Downhill Running
Many running plans include some ‘hill training’, which generally consists of either running a hilly course, or running hard uphill to build strength, aerobic and anaerobic capacity. While these techniques can be useful, they do not focus on the most important part of the hill – the downhill. While the uphill may seem to be the difficult part of the hill, for endurance runners the greatest benefit comes from the downhill. When running uphill, a runner can reduce pace so that the effort is close to the effort on the flat. The impact on the muscles and joints is generally lower when going uphill than on the flat as the flight phase of the running stride has less decent than ascent.
Downhill running is tough for several reasons, but the main one is that downhill running does more muscle damage. This damage causes immediate weakness in the muscles, as well as soreness in a day or two. (See Delayed Onset Muscle Soreness for more details.) If you’ve ever run a long steep descent and felt that your legs are numb or shaky, you’ve experienced this damage. The good news is that the more downhill running you do, the more you muscles adapt to be able to handle the load. An approach for downhill training is documented at Downhill Intervals.
Running efficiently downhill can make a significant difference to race performance. Running hard up the hills and recovering on the downhill makes for slower race times. An increase in intensity will make a small difference to the uphill pace, but it can make a large difference to the downhill pace. I suspect that downhill training also helps with flat races. All running involves some of the stresses that cause Delayed Onset Muscle Soreness, and having resistance to this damage can keep you strong through to the end of the race.
I consider downhill running one of my Running Breakthroughs