PMID 39979557

Research
All papers

Morning sprint interval training produces greater physical performance adaptations than evening training in soccer players

Yan B, Li L

Question

Does the time of day of sprint interval training affect physical and physiological adaptations in trained soccer players?

Summary

In 30 male college soccer players, adding 7 weeks of supervised sprint interval running to regular soccer practice improved jumping, sprinting, change-of-direction, intermittent running, VO2max, and Wingate power. Morning sprint sessions at 8 AM produced larger gains than evening sessions at 5 PM on several performance outcomes.

Methodology

  • Male College Division II soccer players
  • 30 participants.
  • Field running.
  • Work intervals: 5 seconds all-out.
  • Recovery: 1:3 recovery between efforts; 3 minutes between sets.
  • Intensity: All-out.
  • About 50 minutes including warm-up and cool-down.
  • 3 sessions/week.
  • 7 weeks.
  • Randomized controlled training study
  • Physical performance, Aerobic fitness, and Safety were tracked.

Outcomes

Performance adaptations

Both SIT groups improved jump, sprint, change-of-direction, Yo-Yo IR1, VO2max, and Wingate power versus baseline and control.

Reported p<0.05 for pre-post SIT changes with small to very large effect sizes.

Improved

Morning vs evening

Morning SIT produced greater gains than evening SIT for CMVJ, 20-m sprint, Yo-Yo IR1, peak power, and average power.

Significant interactions were reported for multiple outcomes; CMVJ interaction p=0.001 in the displayed table.

Improved

Safety

No training-related injuries were reported.

Descriptive safety reporting only.

No clear change

Insights

  • For trained, sprint-ready users, very short all-out efforts can be paired with generous recovery and still drive performance gains.
  • Time of day may be worth exposing as a scheduling preference, but this study does not justify a general morning-is-best claim.
  • A 15-minute warm-up before maximal sprint intervals is a key safety and readiness detail.

Limitations

  • Small sample of male college soccer players.
  • Athlete-only, supervised field sprinting protocol limits general fitness translation.
  • No post-intervention follow-up.
  • One methods sentence appears inconsistent about intervention length, while tables and results describe 7 weeks.

Safety

  • No reported injuries related to the training intervention.
  • Participants were screened for recent lower-body injury and limiting medical/orthopedic conditions.