# Efficacy and Safety of High-Intensity Interval Training in a Patient With Acute Lymphocytic Leukemia Receiving Consolidation Chemotherapy: A Case Report

## TL;DR

A patient with leukemia undergoing chemotherapy improved exercise tolerance safely using high-intensity interval training.

## Contribution

Demonstrates the safety and efficacy of HIIT as a rehabilitation strategy during chemotherapy for leukemia patients.

## Key findings

- HIIT improved exercise tolerance in a leukemia patient undergoing chemotherapy.
- No adverse events occurred during the HIIT intervention.
- HIIT required fewer sessions than traditional rehabilitation methods.

## Abstract

Exercise tolerance prior to hematopoietic stem cell transplantation (HSCT) is an important prognostic indicator. Nevertheless, patients with acute lymphocytic leukemia (ALL) before HSCT have reduced exercise tolerance after multiple rounds of chemotherapy. Exercise is encouraged in these patients to prevent reduced exercise tolerance. However, exercise compliance is reduced during chemotherapy. Therefore, we focused on the potential role of high-intensity interval training (HIIT), which improves exercise tolerance but requires fewer interventions. The efficacy and safety of HIIT in patients undergoing chemotherapy remain unknown. Here, we report an exercise intervention that incorporated HIIT in a patient with ALL undergoing consolidation chemotherapy (CC). The patient was a 40-year-old female diagnosed with ALL for whom rehabilitation was implemented after initiation of induction chemotherapy. The patient underwent aerobic exercise on an ergometer (20 min at 50-60% intensity, using the Karvonen method) and weight-bearing resistance training (three sets of 10-20 repetitions at a 4-5 rating on the modified Borg scale) five times a week. The physical function assessment before the third CC session showed decreased exercise tolerance. An HIIT intervention was added as a more effective rehabilitation strategy for the patient. HIIT was performed on an ergometer. The protocol consisted of a 5-min warm-up, three to four sets of alternating between 80-90% peak oxygen uptake (peak VO2) and anaerobic threshold (AT) load for 3 min, and a 5-min cool-down. The number of HIIT interventions was nine of the 21 scheduled for rehabilitation. When HIIT was difficult, aerobic exercise was performed using an ergometer. Exercise tolerance improved without any adverse events, including bleeding, during rehabilitation. In conclusion, practicing HIIT sessions in patients receiving CC appears to safely enhance exercise tolerance with minimal intervention.