A pilot study examining the effects of low-volume high-intensity interval training and continuous low to moderate intensity training on quality of life, functional capacity and cardiovascular risk factors in cancer survivors
Question
To examine the effects of low-volume high-intensity interval training versus continuous low-to-moderate intensity training on cardiovascular disease risk, quality of life, functional capacity, and related health outcomes in cancer survivors.
Summary
This small randomized pilot study compared 12 weeks of supervised low-volume HIIT with supervised continuous low-to-moderate intensity training in female cancer survivors within 24 months of diagnosis. Both programs were associated with improvements across several quality-of-life, functional, anthropometric, and cardiovascular risk variables. The HIIT group improved more on the six-minute walk test, attended sessions well, and reported no adverse effects, but the study was very small, lacked a non-exercise control group, and did not control diet.
Methodology
- Female cancer survivors within 24 months post-diagnosis, post-treatment, insufficiently active, and medically cleared for supervised exercise.
- 16 participants.
- Cycle ergometer or treadmill.
- Work intervals: 30 seconds.
- Recovery: 1 minute between intervals.
- Intensity: At least 85% maximal heart rate, estimated from 220 minus age.
- Approximately 18.5 minutes once at full protocol, including 5-minute warm-up and 5-minute cool-down.
- 3 sessions per week.
- 12 weeks.
- Randomized supervised pilot intervention comparing two active exercise programs.
- Six-minute walk test, FACT-G quality of life, Blood pressure and central hemodynamic measures, and Pulse wave velocity were tracked.
Outcomes
Overall dependent variables
Significant time improvements were observed for 13 of 23 dependent variables.
p <= 0.05; ES 0.05-0.61.
Six-minute walk test
LVHIIT improved more than CLMIT: CLMIT changed 1.16% whereas LVHIIT changed 18.53%.
Group-by-time interaction; partial eta squared 0.50; abstract reports p <= 0.01.
Quality of life
FACT-G improved in both groups, with a larger percent change in LVHIIT.
CLMIT 81.25 to 85.88, 6.14% (95% CI 1.84 to 10.45); LVHIIT 77.63 to 89.50, 17.44% (95% CI 6.65 to 28.23).
Training heart rate and adherence
LVHIIT achieved average interval heart rate of 144.76 bpm and high session compliance was reported.
Interval HR 144.76 (SD 10.34) bpm; recovery HR 118.34 (SD 8.70) bpm; overall compliance 93.75% (83.33%-100%).
Adverse effects
No adverse effects were reported by participants during the study.
Insights
- A low-volume interval structure with only 3.5 minutes of hard work per session can be feasible in selected, supervised cancer survivors.
- Progressing from three to seven intervals over the first five sessions is a practical ramp for deconditioned or clinical users.
- Clinical-population HIIT programming should preserve screening, monitoring, warm-up, cool-down, and conservative progression.
Limitations
- Small pilot sample.
- No non-exercise control group.
- No dietary intake control.
- All randomized completers were female cancer survivors, limiting generalizability.
- Supervised equipment-based setting limits direct translation to unsupervised app workouts.
Safety
- No adverse effects were reported by participants.
- Participants required medical screening and physician clearance.
- Sessions were supervised with heart-rate and blood-pressure monitoring.