This will not be news to those who follow other Paleo blogs, but it might be new for a lot of cycling types out there. According to one story recently reported, marathon running may not be as heart healthy as Americans have come to think in the last 40 years:

ATLANTA — A group of elite long-distance runners had less body fat, better lipid profiles, and better heart rates than people being tested for cardiac disease, but, paradoxically, the runners had more calcified plaque in their heart arteries, according to a study reported here.

In other words, marathoners look like the picture of health:  skinny, low cholesterol, low resting heart rate. But cutting against the grain of conventional dietary wisdom, they have more artery clogging plaque than more more sedentary types. Whether this is due to the actual stress associated with marathon running, or the high-carb diet that is typical of marathon runners, is unclear.

This comes on the heels of a german study that indicated that marathon runners are more likely to have heart problems than their otherwise low weight and “good” lipid profiles would suggest. You can find a much more detailed discussion of these studies over on Kurt Harris’s PaNu Blog here and here. Kurt is an MD, and does a much better job outlining them than I could.

The point is that there seems to be an increasing amount of evidence (at least for this layperson) to suggest that our bodies consider “ultra” and long-distance cardio activities to be stressful and traumatic events (and not in the good way that all exercise stresses the body). At the least, excessive cardio is not making you healthier. At worst, these long-distance activities might actually do damage over the long term.

That might be obvious to some–moderation almost always seems like the way to go in health matters–but it’s a bitter bill to swallow for exercise junkies who have been trying to go stronger and longer in their quest for fitness, personal challenge, etc.

The good news is that there is also an increasing amount of evidence to suggest that when it comes to fitness gains, quality/intensity may be more important than quantity. Sprinting, intervals, and shorter periods of ass kicking have many of the same (positive) physiological effects on your body as doing the long miles, as per this admittedly limited study.

Applying this to cycling, it would suggest we should all do a lot more casual riding at a mellow, fat-burning pace (say under 75% of max heart rate). The human body was designed to move slowly over long distances with little harm, and this sort of riding is the equivalent of a brisk walk. The everyday, practical sort of riding being promoted by the good folks at Rivendell comes to mind.

When you want to kick it up a notch, hill work, intervals, and other intense forms of training for briefer periods will keep you in top form. But for many, “intervals” have all the regimented appeal of going to boot camp. Biking is supposed to be fun, right?

Well, there is a form of biking that incorporates a lot of these principles while still being exciting: it’s called mountain biking. It involves short bursts of power and sprints to clean hills and other obstacles, often followed by downhills and periods of rest. Call them “intervals” or “hill work” if you like, but most of us just call it fun.

To be sure, you can overdo it in mountain biking just like anything else: 24 hour events and hardcore XC race training come to mind. But in the long run, the kind of mellow mountain biking that most of us do on the local trails every weekend is probably more heart healthy than long-distance road cycling, or a 4-hour club ride done at 90% of maximum heart rate.

The other advantage to mountain biking– getting yourself “out there” and into places like this:

palm canyon
That’s me doing the Palm Canyon epic outside of palm springs.