HIIT and Dizziness: Safety Assessment Required Before Starting
Do not start a HIIT program while experiencing dizziness until the underlying cause has been identified and addressed. Dizziness may indicate conditions that contraindicate high-intensity exercise, including autonomic neuropathy, orthostatic hypotension, uncontrolled hypertension, or cardiovascular disease—all of which require evaluation before initiating HIIT 1.
Pre-Exercise Evaluation is Mandatory
Before starting HIIT with dizziness present, healthcare professionals must assess for specific conditions that contraindicate high-intensity exercise 1:
- Autonomic neuropathy - can cause exercise-induced blood pressure instability
- Orthostatic hypotension - worsens with intense exercise demands
- Uncontrolled hypertension - poses cardiovascular risk during high-intensity intervals
- Balance impairment - increases fall risk during vigorous activity
- Cardiovascular disease - requires careful history for atypical presentations like decreased exercise tolerance 1
Why HIIT Poses Specific Risks with Dizziness
HIIT involves short bursts of aerobic training at 65-90% VO2peak or 75-95% heart rate peak, creating substantial cardiovascular demands 1. These intensity levels can:
- Exacerbate hemodynamic instability in patients with autonomic dysfunction or orthostatic hypotension 1
- Trigger arrhythmias through sympathetic-vagal imbalance during high-intensity intervals 1
- Worsen dizziness through rapid blood pressure fluctuations between work and recovery intervals 1
Safe Alternative Approach
If you have high cardiovascular risk or unexplained dizziness, start with short periods of low-intensity exercise and slowly increase duration and intensity as tolerated 1. This graduated approach:
- Allows monitoring of symptom response to exercise
- Minimizes risk of adverse cardiovascular events 1
- Permits identification of exercise-induced symptoms before progressing to HIIT
When HIIT May Be Considered
Only after dizziness has been evaluated and controlled should HIIT be considered 1. Even then, medical monitoring may be indicated as individuals intensify their exercise program to ensure safety 1.
Common Pitfall to Avoid
Do not assume dizziness is benign or unrelated to exercise capacity. The 2025 Diabetes Care guidelines explicitly state that healthcare professionals should "be aware of the atypical presentation of coronary artery disease, such as a recently reported or measured decrease in exercise tolerance" 1. Dizziness may represent this type of atypical presentation requiring evaluation before high-intensity exercise.