The impact of a single HIIT intervention on the mobilization of NK cells and ILCs in adolescents and young adults (AYA) undergoing cancer treatment: an interventional controlled trial
Question
Does a single high-intensity interval cycling session mobilize NK cells, ILCs, and their subpopulations in adolescent and young adult cancer patients similarly to healthy controls?
Summary
In 20 adolescents and young adults undergoing cancer treatment and 20 matched healthy controls, one supervised 20-minute bicycle HIIT session acutely mobilized several natural killer cell and innate lymphoid cell populations. The percent changes were not significantly different between patients and healthy controls, but this was an acute immune-cell study rather than evidence that regular HIIT improves cancer outcomes.
Methodology
- Adolescent and young adult cancer patients undergoing treatment and age-matched healthy controls
- 40 participants.
- Bicycle ergometer.
- Work intervals: 30 seconds.
- Recovery: 60 seconds.
- Intensity: RPE 15-17; wattage aimed at about 1-1.5x body weight in kg when tolerated.
- 20 minutes.
- Single session.
- Single session.
- Monocentric interventional controlled acute exercise trial
- NK and ILC mobilization, and Heart-rate association were tracked.
Outcomes
NK cells
Total NK cells and CD56dim NK cells increased immediately after HIIT in both patient and healthy groups, then decreased during recovery.
T0 to T1 total NK: PG p=0.023, HG p=0.004; CD56dim: PG p=0.035, HG p=0.004. T1 to T2 both p<0.001 for total and CD56dim NK cells.
ILCs
Total ILCs, ILC1-like, ILC2, and ILCPs increased after HIIT in both groups; ILC1-like stayed elevated during recovery.
Total ILCs T0 to T1 p<0.001 in both groups; ILC1-like PG p=0.001, HG p=0.004; ILC2 PG p=0.006, HG p=0.003; ILCPs PG p=0.009, HG p=0.002.
Between-group change
Patient and healthy groups did not differ significantly in percentage cell-count changes from T0 to T1 or T1 to T2.
No significant inter-group comparisons reported for percentage changes.
Insights
- Acute supervised cycling HIIT can be studied in AYA cancer treatment settings with clinical oversight.
- Immune-cell mobilization should be described as a mechanistic response, not a direct health outcome.
Limitations
- Small pilot sample
- Single acute session
- Clinical oncology population
- Adverse events were not explicitly reported
Safety
- Article did not report adverse events for the acute session.
- Patients were physician-screened for HIIT contraindications, including fracture risk from tumor/metastases, chemotherapeutic cardiotoxicity, and surgery-related movement or loading restrictions.
- Pretesting required no chemotherapy in the prior 48 hours, hemoglobin >=8 mg/dL, and platelets >=20,000/uL; exercise was supervised with HR, RPE, rpm, and oxygen saturation monitoring with SpO2 kept >=90%.