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"How long can one safely be at [his or] her max heart rate?"
–Tiffany Tamm, via Facebook
Because of the primary types of fuel being burned (a combination of ATP/CP and muscle glyogen), maximum heart rate is only sustainable for short bursts ranging from 10 to 60 seconds. After that, your body needs to downshift in speed and start burning more oxygen.
But instead of focusing on how long one can stay at your HRmax, I would recommend shifting your focus to the bigger issue, which is how quickly you can recover from high-intensity exercise, even during the rest periods within your workout. Whoever recovers the fastest, wins — and lives the longest.
If you are a competitive athlete, you will probably push your heart rate harder, more often. But it is still only as you return to approximately 60 to 80 percent HRmax that you regain access to your fine and complex motor skills, as well as full cognitive function. It is to that point, therefore, that you are trying to return after reaching HRMax.
Learn to reactivate your body's relaxation and recuperation response with these tips. Incorporate them during the rest periods of your interval workouts.
Focus on exhaling fully but without forcing the air out. The release of pressure in your abdomen will help you recover more quickly.
Picture a calming scene to help slow your heart rate.
Repeat a self-command such as "focus" to bring your attention to the task of recovery.
About the Expert
Scott Sonnon is the founder of TACFIT, a training system that combines intensity with heart-rate recovery methods. He is a martial arts expert, fitness coach and wellness speaker.