Optimal Timing of a Physical Exercise Intervention to Improve Cardiorespiratory Fitness: During or After Chemotherapy.

Background: Despite the widely acknowledged benefit of exercise for patients with cancer, little evidence on the optimal timing of exercise on adverse effects of cancer treatment is available.
Objectives: The aim of this study was to determine whether an exercise intervention initiated during chemotherapy is superior to an intervention initiated after chemotherapy for improving long-term cardiorespiratory fitness (peak oxygen uptake [VO _2peak ]).
Methods: In this prospective, randomized clinical trial, patients scheduled to receive curative chemotherapy were randomized to a 24-week exercise intervention, initiated either during chemotherapy (group A) or afterward (group B). The primary endpoint was VO _2peak 1 year postintervention. Secondary endpoints were VO _2peak postintervention, muscle strength, health-related quality of life (HRQoL), fatigue, physical activity, and self-efficacy. Between-group differences were calculated using intention-to-treat linear mixed-models analyses.
Results: A total of 266 patients with breast (n = 139), testicular (n = 95), and colon cancer (n = 30) as well as lymphoma (n = 2) were included. VO _2peak immediately postintervention and 1 year postintervention did not differ between the 2 groups. Immediately postchemotherapy, patients in group A exhibited significantly lower decreases in VO _2peak (3.1 mL/kg/min; 95% CI: 2.2-4.0 mL/kg/min), HRQoL, and muscle strength and reported less fatigue and more physical activity than those in group B.
Conclusions: Exercise can be safely performed during chemotherapy and prevents fatigue and decreases in VO _2peak , muscle strength, and HRQoL, in addition to hastening the return of function after chemotherapy. Also, if exercise cannot be performed during chemotherapy, a program afterward can enable patients to regain the same level of function, measured 1 year after completion of the intervention. (Optimal Timing of Physical Activity in Cancer Treatment [ACT]; NCT01642680).
Competing Interests: This work was supported by the Dutch Cancer Society, Alpe d’HuZes (grant DCS 2011-5265). The funder had no role in the design, data collection, management, analysis, interpretation, report writing, and decision to submit the manuscript. Dr Hummel has patents, royalties, and other intellectual properties with Us2.ai (institutional). Dr van der Meer has received research funding from Vifor Pharma (institutional), AstraZeneca (institutional), Ionis (institutional), and Pfizer (institutional); and has received payments or honoraria from Vifor Pharma (institutional), Novartis (institutional), and Pharmacosmos (institutional). Dr Nijland has received research funding from Takeda (institutional) and Roche (institutional); and has performed consulting in an advisory role for Genmab (institutional). Dr de Vries has received research funding from Amgen (institutional), AstraZeneca (institutional), Bayer (institutional), Chugai Pharma (institutional), Crescendo (institutional), CytomX (institutional), Therapeutics (institutional), G1 Therapeutics (institutional), Genentech (institutional), Nordic Nanovector (institutional), Radius Health (institutional), Regeneron, Roche (institutional), Servier (institutional), and Synthon (institutional); and has performed consulting in an advisory role for Daiichi Sankyo (institutional), the National Surgical Adjuvant Breast and Bowel Project (institutional), and Sanofi (institutional). Dr Gietema has received research funding from Abbvie (institutional), Roche (institutional), and Siemens (institutional). Dr Walenkamp has received a grant from the Dutch Cancer Society (institutional); has received research funding from Abbvie (institutional), Bristol Myers Squibb (institutional), Genzyme (institutional), Karyopharm Therapeutics (institutional), and Roche (institutional); and has performed consulting in an advisory role for Polyphor (institutional), Ipsen (institutional), Karyopharm (institutional), and Novartis (institutional). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(© 2022 The Authors.)