PMID 41750333

Research
All papers

Chemokine Receptor Profile of Circulating Leukocyte Subsets in Response to Acute High-Intensity Interval Training

Leuchte K, Fresnillo Saló S, Rahbech A, Byrdal M, Vinther A, Holmen Olofsson G

Question

How does one bout of HIIT affect chemokine receptor expression and mobilization of leukocyte subsets in healthy adults?

Summary

Sixteen healthy adults completed one supervised mixed warm-up plus cycling HIIT session. Blood tests showed rapid immune-cell redistribution immediately after exercise and partial reversal one hour later, but the study measured immune phenotypes rather than fitness or health outcomes.

Methodology

  • Healthy adults from the INHALE cohort.
  • 16 participants.
  • Mixed warm-up plus cycling.
  • Work intervals: 20 s all-out at about 100% CPET maximal power.
  • Recovery: 20 s easy pedaling at about 50%; 3 min steady-state between 3 min blocks.
  • Intensity: All-out/prescribed power with HR monitoring.
  • About 32 min plus transitions.
  • Single session.
  • Acute study.
  • Acute interventional laboratory study
  • Leukocyte mobilization, and Chemokine receptor expression were tracked.

Outcomes

NK cells

NK cells strongly mobilized immediately and fell below baseline after 60 min.

6.6-fold increase at Ex02 and 2.7-fold below baseline at Ex60; p<0.0001.

Mixed

CD4 T cells

CD4+ T cells increased immediately and returned toward baseline by 60 min.

1.5-fold increase and 1.8-fold decrease at Ex60; p<0.0001.

Mixed

Gamma-delta T cells

Gamma-delta T cells mobilized immediately and returned to baseline after recovery.

4.2-fold increase at Ex02; p<0.01.

Mixed

Insights

  • Short all-out intervals can produce rapid systemic physiological effects in healthy adults.
  • Immune-marker findings are mechanistic and should not be converted into consumer claims about immunity without functional outcome evidence.

Limitations

  • Small sample.
  • Single acute bout only.
  • Healthy participants only.
  • Functional immune consequences were not measured.
  • Limited chemokine receptor panel.

Safety

  • No adverse events were reported.
  • Participants were screened as healthy, excluded for exercise-limiting conditions and relevant medications, and exercised under experienced physiotherapist supervision.
  • The study used all-out intervals, so safety should not be generalized to unscreened or clinical users.