The long-term health benefits of running a marathon - and how it could actually be good for your knees

Running a marathon is no easy task, but is it really as hard on your body as many people think? We spoke with Dr. Reed Ferber, director of the Running Injury Clinic, to find out if all of that hard work is healthy and what the health implications are of running 26 miles. Following is a transcript of the video.

Reed Ferber: My name is Dr. Reed Ferber. I hold a PhD in biomechanics, which is the physics of human movement.

So, marathon running is actually protective for your knees. There's been a few long-term studies. Meaning they followed runners who run marathons and run marathons on a regular basis, and then they come back to them 20-30 years later.

It actually decreases all-cause mortality, meaning these people are living longer. They have fewer diseases such as cardiovascular disease, diabetes. But it's actually protective for their knees. They have fewer instances of osteoarthritis. Which is when the bones wear away.

So running, in general, is extremely beneficial. It's very healthy for you. And it protects against other diseases.

Running isn't bad for your joints. It's not bad for your ankle, your knee, or your hip joints. However, if you already have an injury, then you are far more likely to get injured moving forward with a training program.

So arthritis, for example, where there's bone-on-bone contact and a degradation of the bone and the cartilage in between, where those two bony surfaces come together. Certainly, you don't want to cause increased forces within that joint itself. But that's not to say that you can't run. If you get your muscles good and strong to support that shock wave that travels up to your body with every step, then you can mitigate or minimize those forces just fine.

Engaging in a regular running program is healthy for your heart. It keeps your weight down. So running, in general, is really good for you. You just don't want to do too much, too fast, too soon. That's how you get injured.

The best way to train for a marathon is to stick to the program because most of the programs have been designed to try to accommodate for slow increases, about a 10% increase per week in volume, but you should also be augmenting that with swimming, biking, or lifting weights. Cross training is really critical to help prevent injuries.