Saturday, May 14, 2011

Questions And Answers: Running

I always get a lot of questions on cardio in general and running in particular, so I thought running would make a great topic for my next Q and A.  As always, if you are initiating an exercise program, check with your doctor to make sure it is safe to do so.

Is running a good exercise for weight loss?

Yes and no.  As far as its effectiveness, running is great for weight loss.  You burn a ton of calories.  However, it is high impact and over time can be very tough on the body.  When we run, we put up to 6 times our body weight on our joints.  I’m about 190 lbs, so when I run, I’m pounding my knees, hips, back and ankles with the equivalent of over 1100 pounds of joint stress!  I don’t think our bodies were designed to deal with this level of impact, particularly if you run long distances multiple times per week.  I have found if someone runs long enough and far enough, year after year, they will surely have to deal with some major overuse injuries that can have a negative impact on their ability to engage in physical activity as they age.

I think I want to run a marathon, should I?

I always try to talk my clients out of running marathons.  I get the challenge and sense of accomplishment that goes with running one, but I just don’t think it’s safe.  I’ve already covered the joint stress issue.  Another issue is the effect of that amount of exercise on immune function.  The graph of exercise and immune function is J-shaped.  Your immune system starts to improve with increasing exercise.   However, after a point, immune function starts to decline with increasing exercise.  It even gets to a point below the baseline.  What that means is exercising too much can be worse for your immune system than not exercising at all.  Ever notice how most marathon runners get an upper respiratory infection after the race?  I’m not a fan of any activity that depresses immune function. 

What if I just love to run?

I’ve worked with enough clients over the years to know that running is really addicting and many people will do it despite my recommendation not to.  In this case I would suggest a modified run/walk program.  What I have them do is run for 2 minutes at a pace a little faster than normal and then follow this with 3 minutes of brisk walking.  This interval is repeated throughout the cardio session.  With this strategy, you get the increased calorie burn of running but also break up the impact of continuous running.

Do you advise your clients to run?

Never, I always try to talk them out of it.  If they persist I suggest the run/walk program described above.  I also let them know about lower impact forms of exercise like elliptical training.  This form of exercise will give you a similar calorie burn while protecting the joints. 

1 comment:

Anonymous said...

Hi Tom!

My view of this about running is like your view of the China study :-)

I think running can help with weight loss and maintenance. However, I suggest running on softer surfaces with decent shoes, and mid-foot striking. Also, one must be aware or the tendency to eat more when running and this is not conducive to weight loss.

I have never supported running a marathon. It's too far a distance and can easily cause injuries either in the race, or in the training. There is nothing magical about the distance.

If someone comes to me looking to start a weight loss program, I try to get them walking. If they want to run eventually, I make sure they understand what you have written about.

Dr. J