The world is a scary place right now. Not since the Cuban Missile Crisis has the threat of nuclear war been this real. What the world will look like following nuclear conflict is hard to say. But one thing is for certain: natural selection.

Natural selection, put another way, is the survival of the fittest. And in a post apocalyptic wasteland, the fittest will survive. But what kind of fitness gives you the best chance at survival? Let’s look at two popular types of training and see how each would fair in post apocalyptia.

First up? Bodybuilding. No trend in fitness or exercise, it would seem, has benefitted more from the rise of social media than bodybuilding. A scene that was once largely underground has moved closer to the mainstream, thanks in large part to social media platforms like Instagram. In “Deadlifts and Selfies: How Social Media Shaped the Modern Bodybuilder,” Victoria Chan of Vice looks at Toronto bodybuilder Ronaldo Gairy, who she says is “part of a new generation of athletes that is driving the renewal of the modern bodybuilding industry through social media, regularly updating fans with body selfies, training videos, and pictures of protein powder.”

In the modern era, bodybuilding is definitely excelling. The sport has never been more popular, and aspiring professional bodybuilders have never had more opportunities for success. But would that success translate well to a world ravaged by nuclear fallout? Probably not.

All the muscles in the world can’t protect you from radiation poisoning. What that muscle WILL do is slow you down. Good luck outrunning a pack of rabid wolves at 250 pounds. Sure, there will be times when being bigger and stronger than your average wastelander will come in handy. But for the most part, a bodybuilder would be woefully unequipped for the long haul. Maintaining a bodybuilders physique requires ingesting an inordinate amount of protein, which will be hard to come by in the aftermath of the fall of society.

So if bodybuilding isn’t the best way to get in shape for the apocalypse, what is? What kind of athlete would survive the longest in the ashes of society?

The answer, I think, is rather obvious. Life in the wasteland is more a marathon than a sprint, so naturally, it is none other than the endurance athlete who would excel in the throes of nuclear conflict.

Endurance athletes compete in sports that test their ability to keep going, or endure. Their goal is often to outlast their competition, a skill that will undoubtedly give them an edge post-apocalypse. Being able to run extremely long distances without stopping, something that endurance athletes are great at, would be the most useful tool in their toolbelt. Gasoline will run out eventually, and at some point in a post apocalyptic world, your survival will likely depend on your ability to get from point A to point B. No other athlete is better equipped for such tasks than the endurance athlete. Training for marathons and triathlons is a great way to ready your body for life after the fall.

Now, this isn’t all to say that you need to stop what you’re doing and start training for a marathon today. If you lift weights, keep lifting weights. But if that’s all your workout consists of, then it’s time to introduce some endurance training into your routine, because nuclear doom is as present as ever. So strap on those running shoes and step out the front door. Run like your life depended on it, because some day, it might!