Friday, February 25, 2011

Fat Loss Theory: Running and Aerobics (Part 2)

Contrary to popular belief, running (or any type of steady state cardio or aerobic exercise, for that matter) is not at all necessary when it comes to fat loss. In fact, I would go as far as to say that aerobic exercise is just about as far down the usefulness totem pole as it gets when it comes to fat loss. Of course, the reason for this has already been covered in Part 1 of this series. When it comes to absolute intensity, the main determinant of how effective an exercise program will be for fat loss, aerobic exercise simply cannot keep up with other methods.

However, aerobic exercise isn't necessarily terrible either. The real problem, outside of a small absolute intensity (by definition), is with limiting factors.

There are several limiting factors that you should familiarize yourself with when it comes to aerobics. The most relevant ones for this discussion are:

1. Time
2. Posture/Injury

If you are like most people, you do not have 12 hours to train every single day. Even if you did, you probably wouldn't want to. When it comes down to it, you probably only have enough time (or motivation) to get in about an hour of exercise a day at most. If you actually want to make a dent in your physique given this time frame, you should probably be picking a high intensity activity OR be training with the long term focus of improving your intensity capacity. Running and other forms of aerobic exercise simply take too much time to be an ideal method for fat loss.

The most important factor, in my opinion, in determining whether your exercise program will be successful long term is your ability to stay healthy. If you can't stay healthy, you can't train optimally (or at all). The most common training injuries are repetitive motion injuries. The Law of Repetitive Motion does a great job of explaining the mechanism behind soft tissue injuries and will be very useful for you to review in order to understand this discussion.

There is no greater violator of the law of repetitive motion than aerobic exercise! Runners are among the most oft injured people who participate in regular exercise. To help prove this, I turn to research (something I rarely do)

A study by Hamill in 1994 (1) found the following injury rates per 100 contact hours:
Weight Training: 0.0012
Youth Soccer: 6.2
Basketball: 1.02
PE Class: 0.18

Here are the numbers on recreational running:

0.36-0.56 injuries per 100 contact hours (2)

So, if we use the most conservative number, 0.36, we would come to the conclusion that weight training is 300 times safer than running.

With running and aerobic activity, the only way to increase your intensity is to run faster (requires more strength) or train longer (greater repetitions). According to the law of repetitive motion, this is going to result in a greater potential for injury. Not only that, but the greater the intensity and duration of aerobic exercise, the more negative the effects are on muscular strength, size, and power! Not only is that not conducive to fat loss (as it decreases your intensity capacity), but it increases your risk of injury (again, see The Law of Repetitive Motion). If you throw in poor running form (and let's face it, very few people have perfect mechanics), the more you run, the more you are going to deviate from ideal posture, further contributing to your injury risk.

Anyway, the only logical conclusion that I can reach is that running or other forms of aerobic exercise should not be the centerpiece of any fat loss program. As usual, there are exceptions to this rule (one of which is covered in Chapter 8 of THE Theory of Fat Loss), but those are few and far between and beyond the scope of this discussion.

What are your thoughts? Have you had success with running or aerobic exercise? Have you been frustrated by it? Do you have an injury story? Let me know. Leave a comment below.

1. Hamill, B. (1994). Relative Safety of Weightlifting and Weight Training. J. Strength Cond. Res. 8(1):53- 57.
2. Sports Injuries: Their Prevention and Treatment. Peterson and Renstrom. 2001.


  1. I used to run cross country in high school. I ran myself into a stress fracture. I was probably running on it for awhile before it became unbearable to walk. I had to be on crutches for 3 months.

  2. Yeah, I also was a XC runner... every season at least half the team had an injury at one point or another. I have a very thorough awareness of running, and that is probably why I feel comfortable writing about it.


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