscular power in soccer requires improving a distinct neuromuscular profile.
Liam Anderson, Patrick Orme, Rocco Di Michele, Graeme L. Close, Jordan Milsom, Ryland Morgans, Barry Drust, and James P. Morton
To quantify the accumulative training and match load during an annual season in English Premier League soccer players classified as starters (n = 8, started ≥60% of games), fringe players (n = 7, started 30–60% of games) and nonstarters (n = 4, started <30% of games).
Players were monitored during all training sessions and games completed in the 2013–14 season with load quantified using global positioning system and Prozone technology, respectively.
When including both training and matches, total duration of activity (10,678 ± 916, 9955 ± 947, 10,136 ± 847 min; P = .50) and distance covered (816.2 ± 92.5, 733.8 ± 99.4, 691.2 ± 71.5 km; P = .16) were not different between starters, fringe players, and nonstarters, respectively. However, starters completed more (all P < .01) distance running at 14.4–19.8 km/h (91.8 ± 16.3 vs 58.0 ± 3.9 km; effect size [ES] = 2.5), high-speed running at 19.9–25.1 km/h (35.0 ± 8.2 vs 18.6 ± 4.3 km; ES = 2.3), and sprinting at >25.2 km/h (11.2 ± 4.2 vs 2.9 ± 1.2 km; ES = 2.3) than nonstarters. In addition, starters also completed more sprinting (P < .01, ES = 2.0) than fringe players, who accumulated 4.5 ± 1.8 km. Such differences in total high-intensity physical work done were reflective of differences in actual game time between playing groups as opposed to differences in high-intensity loading patterns during training sessions.
Unlike total seasonal volume of training (ie, total distance and duration), seasonal high-intensity loading patterns are dependent on players’ match starting status, thereby having potential implications for training program design.
Liam Anderson, Graeme L. Close, Ryland Morgans, Catherine Hambly, John Roger Speakman, Barry Drust, and James P. Morton
Purpose: To better understand the energy and carbohydrate (CHO) requirements of a professional goalkeeper (GK) in elite soccer, the authors quantified physical loading, energy expenditure (EE), and energy intake (EI) during a 2-games-per-week in-season microcycle. Methods: Daily training and match loads were assessed in a professional GK (age 26 y, height 191 cm, body mass 85.6 kg) from the English Premier League using global positioning systems (GPS) and ProZone®, respectively. Assessments of EE (using the doubly labeled water method) and EI (using food diaries supported by the remote food photographic method and 24-h recalls) were also completed. Results: Physical loading was greater on match days than training days as inferred from total distance (4574  vs 1959  m), average speed (48  vs 40  m/min), and distance completed when jogging (993  vs 645  m) and running (138  vs 21  m). Average daily energy and macronutrient intake appear reflective of a self-selected “low-CHO” diet (energy 3160  kcal, CHO 2.6 [0.6], protein 2.4 [0.4], fat 1.9 [0.3] g/kg body mass). Mean daily EE was 2894 kcal. Conclusions: The average daily EE of this professional GK was approximately 600 kcal/d lower than that previously reported in outfield players from the same team. Such data suggest that the nutritional requirements of a GK should be carefully considered depending on the required daily and weekly loading patterns.
