Effects of high-intensity interval training on fatigue and quality of life in testicular cancer survivors
Question
Does 12 weeks of supervised high-intensity interval training improve patient-reported outcomes in testicular cancer survivors compared with usual care, and are effects mediated by cardiorespiratory fitness or moderated by baseline clinical characteristics?
Summary
In a phase II randomized controlled trial, 63 testicular cancer survivors were assigned to 12 weeks of supervised treadmill high-intensity interval training or usual care. The HIIT group improved cancer-related fatigue, self-esteem, and several health-related quality-of-life domains after training, with fatigue and vitality benefits persisting at 3-month follow-up. Training adherence and target-intensity achievement were very high, and no exercise-related serious adverse events were reported.
Methodology
- Post-treatment male testicular cancer survivors with confirmed stage I-IV history, excluding regular vigorous exercisers and those with uncontrolled cardiovascular or psychiatric conditions.
- 63 participants.
- Uphill treadmill walking or running.
- Work intervals: 4 min.
- Recovery: 3 min active recovery.
- Intensity: 75%-95% VO2peak for work intervals; recovery 5%-10% below ventilatory threshold.
- 35 min.
- 3 sessions/week.
- 12 weeks.
- Prospective two-arm phase II randomized controlled trial with post-intervention and 3-month follow-up assessments.
- Cancer-related fatigue, Health-related quality of life, Psychosocial functioning, and Cardiorespiratory fitness were tracked.
Outcomes
Cancer-related fatigue
HIIT significantly improved post-intervention fatigue compared with usual care, and the effect persisted at 3-month follow-up.
Post-intervention adjusted between-group mean difference 4.4 points, 95% CI 1.5 to 7.3, p=0.003; follow-up p=0.031.
Self-esteem
HIIT significantly improved self-esteem at post-intervention compared with usual care.
p=0.029
SF-36 HRQoL domains
HIIT improved mental component score, vitality, social functioning, general health, and role-physical at post-intervention; vitality persisted at follow-up.
MCS p=0.034, vitality p=0.001, social functioning p=0.011, general health p=0.016, role-physical p=0.048; 3-month vitality p=0.015.
Depression, anxiety, stress, sleep quality, and selected SF-36 domains
No significant effects were observed for depression, anxiety, stress, sleep quality, physical functioning, bodily pain, role-emotional, or physical component score.
Depression p=0.81, anxiety p=0.19, stress p=0.22, sleep quality p=0.15, physical functioning p=0.77, bodily pain p=0.41, role-emotional p=0.36, PCS p=0.34.
Cardiorespiratory fitness
HIIT improved VO2peak relative to usual care, and VO2peak changes mediated selected PRO improvements.
VO2peak improved by 3.7 ml O2/kg/min, p<0.001; mediation evidence reported for MCS, mental health, CRF, and vitality at p<0.05 or p<0.10 depending on outcome/timepoint.
Insights
- A supervised 4 x 4-minute HIIT protocol can be feasible and highly adherent in selected testicular cancer survivors.
- Fatigue and vitality are stronger practical targets from this study than depression, anxiety, stress, or sleep quality.
- Clinical HIIT programming should include screening, supervision, and progression rather than direct unsupervised transfer.
Limitations
- No outcome assessor blinding.
- Low initial response rate and possible self-selection bias.
- Limited 3-month follow-up.
- Variable time since diagnosis.
- Small sample size for PRO analyses.
- Loss to follow-up at 3 months.
- Baseline clinical fatigue imbalance.
- No attention-control comparison group.
- Exploratory mediation and moderation analyses.
Safety
- No exercise-related serious adverse events were reported or observed.
- Participants achieved 98% of target work-phase heart rates and attended 99% of sessions under one-on-one supervision.