Photobiomodulation Combined with Moderate or High-Intensity Interval Training on Oxygen Consumption and Exercise Tolerance in Patients with Heart Failure

Busin D, Franzoni LT, Turella D, Tairova OS, Silveira ADD, Stein R, Amorim GL, Lago PD, Nunes RB

Question

Does adding photobiomodulation to moderate continuous or high-intensity interval aerobic training improve VO2peak and exercise tolerance in patients with heart failure?

Summary

In a nonrandomized heart-failure rehabilitation trial, 10 weeks of aerobic training improved treadmill tolerance measures, especially in the high-intensity interval training group, but adding photobiomodulation did not provide clear additional benefit. One participant did not complete the intervention for personal reasons; formal adverse-event details were not reported.

Methodology

Patients with clinical heart failure referred to a cardiac rehabilitation program.
49 participants.
Treadmill.
Work intervals: 4 min at 90%-95% HRR.
Recovery: 3 min active recovery with light walking.
Intensity: 90%-95% HRR.
At least 38 min including warm-up; full cooldown not clearly reported.
3 sessions/week.
10 weeks.
Nonrandomized clinical trial with five groups
VO2peak, Exercise tolerance, and Ventilatory efficiency were tracked.

Outcomes

Exercise tolerance

Training groups improved treadmill speed and grade, especially HIIT.

Abstract: time-to-exhaustion performance speed p=0.05 and grade p<0.01.

Improved

VO2peak

HIIT showed an oxygen-consumption increase in abstract, but full paper group comparisons were not significant.

Abstract HIIT mean difference 1.80 +/- 0.59 mL/kg/min, p=0.002; full text states no significant between-group VO2peak differences.

Mixed

PBMT add-on

PBMT did not add relevant benefit to training.

Post-hoc comparisons did not reveal significant differences between groups with and without PBMT.

No clear change

Insights

Clinical 4 x 4 HIIT can be delivered with HRR targets in stable HF rehabilitation.
PBMT should not be assumed to add benefit without better randomized evidence.
Consumer apps should treat this as clinical-background evidence, not a direct prescription.

Limitations

Nonrandomized design
Small groups
No sham PBMT group
No PBMT-only group
Control group selection bias
Trial not publicly registered
Adverse-event reporting unclear

Safety

Formal adverse events were not reported.
One participant in the HIIT-PBMT group did not complete the intervention for personal reasons.
Participants were clinically stable heart-failure patients in a cardiac rehabilitation program with continuous heart-rate monitoring and real-time intensity adjustment.