Touted as easy and fast, downhill races grab the attention of runners hoping to snag a PR or qualify for Boston—itself a net-downhill course. And although downhill marathons such as the California International, St. George or the REVEL Race Series do send hundreds of runners to Hopkinton every April, they also destroy quads, and in some cases, totally derail any hopes of a speedy time.

That’s because downhill races “can really take a toll on the body due to the amount of excessive force exerted on the body,” says Ryan Bolton, founder of Bolton Endurance Sports Training and coach to 2015 Boston winner Caroline Rotich. “These forces are in excess of 50 percent greater than normal, flat running—the steeper the downhill, the greater the force.”

The quadriceps, which act like brakes to keep the body upright, take the brunt of the force. “Which is why we see people hobbling around after marathons, especially downhill ones,” says Bolton. “It’s also why walking down stairs hurts more than walking up stairs after a race.”

Downhill running is a braking—or eccentric—movement, where muscles increase tension as they lengthen. “Runners don’t often have massive eccentric contractions when running on flat terrain, so when running prolonged periods downhill, this really beats up the body and causes the delayed onset muscle soreness that everyone experiences,” Bolton explains.

The good news is that with some downhill training, runners can adapt to downhill terrain and improve their speed. “If a runner is going to do a race that has significant downhills, it’s important to add downhill running to the training plan,” Bolton says. “This will help adapt the body to the forces it will experience in the race.”

Downhill training should be progressively built into a training plan, carefully monitoring distance and speed. “Start with some shorter downhill repeats and build to incorporate a longer downhill section into a late section of a long run,” Bolton suggests. Be mindful that with gravity on your side, it is easy to overdo a downhill workout and end up too sore to run a day or two later. Have some fun and let yourself fly, but keep the total stress load low until your body adapts, gradually adding more downhills more often.

Focusing on proper posture is also helpful because it incorporates other major muscle groups such as the glutes and hamstrings. “There’s no way to get around using the quads,” Bolton says, “but not loading them is helpful.” Don’t lean back too much; keep upright and over your feet, feeling like you are leaning into the downhill. Focus on hinging freely at the ankles and hips, rolling down the hill smoothly with a minimum of braking.

Improving speed is another reason to incorporate downhill running—as intervals or as part of a long run—into a training routine. “For highly-developed athletes, I like to add some solid downhills late in runs when their legs are tired, to train the legs for high turnover while in a fatigued state,” Bolton says. “However, just like using downhills for adaptation, this needs to be approached with caution—too much, too fast, too soon can cause serious injuries.”

Originally published July 2018