PMID 35996161

Research
All papers

Effects of different training intensities on blood lymphocytes, monocytes and neutrophils in young male athletes

Rhibi F, Abderrahman AB, Prioux J, Clark CCT, Bideau B, Besbes S, Hackney AC, Granacher U, Zouhal H

Question

Do 8 weeks of running HIIT at 100% versus 110% maximal aerobic velocity produce different aerobic, muscle-damage, inflammatory, and hematological adaptations in young male physical education students?

Summary

In young active men, 8 weeks of supervised 30 s running intervals improved maximal aerobic velocity. Training at 110% of maximal aerobic velocity improved more than 100%, but the study was small and athlete-specific.

Methodology

  • Healthy male physical education students assigned to control, 100% MAV HIIT, or 110% MAV HIIT.
  • 29 participants.
  • running.
  • Work intervals: 30 s.
  • Recovery: 30 s active recovery at 50% MAV; 5 min passive recovery between 2 series.
  • Intensity: 110% maximal aerobic velocity for work intervals.
  • about 44-52 min including 20 min warm-up, inter-series rest, recoveries, and cool-down.
  • 3 sessions/week with at least 48 h between sessions.
  • 8 weeks; 24 sessions.
  • parallel-group randomized controlled training study
  • Maximal aerobic velocity, Muscle damage and inflammation markers, and White blood cell profile were tracked.

Outcomes

MAV

Both HIIT groups improved, with larger improvement after 110% MAV than 100% MAV.

EG100 +5.8%; EG110 +8.9%; group x time p<0.001, eta2=0.61; post-HIIT EG110 vs EG100 p=0.01, eta2=0.05

Improved

Muscle markers

Liver and muscle-damage markers generally decreased; CK decreased only in the 110% group.

ALAT and ASAT lower in both groups; EG110 lower than EG100 post-HIIT for ALAT p=0.04 and ASAT p=0.02; CK decreased only in EG110 p=0.01

Improved

Immune cells

White blood cells and neutrophils decreased in both HIIT groups; lymphocytes decreased only in the higher-intensity group.

WBC and NE decreased in both exercise groups; LY decreased only in EG110; monocytes unchanged

Mixed

Insights

  • Thirty-second running intervals can be progressed by adding repetitions across weeks while keeping work and recovery fixed.
  • The stronger 110% MAV dose improved aerobic speed more in this active male sample, but it requires individual fitness testing and supervision.
  • Blood marker changes were interpreted as adaptation and possible transient immune suppression, so recovery spacing matters.

Limitations

  • Small sample of young active men.
  • No soreness or muscle strength outcomes.
  • Protocol depends on measured maximal aerobic velocity and track pacing.

Safety

  • No testing or training injuries occurred; blood-cell changes included reduced WBC/neutrophils and lymphocytes in the higher-intensity group.