What it is
Regulatory status: exercise practice
Mechanism evidence: human
At a glance
What it is, why people use it, the evidence, and what to know before trying it.
Why people use it
- Increase VO2 max
- Aerobic performance
- Cardiometabolic fitness
Evidence at a glance
High-intensity intervals can improve VO2 max efficiently, but protocols are not interchangeable. A 10-second hard and 20-second rest pattern is one personal session and has not been established as the uniquely best dose.
Confidence: strong
Practice safety
Situations where this practice may need modification or professional guidance.
Very hard intervals can provoke musculoskeletal injury, faintness or cardiovascular symptoms. They require appropriate warm-up, recovery and progression; chest pain, fainting or unusual breathlessness warrants medical assessment.
- Unstable cardiovascular disease
- Acute illness or injury
- Unexplained exertional symptoms
- Severe exertional discomfort
- Muscle soreness
- Injury
- Dizziness
Forms and variants
This review does not automatically apply to:
- a VO2 max measurement without training
- all sprint training
- steady-state aerobic exercise
Seen in protocols
Public protocols that include VO2 max training. Open one to see the full context and source.