Authors: Antonio Alonso-Callejo et al.
Journal: International Journal of Sports Physiology and Performance (IJSPP), 2025

Integration of in situ sprint profiling into applied performance monitoring without the need for isolated testing.

AI written summary:

Aim

The study evaluated how to obtain reliable acceleration–speed (A–S) profiles in elite male and female footballers over three competitive seasons. It explored how the number and type of training microcycles (competitive vs noncompetitive) influence the reliability of theoretical maximal acceleration (A₀) and maximal speed (S₀) derived from GPS data.

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Methods

• Data were collected from female (Champions League level) and male (U21) teams of the same club across 2022–2025.
• GPS (18 Hz) measured accelerations and speeds in all training sessions and official matches.
• A–S profiles were calculated using linear regression between acceleration and speed data.
• Microcycles were grouped into windows of 1–5 consecutive weeks to test reliability.
• Sessions including match day (MD) or the day after (MD + 1) were classified as competitive (COMP); others as noncompetitive (N-COMP).
• Reliability was analyzed using coefficients of variation (CV), signal-to-noise ratio (SNR), and Fourier-based signal energy.

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Results

• A₀ and S₀ increased with longer microcycles but stabilized beyond five days.
• The most reliable results were obtained from two consecutive microcycles (each ≥5 sessions, including MD or MD + 1).
• Competitive profiles produced higher signal quality, less noise, and greater stability than noncompetitive ones.
• Male players showed lower variability and higher SNRs than female players, indicating more consistent sprint data.
• Profiles based on short or noncompetitive microcycles were less reliable and underestimated A₀ and S₀.

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Practical Applications

• Reliable A–S profiling can be achieved without isolated sprint tests, by using two competitive microcycles.
• This approach allows coaches to:
  • Track sprint and acceleration capacities continuously,
  • Detect performance changes or imbalances,
  • Optimize individualized training and rehabilitation programs.

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Conclusions

• The reliability of acceleration–speed profiling depends on the structure and content of the training microcycles.
• Two competitive microcycles (with ≥5 sessions, one being MD or MD + 1) provide sufficient data for accurate monitoring.
• This “testing without testing” method offers a practical, noninvasive, and ecologically valid approach to tracking sprint performance in elite football.