Is high intensity interval training better than moderate exercise?

High Intensity Interval Training and your health

This week, I want to talk a bit more about exercise because it is a topic that has so many important health implications! I am going to concentrate specifically on High Intensity Interval Training (HIIT) and how it compares regular exercise. I hope to discuss and answer: Is high intensity interval training better than moderate exercise?

We previously talked about exercise and time (click here to read it) and how it can be difficult to add exercise into our busy schedules. I have found HIIT to be a simple answer to the exercise and time dilemma. Even on those days when I REALLY feel I have no time to work out, I can still squeeze these 20 minutes into my day and actually feel like I worked out!

For the last few months, I have been doing the HIIT workouts provided by BeachBody those days when I can’t get to the gym. I must say, they are brief and amazing! Truthfully, if I did not enjoy going to my classes at the gym, I could get the same results from these workouts. I do not get any money for saying this, this is just my opinion. My friend and colleague, Dr. Contreras, is a BeachBody coach and she introduced me to these workouts. You can definitely check them out here and read about her amazing health journey.

As you will discover, you don’t have to exercise for 1 hour or more per day. You can obtain all the benefits and often even more by doing a short HIIT workout!

Ok, let’s get the ball rolling and discuss: Is high intensity interval training better than moderate exercise?

HIIT – How does it work?

Many ways! There is no exact definition, but here are the main ways people do this:

You can do repeated, short (<45 s) to long (2–4 min) bouts of high, but not max intensity exercise.  You could also do short (≤10 s, repeated-sprint sequences) or long (20–30 s, sprint interval session) bouts of all-out sprints, interspersed with brief recovery periods.

You know you are hitting your max intensity when it becomes hard for you to talk while doing the exercise. Also, you start to breathe heavier and, if you have a heart rate monitor, you heart rate goes to or above 80% of its maximum.

If you would like to see what it looks like or are looking to try a free HIIT cardio, check out this 17 minute video. This video consists of 6 simple (but effective) exercises! Each is done for a full 60 seconds with a 20 second low intensity interval in between. This one is purely cardio, but there are many others out there that incorporate weights and strength training in to it. Strength training is also super important for bone health and preventing muscular loss. In addition, when you add weight to your work-outs, you increase intensity and bring your heart rate up faster!

HIIT – Why is it good?

Well, it goes without saying that exercise is vital for our health. This is proven by years of research and nobody can dispute it. We are meant to be active!

Unfortunately, as technology has advanced, we have become very sedentary. Our jobs have us sitting for long time periods. Many of the things we used to do are now done by machines. As this has developed, our rates of obesity, diabetes and heart disease have escalated. We know exercise can help.

As I mentioned, the good part is that you don’t have to do it every day or for long periods to reap health benefits!

Several studies have shown that HIIT is wither as good or, more beneficial for certain parameters, as sustained moderate exercise.

In a study looking at adult patients with type 2 diabetes mellitus, high intensity interval training shows as much improvement in body composition and physical condition as a moderate intensity exercise programs.

Another study showed that six weeks of HIIT significantly improves metabolic health in older males and females by reducing age related risk factors for cardiac and metabolic disease. They found participants experienced increased insulin sensitivity and decrease in plasma cholesterol, LDL, belly fat and percent body fat after six weeks. Interestingly, HbA1c decreased only in males. Additionally, muscle glycogen content increased in both genders. Muscle glycogen is important for muscle growth and recovery, so you don’t want it to be low!

HIIT – Is it as good as the usual exercise routine for longevity?

We know that people who exercise, in general, live longer than those who don’t. This beneficial effect is also seen in people who exercise via HIIT.

A large study from Taiwan showed that 15 min of daily vigorous intensity physical activity resulted in similar all-cause mortality risk reduction (~25%) as 60 min of daily physical activity at moderate intensity.

Another huge study involving 459,833 participants, free from heart disease at baseline, concluded that how fast you walked (48% lower risk) was a stronger independent predictor of overall mortality risk compared with how much you walked (26% lower risk). Therefore, higher exercise intensity seems to promote greater mortality risk reduction than the amount of time/distance.

HIIT- Cardio-respiratory Fitness

Another important concept for health promotion is our level of fitness from a respiratory and heart perspective. This is called cardio-respiratory fitness. As you can imagine, the lower your cardio-respiratory fitness, the higher your risk of death.

Altogether, studies point to exercise intensity, rather than duration or frequency of exercise, as the most important variable in determining cardio-respiratory fitness.

A clinical trial generally reported greater improvements after high- compared to moderate intensity exercise training for diastolic blood pressure, glucose control, and aerobic capacity, but reported no greater effect on improvements in systolic blood pressure, lipid profile, or body fat loss.

HIIT – Insulin sensitivity

A 12-week controlled study in Denmark of high-intensity interval walking for patients with Type 2 diabetes showed it helped control blood glucose levels better than continuous moderate exercise. Interestingly, both groups burned the same number of calories.

Furthermore, studies show improvement in cardiovascular risk factors occurring significantly more with HIIT compared with moderate intensity exercise, including: blood pressure, high density lipoproteins, triglycerides, fasting blood glucose, inflammation, body weight, adiponectin, insulin sensitivity and β-cell function. The authors stated that this should translate into greater decreases in risks of morbidity and all-cause mortality. In case you were wondering, adiponectin is an important protein for glucose regulation and your β-cells are the cells in the pancreas that produce insulin. Both importante for maintaining our glucose balance.

So, is high intensity interval training better than moderate exercise?

Well, lets see. Besides gaining all the benefits of regular exercise, including longevity, compared with regular exercise you have:

1. Increased insulin sensitivity and glucose control
2. Better cholesterol levels
3. Better blood pressure
4. Less inflammation

Now, there are really no excuses not to exercise! As always, make sure you talk with your physician and get checked out before starting any exercise program. Keep it fun, start at your own pace and slowly work your way up. Stationary bikes are a great way to get started! You won’t regret exercising, but you will regret not doing it! 💪🏼

What is your favorite form of exercise? How do you incorporate it into your daily routine?

Have a wonderful, healthy week! ❤