Abstract Objectives Running economy is a key determinant of endurance performance, and understanding the biomechanical factors that affect it is of great theoretical and applied interest. This study ...aimed to analyse how the ground-contact time and strike pattern used by competitive runners concurrently affect running economy. Design Cross-sectional. Methods Fourteen sub-elite male competitive distance runners completed a 6-min submaximal running trial at 14 km h−1 on an outdoor track using their habitual strike pattern ( n = 7 rearfoot strikers: average age, 25.3 years old (SD = 2.4); average weight, 64.7 kg (SD = 5.6); average height, 175.3 cm (SD = 5.2); n = 7 midfoot strikers: average age, 25.0 years old (SD = 2.8); average weight, 69.6 kg (SD = 4.0); average height, 180.1 cm (SD = 5.1). During the run, the oxygen uptake and ground-contact time were measured. Results Midfoot strikers showed a significantly shorter ( p = 0.015) mean contact time (0.228 s (SD = 0.009)) compared with rearfoot strikers (0.242 s (SD = 0.010)). Conversely, there was no significant difference ( p > 0.05) between the groups with respect to mean oxygen uptake (midfoot strikers: 48.4 ml min−1 kg−1 (SD = 5.3); rearfoot strikers: 49.8 ml min−1 kg−1 (SD = 6.4)). Linear modelling analysis showed that the effect of contact time on running economy was very similar in the two groups, with a 1 ms longer contact time involving an approximately 0.51 ml min−1 kg−1 lower oxygen uptake. In contrast, when controlling for contact time, midfoot striking involved an approximately 8.7 ml min−1 kg−1 lower oxygen uptake compared with rearfoot striking. Conclusions When adjusting the foot–ground contact biomechanics of a runner with the aim of maximising running economy, a trade-off between a midfoot strike and a long contact time must be pursued.
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). Methods 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. Conclusions 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.
The influence of environmental factors on key physical parameters of soccer players during competitive match-play have been widely investigated in the literature, although little is known on the ...effects of sub-zero ambient temperatures on the performance of adult elite soccer players during competitive matches. The aim of this study was to assess how the teams' match running performance indicators are related to low ambient temperature during competitive matches in the Russian Premier League. A total of 1142 matches played during the 2016/2017 to 2020/2021 seasons were examined. Linear mixed models were used to assess the relationships between changes in ambient temperature at the start of the match and changes in selected team physical performance variables, including total, running (4.0 to 5.5 m/s), high-speed running (5.5 to 7.0 m/s) and sprint (> 7.0 m/s) distances covered. The total, running and high-speed running distances showed no significant differences across temperatures up to 10°C, while these showed small to large decreases at 11 to 20°C and especially in the >20°C ranges. On the contrary, sprint distance was significantly lower at temperature of -5°C or less compared to higher temperature ranges. At sub-zero temperatures, every 1°C lower reduced team sprint distance by 19.2 m (about 1.6%). The present findings show that a low ambient temperature is negatively related to physical match performance behavior of elite soccer players, notably associated with a reduced total sprint distance.
Listening to music during strength workouts has become a very common practice. The goal of this study was to assess the effect of listening to self-selected music on strength performances. Thirty-one ...resistance-trained men (M age = 24.7yr., SD = 5.9; M height = 178.7cm, SD = 4.7; M body mass = 83.54kg, SD = 12.0) were randomly assigned to either a Music group (n = 19) or to a Control group (n = 12). Both groups took part in two separate sessions; each session consisted in a maximal strength test (1-RM) and a strength-endurance test (repetitions to failure at 60% 1-RM) using the bench press exercise. The music group listened to music in the second assessment session, while the control group performed both tests without music. Listening to music induced a significant increase of strength endurance performance and no effects on maximal strength. These findings have implications for the use of music during strength workouts.
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.
The authors aimed to quantify (a) the periodization of physical loading and daily carbohydrate (CHO) intake across an in-season weekly microcycle of Australian Football and (b) the quantity and ...source of CHO consumed during game play and training. Physical loading (via global positioning system technology) and daily CHO intake (via a combination of 24-hr recall, food diaries, and remote food photographic method) were assessed in 42 professional male players during two weekly microcycles comprising a home and away fixture. The players also reported the source and quantity of CHO consumed during all games (n = 22 games) and on the training session completed 4 days before each game (n = 22 sessions). The total distance was greater (p < .05) on game day (GD; 13 km) versus all training days. The total distance differed between training days, where GD-2 (8 km) was higher than GD-1, GD-3, and GD-4 (3.5, 0, and 7 km, respectively). The daily CHO intake was also different between training days, with reported intakes of 1.8, 1.4, 2.5, and 4.5 g/kg body mass on GD-4, GD-3, GD-2, and GD-1, respectively. The CHO intake was greater (p < .05) during games (59 ± 19 g) compared with training (1 ± 1 g), where in the former, 75% of the CHO consumed was from fluids as opposed to gels. Although the data suggest that Australian Football players practice elements of CHO periodization, the low absolute CHO intakes likely represent considerable underreporting in this population. Even when accounting for potential underreporting, the data also suggest Australian Football players underconsume CHO in relation to the physical demands of training and competition.
Running with the ball is a soccer-specific activity frequently used by players during match play and training drills. Nevertheless, the energy cost (EC) of on-grass running with the ball has not yet ...been determined. The purpose of this study was therefore to assess the EC of constant-speed running with the ball, and to compare it with the EC of normal running. Eight amateur soccer players performed two 6- min runs at 10 km/h on artificial turf, respectively with and without the ball. EC was measured with indirect calorimetry and, furthermore, estimated with a method based on players' accelerations measured with a GPS receiver. The EC measured with indirect calorimetry was higher in running with the ball (4.60±0.42 J/kg/m) than in normal running (4.19±0.33 J/kg/m), with a very likely moderate difference between conditions. Instead, a likely small difference was observed between conditions for EC estimated from GPS data (4.87±0.07 vs. 4.83±0.08 J/kg/m). This study sheds light on the energy expenditure of playing soccer, providing relevant data about the EC of a typical soccer-specific activity. These findings may be a reference for coaches to precisely determine the training load in drills with the ball, such as soccer-specific circuits or small-sided games.
Bartolomei, S, Rovai, C, Lanzoni, IM, and di Michele, R. Relationships between muscle architecture, deadlift performance, and maximal isometric force produced at the midthigh and midshin pull in ...resistance-trained individuals. J Strength Cond Res 36(2): 299-303, 2022-The aim of this study was to investigate the relationships between muscle architecture, lower-body power, and maximal isometric force produced at midthigh pull (MTP), and at midshin pull (MSP). Twenty experienced resistance-trained men (age = 25.5 ± 3.2 years; body mass = 86.9 ± 12.4 kg; body height = 178.0 ± 5.3 cm) were tested for deadlift 1 repetition maximum (1RM), countermovement jump (CMJ), peak force (PF), and rate of force development (pRFD20) produced at isometric MTP and isometric MSP. Subjects were also assessed for architecture of vastus lateralis (VL). Physiological muscle thickness, pennation angle, and fascicle length (FL) were measured. Pearson's correlation coefficients were calculated to assess the relationships between variables. In addition, differences between MTP and MSP were assessed using paired-sample t-tests. A significant (p < 0.05) difference was detected on the correlation between deadlift 1RM and MSP (r = 0.78; p < 0.001) compared with MTP (r = 0.55; p = 0.012). Moderate correlations were observed between MSP PF and VLFL (r = 0.55; p = 0.011). Midshin pull pRFD20 was the only parameter significantly correlated with CMJ (r = 0.50; p = 0.048). Significantly higher PF and pRFD20 were recorded in MTP compared with MSP (p = 0.007 and p = 0.003, respectively). The present results show that force produced from the floor position may be more important than force produced from a position that mimics the second pull of the clean for deadlift and vertical jump performances. Coaches and scientific investigators should consider using MSP to assess isometric PF using a test correlated with both muscle architecture and dynamic performances.
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