# A Bout of High-Intensity Interval Training (HIIT) in Children and Adolescents during Acute Cancer Treatment-A Pilot Feasibility Study PMID: 35326619 Journal: Cancers Published: 2022-03-12 Authors: Kesting S, Weeber P, Schönfelder M, Pfluger A, Wackerhage H, von Luettichau I ## 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. ## Population - Eleven analyzed children, adolescents, and young adults with pediatric malignancies during early acute cancer treatment; diagnoses included leukemia, lymphoma, rhabdomyosarcoma, nephroblastoma, and synovial sarcoma. - Sample size: 11 - Age: 13.9 +/- 3.6 years at intervention, median 15, range 7-18. - Sex: 64% male, 36% female. - Fitness level: Selected physically capable subgroup; pre-diagnosis activity averaged 4 +/- 3 active days per week and 4 +/- 3 moderate-to-vigorous days per week. - Health status: Pediatric cancer patients during acute treatment; all had received chemotherapy before examination. ## Methodology - Cross-sectional monocentric pilot feasibility study of a single supervised HIIT bout. - Single acute HIIT session, conducted as early as possible after diagnosis and within the first three cycles of chemotherapy; recruitment occurred from March 2018 to April 2021. - Department of Pediatrics and Children's Cancer Research Center, Technical University of Munich; outpatient clinic room with medical supervision. ## Protocol - Single supervised pediatric oncology HIIT cycling bout. - Modality: 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. - Sets or repetitions: 10 intervals. - Intensity: >90% estimated HRmax target; Borg 14-16 target; workload increased individually by 10-50 W. - Session duration: About 12.5 minutes of intervals/recoveries plus 2-minute warm-up and 1 minute pre-interval low-intensity cycling. - Frequency: Single session. - Program length: Acute bout only. - Progression: Individual workload increments based on Borg scale feedback. ## Outcomes ### Recruitment feasibility Status: worse/safety concern 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 Status: improved 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 Status: improved 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 Status: improved 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 Status: improved 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 Status: no clear change Adrenaline concentration did not significantly change from rest to post-exercise despite high variability. No significant change; exact p value not reported in extracted text. ## Practical 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 And Adherence - 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. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/35326619/) (pubmed) - [DOI](https://doi.org/10.3390/cancers14061468) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8945900/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.