HIIT training can improve cardiovascular endurance, preserve muscle mass, and help manage blood sugar levels. This article explains the benefits of HIIT training, recommended work-to-rest ratios, and how to safely include HIIT workouts in your routine.
The Theory
HIIT stands for High Intensity Interval Training. HIIT is based on alternating short bursts of intense exercise with recovery periods of lower-intensity activity or rest. This approach pushes the body to work near its maximum capacity, challenging the cardiovascular and muscular systems more than traditional steady-state exercise. HIIT is designed to boost aerobic and anaerobic endurance, increase calorie burn, and improve metabolic rate even after the workout is complete, known as the "afterburn" effect. The intervals' intensity and recovery stimulate fast adaptations, enhancing overall fitness in a shorter workout time.
Cardiovascular Improvement
Traditional cardio is great for health benefits. You will lose a few pounds and make small cardiovascular gains by walking, jogging, biking, etc. But if you really want to see BIG gains, HIIT has been proven to give you the most bang for your buck! A study by Hazell et al. (2014) showed big improvements on a wide variety of measured metrics. The women who participated in sprint interval training improved maximal oxygen consumption, increased muscle mass, higher top speed, lost body fat, and lost inches around their waist. Other than HIIT, we've also created our Top 10 tips for losing weight.
Preserve Your Muscle
All exercise will help you lose weight, BUT, the best type of weight loss is fat loss. We've worked hard to increase or keep our muscle. The last thing we want to do is lose muscle because we carelessly followed someone else's workout plan and diet strategy. Rose et al. (2025) showed that interval training was best for preserving muscle. The interval training group was the only group that maintained or improved muscle mass. The subjects who used moderate or low intensity training lost muscle mass during the study.
HIIT and Type 2 Diabetes
Another benefit of HIIT training is the management of Type 2 diabetes. Diabetes is a huge epidemic in the world and especially the United States. Of course macros are important but HIIT can also be part of the solution. Jelleyman et al. (2015) did a review of 50 studies on the effects of high intensity interval training on glucose regulation and insulin resistance. The subjects in the HIIT training protocol showed significant improvements in fasting glucose compared to the control groups.
Work to Rest Ratio
The benefits of HIIT are undeniable. But the big question is, how long do you work, how long do you rest? This is where it gets tricky. There isn't enough evidence to show one work:rest ratio being superior to other ratios. My suggestion would be to start slow, and increase the intensity as your endurance improves. Start with a 1:5 work to rest ratio. Therefore, sprint/jog for 10 seconds and walk/rest for 50 seconds. Do this for about 10 to 15 minutes.
After a few weeks, you will be able to see and feel the improvements. Then you can change the work:rest ratios to 1:3 or even 1:1. The more you work, the more gains you will see in your cardiovascular fitness. But don't forget to rest and recover. It's important to rest your body to maximize your gains.
HIIT Boxing
Sprints are great! In fact, most people who choose HIIT training will either choose battling ropes or sprints. But, the newest HIIT workout is hitting the heavy bag. A great combination may be jump rope and boxing. Jump rope for 30 seconds, hit the bag for 30 seconds, and rest for 1 minute. Try this ratio for 15-20 minutes.
Does boxing have the same effect as some of the other exercises? Cheema et al. (2015) compared a boxing group against a walking group, and it turned out that the boxing group lost more weight, and enjoyed the experience much more than the walkers. The boxers showed improvements in body fat percentage, systolic blood pressure, and VO2 max. So, if you want to change it up, but still get maximum benefits, feel free to include boxing as one of your HIIT workouts.
HIIT with Music
HIIT takes a lot of energy, and I certainly couldn't do it without music. If you're like me, and you need more motivation to get moving, try listening to music. Bartolomei et al. (2015) showed that the subjects who listened to their own playlist produced more work than the subjects who didn't listen to music. So grab your playlist, your water bottle, your towel, and let's get moving!
Sources:
Bartolomei, Sandro, et al. “Effects of Self-Selected Music on Maximal Bench Press Strength and Strength Endurance.” Perceptual And Motor Skills, vol. 120, no. 3, June 2015, pp. 714–721.
Cheema, Birinder S., et al. “The Feasibility and Effectiveness of High-Intensity Boxing Training versus Moderate-Intensity Brisk Walking in Adults with Abdominal Obesity: A Pilot Study.” BMC Sports Science, Medicine and Rehabilitation, vol. 7, Jan. 2015, p. 3.
Hazell, Tom J., et al. “Running Sprint Interval Training Induces Fat Loss in Women.” Applied Physiology, Nutrition, And Metabolism = Physiologie Appliquee, Nutrition Et Metabolisme, vol. 39, no. 8, Aug. 2014, pp. 944–950.
Jelleyman, C., et al. “The Effects of High-Intensity Interval Training on Glucose Regulation and Insulin Resistance: A Meta-Analysis.” Obesity Reviews: An Official Journal Of The International Association For The Study Of Obesity, vol. 16, no. 11, Nov. 2015, pp. 942–961.
Rose, Grace et al. “Exercise intensity influences body composition: a 6-month comparison of high-intensity interval, moderate- and low-intensity training among healthy older adults.” Maturitas vol. 203 (2025): 108763. doi:10.1016/j.maturitas.2025.108763