Exercise-based strategies to prevent muscle injury in male elite footballers: an expert-led Delphi survey of 21 practitioners belonging to 18 teams from the Big-5 European leagues

Key points

1. 01Sprinting (>25.2 km/h) and HSR (>19.8 km/h) were rated 'very effective' (+++) by 72% (13/18) consensus; eccentric exercise was rated 'effective' (++) by 100% of respondents.
2. 02Eight other exercise modes - concentric, isometric, horizontal and vertical plyometrics, coordination, core stability, dynamic and static flexibility - reached consensus as 'somewhat effective' (+).
3. 03No consensus was reached for multi-joint exercises (e.g. squats, Olympic lifts), single-leg strength and stability, agility, kicking, or resisted sprints.
4. 04In a 6-day between-match cycle, the preferred day for sprinting and HSR is matchday minus 3 (M-3); for eccentric exercise it is matchday plus 3 (M+3); during 3-day or fewer recovery periods, no targeted sprinting or HSR was deemed necessary for starters.
5. 05Expert panel agreed that exercise-based prevention must be combined with non-exercise strategies: load management of the training week (100%, +++), consideration of prior injury (94%, ++), team communication (83%, ++), and recovery strategies (78%, ++).

How it was conducted

Design

Four-round Delphi consensus survey with anonymous sequential questionnaires

Participants

21 sports practitioners (mean 12 +/- 5.3 years elite football experience) representing 18 teams from England, France, Germany, Italy, and Spain (Big-5 European leagues)

Consensus threshold

Agreement defined as 70% of respondents (13/18) selecting the same option on closed questions or recurring themes on open questions

Rounds

4 rounds; 100% response rate in each; conducted December 2017 to March 2018

Exercise modes assessed

13 predefined exercise types rated on a Likert scale (not effective / somewhat effective / effective / very effective) plus open questions for additional modes

What they found

• Sprinting and HSR rated 'very effective' (+++): 72% consensus (13/18 respondents).
• Eccentric exercise rated 'effective' (++): 100% consensus (18/18 respondents).
• Concentric, isometric, horizontal and vertical plyometrics, coordination/activation, dynamic flexibility, and core stability each reached 'somewhat effective' (+) consensus, with individual agreement rates of 78-100%.
• Static flexibility reached 'somewhat effective' (+) consensus in Round 2.
• No consensus after two rounds for multi-joint exercises, single-leg strength and stability, agility, kicking, or resisted sprints (rated between 'not effective' and 'very effective').
• For sprinting/HSR in a 6-day recovery week: 94% (16/18) agreed M-3 is the preferred day; 89% (16/18) agreed M-3 in a 5-day cycle.
• Target during the training week: 100% of the individual player's worst-case match scenario for sprinting and HSR (consensus in Round 3, 17/18 responses included).
• For eccentric exercise in a 6-day recovery week: M+3 preferred, 78% (14/18) consensus; in a 5-day cycle, M+3 also agreed, 83% (15/18).
• Low-intensity eccentric exercise permitted in congested schedules (3-day or fewer recovery): 71% (12/18) consensus, contingent on players being sufficiently accustomed.
• Eccentric exercise can be performed before or after training session: consensus reached in Round 4 (67% - 12/18 - agreed it is possible around the same session as sprinting/HSR, but highly contextual).
• No consensus on optimal number of eccentric exercises per session, nor on sets and repetitions for either low- or high-intensity eccentric exercise.
• Overall load management of the training week agreed as 'very effective' (+++): 100% (18/18).
• Prior injury history agreed as 'effective' (++): 94% (17/18).
• Team communication agreed as 'effective' (++): 83% (15/18).
• Recovery strategies agreed as 'effective' (++): 78% (14/18).

Limitations

• Findings represent level 5 evidence (expert opinion only) and are not substantiated by high-quality experimental studies in elite male footballers.
• Only 18 teams and 21 practitioners included; views may not represent all elite football cultures and the sample over-represents sport science professionals versus physiotherapists or physicians.
• The Delphi process took from December 2017 to publication (over 1.5 years), and expert views may have evolved with new research published in the interim.
• English fluency was an inclusion criterion, potentially excluding non-English-speaking practitioners and limiting cultural representativeness.

Why it matters

For patients

Elite footballers and their coaches can use this consensus to prioritise sprint and high-speed running exposure plus eccentric strength work in weekly training, scheduled around match density, to reduce muscle injury risk.

For clinicians

Sports medicine and performance staff should integrate sprinting, HSR, and eccentric exercise into the training week using match-proximity scheduling (e.g. M-3 for sprinting, M+3 for eccentric), individualise loads to each player's maximum speed, and combine these with load management and recovery strategies.

For readers

This Delphi survey captures what top European football practitioners actually do, not what randomised trials prove; high-quality interventional studies are still urgently needed to validate or refute these expert-based recommendations.