Dan Fransson (PhD), Helena Andersson (Med.Dr.Sci) and Hannah Hüttemann (Msc).2023
Background
Women’s football match-play has developed rapidly in the last two decades and the number of players has increased to 13.4 million active players worldwide. On the elite level the physical match- demands have expanded from 8,5 km to 10-11 km in total distance and of those 10-11 km around 2.0 km are covered in high speed 1. On top of the physical demands of elite female matches, around 30 bouts are made in sprinting speed (> 25 km·h1) 2. Furthermore, explosive accelerations (> 3 m/s2) and decelerations (<- 3 m/s2) are performed around every 5 minutes during an international tournament in top-class female players 3. Finally, it has been shown that well-developed explosive capacities can minimize the risk of injury, in male football 4.
Thus it seems that explosive actions are occurring in elite female football matches and preparing players for the physical match demands is important to reduce the risk of injuries and potentially increase physical performance.
Women’s football match-play has developed rapidly in the last two decades and the number of players has increased to 13.4 million active players worldwide. On the elite level the physical match- demands have expanded from 8,5 km to 10-11 km in total distance and of those 10-11 km around 2.0 km are covered in high speed 1. On top of the physical demands of elite female matches, around 30 bouts are made in sprinting speed (> 25 km·h1) 2. Furthermore, explosive accelerations (> 3 m/s2) and decelerations (<- 3 m/s2) are performed around every 5 minutes during an international tournament in top-class female players 3. Finally, it has been shown that well-developed explosive capacities can minimize the risk of injury, in male football 4.
Thus it seems that explosive actions are occurring in elite female football matches and preparing players for the physical match demands is important to reduce the risk of injuries and potentially increase physical performance.
In 2021, a project with the long-term aim to develop female elite football players' explosive capacities in Sweden started. The initiative makers are the Swedish elite football organization (EFD), Photon Sport and are partly financed by Folksam, Sparbanksstiftelsen Skåne och Infrastructure Logistics.
Methods
Data collection was performed on 277 female players in the first league in Sweden with a 3D camera technology-based system from Photon Sports. The system digitizes the movement of a player’s approximate Center Of Mass with high speed and accuracy by tracking a marker (vest or waist belt) in three dimensions.
Data collection was performed on 277 female players in the first league in Sweden with a 3D camera technology-based system from Photon Sports. The system digitizes the movement of a player’s approximate Center Of Mass with high speed and accuracy by tracking a marker (vest or waist belt) in three dimensions.
The system has been validated in collaboration with Bosön (the Swedish National Sports Confederation’s development center) and Umeå University.
Sprint validation has been performed using SmartSpeed by Vald, WittyGate by MicroGate, wirebased systems such as 1080 Sprint and Dynaspeed. Good agreements were found between these systems and Photon Sports.
For jump validation the Oqus 300+ (Qualisys AB®, Gothenburg, Sweden) and Qualisys Track Manager software was used with high correlation between Qualisys and Photon Sports.
Validation reports are available (“Validation Report - Countermovement Jump” and “Validation Report - 30 metres sprint”) on demand.
The chosen tests were 5 m sprint, 30 m sprint, and countermovement jump (CMJ). The tests were prioritized based on proven game demands and a recent article made on English female players 5.
All tests were performed after a warm-up at least 72 hours after the last match. The test period was the season from January-November in 2022 and includes data from the pre-season and competitive season.
Results
Table 1. The results of the countermovement jumps of a total of 821 jumps of 124 players (mean ~ 7 jumps per player).
Table 1. The results of the countermovement jumps of a total of 821 jumps of 124 players (mean ~ 7 jumps per player).
| Mean | SD | |
|---|---|---|
| Jump Height | 39.33 cm | ± 5.00 cm |
| Max Power | 47.18 W | ± 5.82 W |
| Average Power | 21.56 W | ± 3.36 W |
Table 3. The results from standing sprints (5-30 m) of a total of 172 sprints by 66 players (mean ~ 2,5 sprints per player).
| Mean | SD | |
|---|---|---|
| Max Speed | 7.92 m/s | ± 1.29 m/s |
| Split time 2.5 m | 0.90 s | ± 0.14 s |
| Split time 5 m | 1.37 s | ± 0.17 s |
| Split time 10 m | 2.22 s | ± 0.20 s |
| Split time 20 m | 3.59 s | ± 0.34 s |
| Split time 30 m | 5.05 s | ± 0.56 s |
Figure 1. Variations of countermovement jump height over a season in 232 tests of 20 players.
Correlations
The correlation between jump height in CMJ and the maximum speed was 0.90 which can be defined as an extremely strong correlation.
