Did you know it is estimated 80% of Americans do not get enough exercise⁶? Why are we not moving enough? A top answer: “I don’t have time”. Many of us have demanding but sedentary jobs with long hours. We have friends, family and other requirements outside of the workspace. How can we better prioritize our health with limited hours in the day? I may have a solution for you. Let’s talk HIIT or High Intensity Interval Training.

What

HIIT is a form of exercise which involves increasing heart rate (HR) to at least 80% of maximum rate**. HR remains elevated for short intervals (seconds to minutes) followed by periods of rest. During rest, HR decreases/stabilizes (~50% max. HR). These intervals are repeated several times.

**To calculate max HR subtract age from 220.

For more on target heart rates check out this post https://lrxwellness.com/how-to-exercise-effectively/.

Why

Studies have found that 10-30 minutes of HIIT is equivalent to longer duration moderate intensity exercise⁷. In other words HIIT is efficient and effective. Additionally, just about anybody can do HIIT. Young. Old. With or without equipment. At home. Inside. Outside. Anyone and anywhere, HIIT is an option.

Benefits

1. Burns more calories
   • Studies have found that HIIT burns ~25-30% more calories than other workouts²
2. Maintain higher metabolic rate
   • Studies have found a higher metabolic rate up to hours after HIIT⁷
3. Burns more fat
   • Target HR of >80% max = anaerobic exercise. Anaerobic exercise burns fat
4. Improves mental health
   • May decrease anxiety and depression symptoms
5. Improves cardiovascular health
   • Decreases resting heart rate
   • Decreases blood pressure
   • Studies have actually found that HIIT may be more effective at lowering blood pressure than other forms of exercise¹
6. Improves blood sugar and insulin resistance⁴
   • Ultimately, reducing the risk of diabetes and improving overall health
7. Improves muscle efficiency
   • Fast-twitch muscle gains = improved overall muscle function
   • Helps perform daily task with ease
8. Improves bone health
   • Strengthens bones (may even improve bone-density)⁵
   • Decreasing risk of osteoarthritis

In Conclusion

High Intensity Interval Training (HIIT) is an efficient and effective workout. It involves increasing the heart rate to at least 80% maximum rate for short intervals. Followed by a brief period of rest. This circuit is repeated several times. There are numerous health benefits to this type of training, some of which may surpass that of typical exercise routines in less time. Anybody can do HIIT but routines should be tailored to fitness level and take medical history into consideration. HIIT should only be performed 2-3 times weekly with at least 48 hours of rest in between. High intensity interval training is a viable solution to not having enough time in the day to meet minimum exercise requirements.

As always, please reach out with questions, comments, or for further discussion.

Lindsey, PharmD, BCPS

References

¹Clark T, Morey R, Jones MD, Marcos L, Ristov M, Ram A, Hakansson S, Franklin A, McCarthy C, De Carli L, Ward R, Keech A. High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity. Hypertens Res. 2020 May;43(5):396-403. doi: 10.1038/s41440-019-0392-6. Epub 2020 Jan 14. PMID: 31937915.

²Falcone PH, Tai CY, Carson LR, Joy JM, Mosman MM, McCann TR, Crona KP, Kim MP, Moon JR. Caloric expenditure of aerobic, resistance, or combined high-intensity interval training using a hydraulic resistance system in healthy men. J Strength Cond Res. 2015 Mar;29(3):779-85. doi: 10.1519 JSC.0000000000000661. PMID: 25162652.

³Harvard T.H. Chan. (2021, November). HIIT (high intensity interval training). The Nutrition Source. https://nutritionsource.hsph.harvard.edu/high-intensity-interval-training/

⁴Jelleyman C, Yates T, O’Donovan G, Gray LJ, King JA, Khunti K, Davies MJ. The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis. Obes Rev. 2015 Nov;16(11):942-61. doi: 10.1111/obr.12317. PMID: 26481101.

⁵Manaye S, Cheran K, Murthy C, Bornemann EA, Kamma HK, Alabbas M, Elashahab M, Abid N, Arcia Franchini AP. The Role of High-intensity and High-impact Exercises in Improving Bone Health in Postmenopausal Women: A Systematic Review. Cureus. 2023 Feb 5;15(2):e34644. doi: 10.7759/cureus.34644. PMID: 36895528; PMCID: PMC9990535.

⁶Piercy KL, Troiano RP, Ballard RM, et al. The Physical Activity Guidelines for Americans. JAMA. 2018;320(19):2020–2028. doi:10.1001/jama.2018.14854

⁷Tinsley, G. (2023, March 15). HIIT benefits: 7 reasons to try high intensity interval training. Healthline. https://www.healthline.com/nutrition/benefits-of-hiit#bottom-line