Training for the Downhills: How to avoid the dreaded quad blowout

Trail runner contemplates whether or not he trained enough for his impending downhill run...

Years ago, my brother signed up for a Half Marathon class as his health elective in college. Since he hadn’t considered himself “a runner” and mostly only ran for soccer, he decided to sign up for the “easiest” Half Marathon he could find – a net downhill point-to-point road race from Fort Mountain State Park to downtown Chatsworth, GA. This race drops over 2,000 feet with almost all of the elevation loss being in a 7-mile section in the back half of the race. The race boasts that these miles with 5-10% downhill grades will drop your pace by 40-80 seconds per mile, enticing anyone looking for a USATF-certified personal best. I was so excited to cheer him on, but also quite surprised to see so much carnage and pain at the finish line. While most people love a short downhill to the finish, I remember my brother saying the flat section in the final mile felt like merciful relief to his legs after the brutal sustained downhill miles. Why was this race so hard on the body? 

If you are training for a race with a lot of elevation loss or steep downhills, read on to learn how you can best prepare for the quad-shredding.

Why do downhills hurt?

Downhill running seems like it could be friendly. Gravity is helping us with our forward progress, so shouldn’t that make running easier? Yes and no. 

Downhill running can allow us to achieve faster paces since gravity is helping pull us along, but your body experiences a lot of biomechanical strain as a result. Even if you run at the same pace on downhill versus flat terrain, your muscles undergo more damage running downhill due to the volume of eccentric muscle contractions that occur. Eccentrically loading the muscle means that it’s activating while lengthening; as compared with a concentric muscle contraction in which the muscle is activating while shortening. For example, when thinking about a bicep curl with a dumbbell – the concentric phase is when the bicep is shortening as you bend your elbow to lift the weight; the eccentric phase is when the bicep is lengthening as you lower the weight back down in a controlled manner. Eccentric muscle contractions cause more muscle damage than concentric contractions. Generally speaking, this isn’t a bad thing because the process of breaking down muscle stimulates muscle building, and eccentric loading also has a uniquely positive impact on tendon strength. However, excessive eccentric loading without sufficient training preparation or adequate recovery can increase injury risk. 

It’s also important to note that your muscles experience eccentric loading at different points in the gait cycle with running on any grade (uphill, flat, and downhill), but that absorbing the forces applied to the body with downhill running just leads to MORE eccentric loading than flat or uphill running. As a result, your body experiences reductions in running economy immediately after and for several days following a bout of extended downhill running. Running economy is a term used to describe your body’s oxygen consumption at a given speed. In other words, improved running economy means your body does not have to work as hard to sustain a certain speed, or on the other hand, reduced running economy indicates that your body is having to work harder to sustain a certain speed. What this means in practice is that after a long downhill segment, your body is less efficient at running, even on level terrain. Additionally, we see markers of muscle breakdown in the bloodstream for several days after extended downhill running that contribute to delayed onset muscle soreness (DOMS) and neuromuscular fatigue in the form of loss of peak muscle output. 

Many of these changes can last 4-5 days, meaning it’s normal to see some performance reductions for subsequent runs after sustained downhill efforts. The good news is that specific training can lead to reduced soreness and faster recovery of muscle performance following downhill sessions along with potentially less reduction in running economy and therefore less impact to overall running performance immediately after and in the following days.

How to best prepare for downhills: Repeated Bout Effect

One of the best ways to prevent performance decrements and reduce soreness from downhill running is known as the “repeated bout effect.” This well-researched phenomenon demonstrates that previous exposure to a downhill running session results in less muscle damage during the second bout of downhill running, even when the sessions are up to 9 weeks apart. Some evidence supports that better results are seen in the second bout when greater muscle damage occurred in the first bout. 

My training recommendations for the Repeated Bout Effect:

1. Plan to include 2-3 downhill running sessions in your training plan before your race in order to appropriately build up your resilience to downhill running. Although higher levels of muscle damage in the first bout lead to better tolerance to the second bout, I wouldn’t suggest going all-out on your steepest local downhill right away. We don’t want one aggressive downhill session to result in injury and risk your race! 

2. Consider your race conditions and plan for your final downhill session to be as steep or just a tad steeper than your race. If you’re new to sustained downhill efforts, then schedule 3 downhill workouts before race day so you can gradually increase the time and grade on each workout to mitigate injury risk.

3. Space out your downhill sessions by 2-3 weeks. This allows your body plenty of time to recover from the previous downhill session and go into your next downhill workout feeling strong.

4. Aim for a total duration of 30 minutes of downhill running. There aren’t many places around Atlanta where one can find a 30-minute segment of downhill terrain unless you have a treadmill that can simulate downhill running. The good news is that some researchers varied their protocols to include 6x5-minute downhill repeats or 5x8-minute repeats and found similar results as those who performed 30 and 40-minute sustained sessions.

What if I don’t have access to hills?

For the flat-landers in the audience, there is some evidence to suggest that other eccentric-focused exercises such as plyometrics can provide increased tolerance to downhill running. Additionally, one study found that “isometric preconditioning” can provide similar but shorter-term protective effects as prior downhill running. In this study, just 10 repetitions of maximal isometric holds two to four days before maximal effort eccentric loading resulted in less muscle damage. In practice, the muscle groups to prioritize these isometrics should include quadriceps, glutes, and calves. I suggest trying 10 repetitions with 5-second holds of weighted squats, single-leg glute bridges, and weighted calf raises off a step. While this less-specific method is not as effective as prior downhill running, it can still help prime your tendons and neuromuscular system for eccentric loading on race day. 

Regardless of your access to hills, we encourage all runners to include strength training in your exercise routine to reduce injury risk and promote longevity in the sport. To learn more about our recommendations on strength training for runners, see this blog post from Dr. Elizabeth!

For more specific injury-prevention and training advice tailored to YOU, come see us in our Atlanta or Serenbe offices! Give us a call at 404-343-3314 or email us at admin@precisionpt.org to get scheduled.

See you out there!

Cheers,

Dr. Perrin Clavijo, PT, DPT

Precision Performance & Physical Therapy in Atlanta and Serenbe