Discussion
The mean jump height for the Swedish elite players was 39,33 cm, similar to English elite female players 5. The power conducted during CMJ has been related to 10-meter acceleration performance in elite athletes in previous studies 6. In the present investigation, there was no significant correlation between CMJ maximum power and 30 m sprint split times (2.5, 5, 10, 15, 20, and 30 m) (r = 0.02-0.18) nor CMJ maximum jump height and 30 m sprint split times (r = 0.03-0.22). However, an extremely large correlation (r = 0.9) was found between CMJ height and maximum speed during the 30 m sprint test. These results indicate that CMJ height performance may be an important marker for top-speed performance in football-specific sprints, in elite women’s football.
Explosive performance based on CMJ markers has been seen to be associated with both neuromuscular and metabolic fatigue in a trained population 7. In the present pilot study, the variation in CMJ performance was on average 0.2 ± 5.4 % over a season. This is a very small fluctuation, however, the individual results fluctuated from -14.4 % to 18.9 %. The variation may be a change in explosive capacity but it may also indicate neuromuscular or metabolic fatigue. As all CMJ tests were performed on matchday + 3 the variation could be an indicator of insufficient post-match recovery as previous studies have found that neuromuscular recovery may be decreased for more than 72 hours after a female elite football match 8. Monitoring CMJ as a marker for neuromuscular performance and fatigue in elite football will give valuable information for coaches to plan training and recovery strategies on an individual level.
Future directions
In general, the number of studies investigating women’s football has increased the last decade, but more knowledge is warranted 9. Moreover, the physiology of the male and female population in training studies and their training response has been shown to differ 10. Therefore, a deeper understanding of women’s physical and physiological response to football-specific training methodology is necessary to get a deeper understanding and for practitioners to plan and conduct training, specific for female players.
In the present project, we aim to investigate if neuromuscular performance can distinguish between player positions and if there may be a difference between elite players and top-class players in the Swedish first league. Moreover, we aim at designing a training study on how to improve football-specific neuromuscular capacity in elite female players as we know from previous male studies that it is important from a performance perspective 3 and to lower the risk of injuries 4.
References
- Datson N, Drust B, Weston M, Jarman IH, Lisboa PJ, Gregson W. Match Physical Performance of Elite Female Soccer Players During International Competition. J Strength Cond Res 2017; 31:2379–87.
- Mohr M, Krustrup P, Bangsbo J. Match performance of high-standard soccer players with special reference to the development of fatigue. J Sports Sci 2003; 21:519–28.
- Yousefian F, Hüttemann H, Börjesson M, Ekblom P, Mohr M and Fransson D., Physical workload and fatigue pattern characterization in a top-class women's football national team: a case study of the 2019 FIFA Women's World Cup. Journal of Sports Medicine And Physical Fitness, 2021; 61 (8): 1081-90.
- Malone S, Owen A, Mendes B, Hughes B, Collins K, Gabbett TJ. High-speed running and sprinting as an injury risk factor in soccer: Can well-developed physical qualities reduce the risk? J Sports Sci Med. 2018;21(3):257-62.
- Datson N, Drust B, Weston M, Jarman IH, Lisboa PJ, Gregson W. Match Physical Performance of Elite Female Soccer Players During International Competition. J Strength Cond Res 2017; 31:2379–87.
- Maulder PS, Bradshaw EJ, and Keogh J. Jump kinetic determinants of sprint acceleration performance from starting blocks in male sprinters.J Sports Sci Med 2006 ; 5 (2): 359-6.
- Wu PPY, Sterkenburg N, Everett K, Chapman DW, White N, and Mengersen K. Predicting fatigue using countermovement jump force-time signatures: PCA can distinguish neuromuscular versus metabolic fatigue. PloS one 2019; 14 (7): e0219295-e0219295, DOI: 10.1371/journal.pone.0219295
- Andersson H, Raastad TNilsson, J, Paulsen G, Garthe I and Kadi F. Neuromuscular fatigue and recovery in elite female soccer: effects of active recovery. Med Sci Sports Exerc 2008; 40 (2): 372-80. DOI: 10.1249/mss.0b013e31815b8497
- Okholm Kryger K, Wang A, Mehta, R, Impellizzeri FM, Massey A, and McCall A. Research on women's football: a scoping review. Science and medicine in football 2022; 6 (5): 549-558, DOI: 10.1080/24733938.2020.1868560
- Ansdell P, Thomas K, Hicks KM, Hunter SK, Howatson G, and Goodall S. Physiological sex differences affect the integrative response to exercise: acute and chronic implications Experimental physiology 2020; 105 (12): 2007-2021. DOI: 10.1113/EP088548
This study was made possible in collaboration with:
