High-intensity interval training (HIIT) has surged in popularity over the last decade. But what exactly is HIIT, and why has it become such a buzzword? Let’s dive into the mechanics, benefits, and practical applications of this workout methodology.
Disclaimer: The information provided in this article is for informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. If at any point during exercise you begin to feel faint, dizzy, or have physical discomfort, you should stop immediately and seek professional advice.
High-intensity interval training is a cardiovascular exercise strategy alternating short periods of intense anaerobic exercise with less intense recovery periods. Typically, a HIIT session lasts from 20 to 30 minutes and incorporates a variety of exercises, including sprinting, biking, jump rope, and body weight movements.
The key characteristic of HIIT is the intensity during the high-effort intervals, which are performed at 80-95% of a person’s estimated maximal heart rate. Your maximal heart rate is the maximum number of times your heart will beat in a minute without overexerting yourself.
The allure of HIIT lies in its efficiency and effectiveness. HIIT delivers results in shorter sessions compared to sessions that are more moderate in intensity. Studies suggest that HIIT also improves oxygen consumption, reduces your resting heart rate and blood pressure, and improves insulin sensitivity, reducing risk of diabetes (Gibala et al., 2012; Kilpatrick et al., 2014; Nicolò & Girardi, 2016; Atakan et al., 2021). HIIT has also been shown to improve cognitive abilities - our ability to think, reason, plan, remember and respond to the world around us (Alves, et al., 2021; Atakan et al., 2021; de Lima et al., 2022).
Before starting any new exercise programme, it’s wise to consult with a healthcare provider, especially if you have pre-existing health conditions.
Begin slowly
Start with shorter workouts (10-15 minutes) and gradually increase the duration as your fitness improves.
Master the form
Before attempting HIIT, ensure you’re comfortable with the form of each exercise. This reduces the risk of injury and ensures you get the most out of your workout. Try a class or trainer at least once if you are unsure.
Use interval timers
Many free apps can help you time your intervals. Begin with longer low-intensity intervals and shorter high-intensity bursts, gradually adjusting as you become more comfortable.
Listen to your body
It’s normal to feel challenged during HIIT, but you shouldn’t feel overwhelmed. If you’re unable to speak or experience sharp pain, stop and adjust your intensity.
Stay hydrated
Drink plenty of water before, during, and after your workout to stay hydrated.
Rest and recover
Allow at least one full day of rest between HIIT workouts to let your body recover.
Alves, A. R., Dias, R., Neiva, H. P., Marinho, D. A., Marques, M. C., Sousa, A. C., Loureiro, V., & Loureiro, N. (2021). High-intensity interval training upon cognitive and psychological outcomes in youth: A systematic review. International Journal of Environmental Research and Public Health, 18(10), 5344.
Atakan, M. M., Li, Y., Koşar, Ş. N., Turnagöl, H. H., & Yan, X. (2021). Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective. International journal of environmental research and public health, 18(13), 7201.
de Lima, N. S., De Sousa, R. A. L., Amorim, F. T., Gripp, F., Diniz E Magalhães, C. O., Henrique Pinto, S., Peixoto, M. F. D., Monteiro-Junior, R. S., Bourbeau, K., & Cassilhas, R. C. (2022). Moderate-intensity continuous training and high-intensity interval training improve cognition, and BDNF levels of middle-aged overweight men. Metabolic brain disease, 37(2), 463–471.
Gibala, M. J., Little, J. P., Macdonald, M. J., & Hawley, J. A. (2012). Physiological adaptations to low-volume, high-intensity interval training in health and disease. The Journal of physiology, 590(5), 1077–1084.
Nicolò, A., & Girardi, M. (2016). The physiology of interval training: a new target to HIIT. The Journal of physiology, 594(24), 7169–7170.
Kilpatrick, M. W., Jung, M. E., & Little, J. P. (2014). High-intensity interval training: A review of physiological and psychological responses. ACSM's Health & Fitness Journal, 18(5), 11-16.