# 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

PMID: 40229731
Journal: BMC cancer
Published: 2025 Apr 14
Authors: Deppe I, Beller R, Kiehl F, Lazzari N, Bennstein SB, Reinhardt D, Dirksen U, Götte M

## 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.

## Population

- Adolescent and young adult cancer patients undergoing treatment and age-matched healthy controls
- Sample size: 40
- Age: Patient group 25 +/- 7 years; healthy group 27 +/- 5 years
- Fitness level: Clinical AYA cancer patients and healthy controls; baseline training status not clearly reported
- Health status: Patients were undergoing cancer treatment; controls were healthy

## Methodology

- Monocentric interventional controlled acute exercise trial
- Single 20-minute HIIT session with 1-hour recovery blood sampling
- Tertiary university hospital exercise and blood-sampling setting
- Controlled study design.

## Protocol

- 20-minute cycling HIIT.
- Modality: Bicycle ergometer.
- Work intervals: 30 seconds.
- Recovery: 60 seconds.
- Sets or repetitions: 6 intervals.
- Intensity: RPE 15-17; wattage aimed at about 1-1.5x body weight in kg when tolerated.
- Session duration: 20 minutes.
- Frequency: Single session.
- Program length: Single session.
- Progression: None.
- Healthy control same HIIT.
- Modality: Bicycle ergometer.
- Work intervals: 30 seconds.
- Recovery: 60 seconds.
- Sets or repetitions: 6 intervals.
- Intensity: RPE 15-17; wattage aimed at about 1-1.5x body weight in kg when tolerated.
- Session duration: 20 minutes.
- Frequency: Single session.
- Program length: Single session.
- Progression: None.

## Outcomes

### NK cells
Status: improved
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
Status: improved
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
Status: no clear 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.

## Practical 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 And Adherence

- 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%.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/40229731/) (pubmed)
- [DOI](https://doi.org/10.1186/s12885-025-14058-3) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11998356/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.