DOWNHILL RUNNING SERIES: WHY DOES RUNNING DOWNHILL HURT SO MUCH?
~ By Annie Bothma, February 2023
In my last few posts, I talked about how to conquer the climb. I explained the benefits of uphill running for runners, gave my top 10 tips for becoming a better uphill runner, and provided some of the best uphill workouts for runners can do to get fitter and stronger.
But, what goes up must come down!
What happens after you reached the top and it is time to go back down?
Most runners look forward to running downhill, but why does running downhill hurt so much? How can you become a more efficient downhill runner? And, how do you prepare for a race that has a lot of downhills?
In this next series, I will tackle the other side of the hill: THE DOWNHILL.
WHY DOES RUNNING DOWNHILL HURT SO MUCH?
Often runners just think about the climbs they may encounter in a race or their next training run, but forget about the downhill running sections of the running route that may provide an even bigger challenge for some!
Running downhill is a lot more impact on your body than running on flat surfaces or running up a hill. Runners often complain that their legs feel like lead after they have done a lot of downhill running. The biggest reason downhill running leads to more muscle soreness is due to an increase in muscular damage and neuromuscular fatigue.
The later, is responsible for acute, as well as prolonged, impairment of muscle function, classified as central fatigue (originating in the central nervous system), or peripheral fatigue (distal to the neuromuscular junction).
DELAYED ONSET MUSCLE SORENESS
Running downhill creates excessive muscle damage, primary as a result of many, heavy eccentric contractions when running downhill. Due to these eccentric contractions downhill running adds a lot more work to quadriceps and calf muscles.
As your run downhill, the quad muscles in your legs simultaneously activate and lengthen to absorb the shock of running downhill and gradually lowering your center of mass. This active lengthening of muscle fibers is paradoxically termed an "eccentric contraction". This is the primary, but not the only, reason the excessive for muscular damage caused by downhill running. Eventually, this damage compounds over time and causes runners to feel like they have legs made of lead later in a race.
This is the primary reason why you struggle to get out of a chair the next day after doing a significant amount of downhill running! This post-run pain is referred to Delayed Onset Muscle Soreness (DOMS) and is caused tiny, microscopic tears in your muscle fibers. Your body responds to this damage by increasing inflammation, which may lead to a delayed onset of soreness in your muscles.
RISK VS. REWARD
RISKS OF HARD DOWNHILL RUNNING
If you are preparing for a race with a lot of downhill sections and plan to include hard, fast downhill running as part of your training, it is important to understand and consider the following factors:
Increased recovery time due to the effort. You will need at least 2-3 days of easy running after a hard downhill effort. Before you plan a hard downhill session, make sure doing so doesn’t compromise your overall training volume.
Increased risk of injury, either due to the excessive pounding or acute injury from a fall.
Increased muscle soreness and inflammation.
REWARDS OF RUNNING DOWNHILL
It is not all bad, you can still enjoy the downhill after a hard climb. Incorporating downhill running gradually and carefully in training can even be very useful. Not only does helps to improve your speed, but also improves our ability to handle intensity of the workouts.
Eccentric forces involved with downhill running improves quadricep strength.
Downhill runs are typically done at a faster pace than flat or uphill running and may therefore improve your neuromuscular co-ordination and speed in general.
Downhill running can help you adapt to training stress, and make you more resilient against DOMS.
I love the free act of running downhill and feeling like I am flying! However, I coach a lot of runners who are scared of the increased muscle soreness that can occur with running downhill. I acknowledge that some runners are afraid of getting injured as a result of downhill running and some may struggle to maintain good form while running down a hill.
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