A Bout of High-Intensity Interval Training (HIIT) in Children and Adolescents during Acute Cancer Treatment-A Pilot Feasibility Study
Question
Can a single bout of 10 x 15-second high-intensity interval cycling with active recovery be safely and feasibly performed by pediatric cancer patients during the first three chemotherapy courses, and does it elicit physiological responses such as increased heart rate, lactate, and adrenaline?
Summary
This monocentric pilot feasibility study tested whether a single supervised HIIT bout could be performed safely by selected children and adolescents during early acute cancer treatment. Of 212 newly diagnosed screened patients, only 14 were included and 11 completed the intervention, showing that the protocol was applicable only to a very small and relatively fit subgroup. The completed bout produced clear exertional responses, including heart rate near the target and increased blood lactate, with no serious adverse events.
Methodology
- Eleven analyzed children, adolescents, and young adults with pediatric malignancies during early acute cancer treatment; diagnoses included leukemia, lymphoma, rhabdomyosarcoma, nephroblastoma, and synovial sarcoma.
- 11 participants.
- Seated bicycle ergometer cycling.
- Work intervals: 15 seconds.
- Recovery: 1 minute active cycling recovery at 25 W on adult ergometer or 0 W on children's ergometer.
- Intensity: >90% estimated HRmax target; Borg 14-16 target; workload increased individually by 10-50 W.
- About 12.5 minutes of intervals/recoveries plus 2-minute warm-up and 1 minute pre-interval low-intensity cycling.
- Single session.
- Acute bout only.
- Cross-sectional monocentric pilot feasibility study of a single supervised HIIT bout.
- Feasibility, Safety, Heart rate, and Blood lactate were tracked.
Outcomes
Recruitment feasibility
Only 14 of 212 screened patients were included and 11 completed the intervention, so the protocol applied only to a very small selected subgroup.
11/212 completed, about 5%; 195 did not meet strict inclusion criteria.
Acceptance/completion
Among participants who started the intervention, the predefined acceptance criterion was met.
Table reports 83% (10/12) finished the intervention; one additional participant stopped after the eighth interval and was included in analysis.
Safety
No serious adverse events and no adverse events with consequences occurred.
One nausea-related discontinuation after first interval; one slight nose bleed after ninth interval; one leg-fatigue interruption after eighth interval.
Heart rate
Heart rate increased from rest to post-exercise and reached the intended high-intensity range in participants with available HR data.
78 +/- 17 bpm at rest to 178 +/- 12 bpm post-exercise, corresponding to 90 +/- 6% estimated HRmax; n = 7/11; p < 0.0001 reported in figure caption.
Blood lactate
Blood lactate increased after the HIIT bout, supporting achieved high exertion.
1.09 +/- 0.50 mmol/L at rest to 5.05 +/- 1.88 mmol/L post-exercise; p < 0.0001.
Plasma adrenaline
Adrenaline concentration did not significantly change from rest to post-exercise despite high variability.
No significant change; exact p value not reported in the paper.
Insights
- A 10 x 15-second cycling HIIT bout can achieve high intensity in carefully selected, medically supervised pediatric cancer patients.
- This protocol should not be treated as broadly applicable pediatric cancer exercise guidance because screening excluded most patients.
- For medically vulnerable populations, feasibility evidence is inseparable from screening, supervision, and conservative stop rules.
Limitations
- Small analyzed sample.
- No control group.
- Single acute bout rather than repeated training.
- Highly selected population with strict inclusion criteria.
- Recruitment heavily limited by clinical contraindications and COVID-19 restrictions.
- Heart-rate data available for only 7 of 11 participants.
- No long-term clinical, fitness, or cancer outcome assessment.
Safety
- No serious adverse events and no adverse events with consequences occurred.
- One participant discontinued after the first interval due to pre-existing treatment-related nausea in association with chemotherapy.
- One participant had slight nose bleeding after the ninth interval, reported as a regular pre-cancer occurrence, and finished the intervention.
- One participant interrupted after the eighth interval due to muscular tiredness of the legs and was included in final analysis.
- Safety procedures included physician clearance, medical supervision, seated cycling, central venous catheter precautions, at least two people present, and 30-minute observation.