Exercise to Lose Weight: Is Walking Enough?

It is practically every day that I see an otherwise healthy 30-something person walking out in the community doing exercise for weight loss.  And almost always with a death grip on the BPA-laden plastic water bottle.

Or, I’ll have a patient younger than me who states that they walk for exercise.  Our society and the “experts” have pushed the idea that we should be out walking for our health.  But is this enough?

I’d have to say that this is a pretty strong no.  I always hate to tell a patient who is proud that he or she is walking for exercise that it’s not enough.  Generally, I handle it a little more gingerly, but I still make sure I get my point across.  I try to buffer it by mentioning that, at least, they are probably doing TOO MUCH exercise, just not the right type.

The is an ever increasing body of literature supporting the concept of short burst exercise.  In research, the most common mechanism is stationary bike riding.  Maybe because it’s hard to really injure yourself on one and so it’s safer for the research studies.  Either way, we are looking at a mere 30 seconds of burst-type exercise followed by a rest period.  The rest period is very personalized–it could be 30 seconds if you’re really fit or several minutes if you haven’t gotten your heart rate over 100 since high school gym class.  Repeat 10 times.  For the non-math wizards, this is a total exercise time of 5 minutes.

5 minutes?  That’s just not right.  What about the mantra of 30 minutes of exercise per day?  What about the 10,000 steps on my pedometer?  What about walking during lunch?

Hate to dash all these dogmas in a single article, but I’m going to.  I’ve often thought about why short burst aerobic activity seems to be so powerful for our health and especially heart health.  Here’s what I’ve determined:

It’s about the anaerobic zone.  The hypoxia created.  For me, it’s when I’m on the elliptical looking down at the time wondering if I can cheat and quite at 28 seconds because I’m running out our oxygen.  It’s the reason I don’t hop right down from doing pull ups and hop right up onto the dip station.  I need to re-oxygenate.

If your exercise routine is not intense enough to take you into that zone, it’s not enough as far as I’m concerned.  Keep in mind that, but like the rest period being an individual thing, so is the “burst.”  For a well trained athlete, it could be bleachers at full speed, hammer fists in Krav Maga or a boxing combination flurry.  For the rest of us, breaking the rust free on the exercise bike or ten non-“girly” push ups.  And yes–weight training qualifies.  After all–it is usually the lack of oxygen that gets you to stop a set and the need to catch your breath (maybe not lung-wize, but certainly muscle-wize) before you hop into your next set.

All of this brings me to this particular article.  It is a general overview of a class of compounds (specifically, small segments of messenger RNA) called hypoxamirs.  These compounds are induced by hypoxia (conditions of low oxygen) and make hundreds of changes to the cell to help protect it from the low oxygen.  In the heart, this may include the development of new blood vessels to feed the heart (termed “collaterals”).

Now, it’s too early in the game to say that these hypoxamirs are the compounds that are affected by the short burst aerobic activity, but it certainly seems to fit.  But don’t say it too loudly, or some drug company is going to try to produce a synthetic version so you can just take it as a pill and skip the exercise…