James Haynes, M.D.Q: I'm interested in starting a new workout regimen, and someone I know suggested I incorporate HIIT into my routine. What is HIIT, and is it safe for my body?
A: High-intensity interval training (HIIT) is a form of exercise that involves short bursts of intense activity, followed by a period of rest or lower-intensity activity. This type of training pushes your heart to its maximum performance capability for a short time and then allows your body time to recover. It requires you to push yourself to maximum or near-maximum effort, which is why HIIT sessions are generally much shorter than other forms of cardiovascular exercise (e.g., a long run where you ration your energy). Generally, HIIT workouts require going all out on an activity for 30, 60 or 90 seconds, followed by an equal or greater amount of time at rest. The intervals spent at rest are just as important as the intervals spent engaging in high-intensity activity.
HIIT involves working your hardest, which can help boost endurance and burn body fat. The elevated heart rate and increased oxygen intake can be good for cardiovascular-respiratory health and can result in burning more calories. Monitoring your heart rate is an important component of this type of exercise, to ensure that you work hard but avoid overworking.
Although it has a wealth of health benefits, HIIT is not the only form of training you should be engaged in. Balance HIIT workouts with days of more moderate, sustained cardiovascular exercise, as this will help long-term endurance. If you are used to working out and want to incorporate something new, HIIT is a great option for a challenging change of pace. If you are brand new to working out, it may be a better to get into the habit of various forms of exercise and to establish your active and resting heart rates, before engaging in HIIT.
As with any exercise program, make sure to check with your doctor before starting HIIT. It is important to be aware of the individual risks and benefits it may have for you and to make sure you engage safely. Additional benefits of HIIT may include improved blood pressure control and insulin sensitivity for those with diabetes and prediabetes.
- James Haynes, M.D., UT Family Practice Center; member, Chattanooga-Hamilton County Medical Society