Robert J. Naughton, Barry Drust, Andy O’Boyle, Ryland Morgans, Julie Abayomi, Ian G. Davies, James P. Morton, and Elizabeth Mahon
While traditional approaches to dietary analysis in athletes have focused on total daily energy and macronutrient intake, it is now thought that daily distribution of these parameters can also influence training adaptations. Using 7-day food diaries, we quantified the total daily macronutrient intake and distribution in elite youth soccer players from the English Premier League in U18 (n = 13), U15/16 (n = 25) and U13/14 squads (n = 21). Total energy (43.1 ± 10.3, 32.6 ± 7.9, 28.1 ± 6.8 kcal·kg-1·day-1), CHO (6 ± 1.2, 4.7 ± 1.4, 3.2 ± 1.3 g·kg- 1·day-1) and fat (1.3 ± 0.5, 0.9 ± 0.3, 0.9 ± 0.3 g·kg-1·day-1) intake exhibited hierarchical differences (p < .05) such that U13/14 > U15/16 > U18. In addition, CHO intake in U18s was lower (p < .05) at breakfast, dinner and snacks when compared with both squads but no differences were apparent at lunch. Furthermore, the U15/16s reported lower relative daily protein intake than the U13/14s and U18s (1.6 ± 0.3 vs. 2.2 ± 0.5, 2.0 ± 0.3 g·kg-1). A skewed distribution (p < .05) of daily protein intake was observed in all squads, with a hierarchical order of dinner (~0.6 g·kg-1) > lunch (~0.5 g·kg-1) > breakfast (~0.3 g·kg-1). We conclude elite youth soccer players do not meet current CHO guidelines. Although daily protein targets are achieved, we report a skewed daily distribution in all ages such that dinner > lunch > breakfast. Our data suggest that dietary advice for elite youth players should focus on both total daily macronutrient intake and optimal daily distribution patterns.
Liam Anderson, Robert J. Naughton, Graeme L. Close, Rocco Di Michele, Ryland Morgans, Barry Drust, and James P. Morton
The daily distribution of macronutrient intake can modulate aspects of training adaptations, performance and recovery. We therefore assessed the daily distribution of macronutrient intake (as assessed using food diaries supported by the remote food photographic method and 24-hr recalls) of professional soccer players (n = 6) of the English Premier League during a 7-day period consisting of two match days and five training days. On match days, average carbohydrate (CHO) content of the prematch (<1.5 g·kg-1 body mass) and postmatch (1 g·kg-1 body mass) meals (in recovery from an evening kick-off) were similar (p > .05) though such intakes were lower than contemporary guidelines considered optimal for prematch CHO intake and postmatch recovery. On training days, we observed a skewed and hierarchical approach (p < .05 for all comparisons) to protein feeding such that dinner (0.8 g·kg-1)>lunch (0.6 g·kg-1)>breakfast (0.3 g·kg-1)>evening snacks (0.1 g·kg-1). We conclude players may benefit from consuming greater amounts of CHO in both the prematch and postmatch meals so as to increase CHO availability and maximize rates of muscle glycogen resynthesis, respectively. Furthermore, attention should also be given to ensuring even daily distribution of protein intake so as to potentially promote components of training adaptation.
Liam Anderson, Patrick Orme, Robert J. Naughton, Graeme L. Close, Jordan Milsom, David Rydings, Andy O’Boyle, Rocco Di Michele, Julien Louis, Catherine Hambly, John Roger Speakman, Ryland Morgans, Barry Drust, and James P. Morton
In an attempt to better identify and inform the energy requirements of elite soccer players, we quantified the energy expenditure (EE) of players from the English Premier League (n = 6) via the doubly labeled water method (DLW) over a 7-day in-season period. Energy intake (EI) was also assessed using food diaries, supported by the remote food photographic method and 24 hr recalls. The 7-day period consisted of 5 training days (TD) and 2 match days (MD). Although mean daily EI (3186 ± 367 kcals) was not different from (p > .05) daily EE (3566 ± 585 kcals), EI was greater (p < .05) on MD (3789 ± 532 kcal; 61.1 ± 11.4 kcal.kg-1 LBM) compared with TD (2956 ± 374 kcal; 45.2 ± 9.3 kcal.kg-1 LBM, respectively). Differences in EI were reflective of greater (p < .05) daily CHO intake on MD (6.4 ± 2.2 g.kg-1) compared with TD (4.2 ± 1.4 g.kg-1). Exogenous CHO intake was also different (p < .01) during training sessions (3.1 ± 4.4 g.h-1) versus matches (32.3 ± 21.9 g.h-1). In contrast, daily protein (205 ± 30 g.kg-1, p = .29) and fat intake (101 ± 20 g, p = .16) did not display any evidence of daily periodization as opposed to g.kg-1, Although players readily achieve current guidelines for daily protein and fat intake, data suggest that CHO intake on the day before and in recovery from match play was not in accordance with guidelines to promote muscle glycogen storage.