Not Just a Man's World

Weight loss – part 7

This is the seventh part in a series about weight loss including diet, exercise, measuring your success and keeping the weight off when you stop.

Last week I worked through some thoughts about using resistance training for weight loss.  However, even with the best will in the world the fitness professionals seem to be agreed that you’ll only get optimal results if you do some cardio as well.

The different types of cardio

Essentially I tend to see cardio for weight loss as fitting into three main categories:

1. Steady state: this includes things like running on a treadmill or cycling for a long period of time, whether that is half an hour, an hour or possibly even longer.
2. High-intensity interval training (HIIT): within this category there are all sorts of things including Tabata-style workouts, bike intervals, hill sprints, weighted cardio split into short periods of intense effort – the list is endless.
3. Non-exercise Physical Activity (NEPA): this refers to general physical activity that you do as part of a normal day.  Things like taking the stairs and walking to the car.  Increasing levels of NEPA through plenty of small changes, such as taking the stairs instead of the lift or parking at the opposite side of the car park to the shop entrance, can make significant differences to the number of calories that you burn over the course of a full day. 

For this post I am going to focus on HIIT.

Why use interval training?

The short answer is that HIIT works.  Have you ever studied pictures of marathon runners alongside images of sprinters?  The sprinters are more muscular and leaner than the marathon runners.

I would speculate that this goes back to the point I made last week about resistance training for weight loss.  If you are still forcing your muscles to work hard then your body isn’t going to strip that muscle off in an effort to reduce the number of calories it needs.  Just as resistance training requires plenty of muscles, so too does HIIT.

If you don't look like this at the end, the intensity probably isn't high enough!

What are the benefits of HIIT

There are plenty of additional benefits of HIIT other than the broad brush idea that it is good for weight loss.  I’ve outlined some key benefits below.

Afterburn (again)

An article in Bodybuilding.com highlighted a study from 1985 which concluded that high-intensity training (note, not necessarily intervals) increased metabolism for 24 hours afterwards.  This is the afterburn effect I wrote about last week and is essentially highlighting that high-intensity exercise can come in many forms, not just standard resistance training but also cardio (as interval training).

Save yourself some time

On top of that, there is a definite time consideration.  Science Daily recently published an article that discussed the benefits of slightly less intense HIIT, working at 95% of maximal heart rate.  That’s probably where I’m at when I do my weighted cardio routines. 

The biggest benefit that the Science Daily article highlights is that interval training doesn’t take as long as steady state exercise.  To burn the same amount of calories from a brief HIIT session (ignoring the potential afterburn benefits of HIIT) you would have to spend hours doing steady state cardio.  Since steady state cardio doesn’t tend to stress the muscles that is hours of exercise telling your body that it can afford to get rid of some muscle.

General health benefits

If all of that isn’t enough to convince you that HIIT is far superior to steady state cardio when you are trying to lose some weight then consider the general health benefits.  A study carried out by Nybo et al earlier this year found that high-intensity training (using intervals) gave benefits of improved cholesterol levels and reduced resting heart rate in addition to the expected fat loss.

Another study by Guimaraes et al, also published earlier this year, found that interval training gave significantly improved blood pressure levels in the test subjects when compared to steady state cardio.

So with all these additional benefits on top of the excellent weight loss results that HIIT gives, it seems foolish to carry on spending hours on the treadmill.

I think I’ve probably covered enough about HIIT to convince a few people.  Next week I’ll wrap up with a very brief post on a few other exercise related topics before we move onto some general weight loss issues.  Let me know if there is anything you would like me to cover in this series which doesn’t seem to be coming up.

Related posts:

1. Resistance training for weight loss
2. Blog-watch: high protein diets
3. What exercise is best for losing weight? – Part 2
4. What exercise is best for losing weight? – Part 1