First, let me recap the session for those of you who weren't there. The idea is to run the session close to threshold effort. Rather than run flat out up hill and jog back down, we throttle back a bit on our uphill efforts and push the pace downhill to keep the effort going. In heart rate terms, rather than see the HR rocket during the efforts and drop right down on the recoveries, it peaks a lot lower, around or just above threshold level, and drops only a little on the run back down the hill. The session then becomes more of a tempo run, but with a whole lot of hills thrown in. We still get the strength benefits of a hill session, but now we are targeting our aerobic system rather than it being a predominantly anaerobic session. As you know, I'm passionate about focussing on the most appropriate energy system to us as endurance runners. The session also has an added benefit in that it's a form of race rehearsal: in races you need to keep your effort fairly even over hills, throttling back on the speed uphill and being able to power over the crest and off downhill. Pushing hard uphill so that your legs turn to jelly and then staggering over the crest will simply mean that all the people you overtook on the way up will come screaming past you on the downhill.
Incidentally, in Lanzarote I was trained by the man who first coined the expression 'Kenyan Hills': Keith Anderson. Keith had the opportunity to go and train with the Kenyans in the Ngong hills. He saw how they ran tempo sessions over a rolling hill course, and the brought the session back to the UK. We can learn a lot from those Kenyans!
So why is running downhill seen as such a damaging thing to do? The answer lies with what's known as eccentric muscle contractions. Imagine holding a dumbell in your relaxed arm and doing a biceps curl. As you draw the dumbell up towards you, your biceps contract and shorten. This is called a concentric contraction. Now lower the dumbell in a controlled manner. As you lower, the biceps are still contracted, under tension, and doing work, but this time they are lengthening. This is called an eccentric contraction. The training effect of an eccentric contraction is greater than that of a concentric contraction, as the tiny amounts of damage done by the loading, which give the training effect, are greater under eccentric loading than concentric loading. For this reason it is important that you should always lower the dumbell in a controlled fashion, during the eccentric phase, as this is where the most training benefit is. This concept should be familiar to those of you who weight-train.
So now let's look at what happens when you run downhill. As your foot hits the ground in front of you, it has dropped further than usual and your momentum going into the foot strike is a lot greater. Your leg then flexes to absorb the shock of the landing and much of this is taken by the quads as they lengthen to absorb the impact. In other words your quads are under eccentric loading - they are being worked hard and potentially could be left quite sore by a heavy session of this.
Let me give you a couple of examples of the damage potential of downhill running, both from the granddaddy of the downhill: the Boston Marathon. The course is characterised by an opening 3 or 4 miles of continuous downhill that will pound away at the legs of the unwary. At around the 20 mile mark we then have a series of hills culminating in Heartbreak Hill followed by a mile of continuous downhill before the flat run into Boston. In 1982 Grete Waitz had been running on world record pace, helped no doubt by the opening downhill miles, before cresting Heartbreak Hill with a big lead. With just 5 miles to go she retired at the bottom of the hill, the pain in her legs being too great to continue.
My experience of Boston was that I'd trained and trained for downhill running, learning the correct technique, having been advised by a former London Marathon winner Mike Gratton. On the day though I wasn't able to execute the plan, for reasons I'll explain shortly, resulting in pain in my knees by half way. The descent of Heartbreak Hill was excruciating - despite the steep hill I was no faster downhill than I was on the flat, such was the pain with every downhill stride. I finished the marathon is a respectable 3:31, but 2 days later I was barely able to walk. My legs buckled as I was handed my cases at Heathrow and the other passengers had to help me to my feet, the destruction of my quads now being complete.
All is not lost though. With correct technique we can avoid such problems. This is why I was careful on Thursday to talk about the proper technique for downhill running.
The key to comfortable downhill running is to avoid the eccentric loading of our quads as much as possible. This is done 2 ways:
- Lean forward down the hill - this reduces the amount of extra height we get with each step and reduces the impact of each stride.
- Avoid heel striking - it is natural when running downhill to dig your heels in to slow you down, but it is this that causes all the pounding and eccentric loading. You need to be as light on your feet as possible and try to land more on your forefoot. Natural forefoot runners have an advantage in this respect, but we should all try to achieve this.
We can achieve a smooth light gait by another couple of techniques:
- Relax! Play the rag doll and keep your upper body really loose. If you tense you will start to dig your heels in.
- Let gravity take over. Pick up your cadence and let the hill do the work. (This is pretty much the same point as above.)
- Consciously lift your heels behind you, more than you normally would. This will help you land more on your forefoot, and will help lengthen your stride downhill without digging your heels in. It will also help with the gravity assisted increase of pace.
There will come a time when the hill is too steep to be able to do the above and the heels start to dig. On the road, these hills tend to have road signs warning motorists of the gradient, and we don't tend to encounter them too often. Farlington Avenue in Portsmouth is just about at the limit of where I can comfortably employ this technique. The Boston Marathon certainly has nothing anywhere near this gradient, so is eminently suitable for this.
At steeper gradients there is a different, 'Gazelle', technique used by fell runners, but this requires a lobotomy, and besides is really a racing technique rather than something designed to preserve your quads. Having said that, I do find it more comfortable to employ the 'Gazelle' technique on steep off road than try to hobble down slowly, but the ankle-turning potential is great. Maybe I'll describe it in a later article.
So having described the technique, and told of how I practised it meticulously in preparation for Boston, why did Boston go so wrong? Two things conspired against me at the start:
- The crowds - we were packed into the pens like sardines, and although we were running smoothly from the gun, there wasn't room to get comfortable and relaxed.
- My natural pace, resulting in a finish time of 3:31, was far greater than my qualifying time of 3:47 would indicate, so I was in a pen with slower runners.
So the gun went and for the first 3 miles I had to keep my pace in check, unable to run freely. I was digging in my heels, trying to slow down to avoid bumping into people, and it all went wrong from there. My pace was conservative from the gun, but unlike other marathons where this would have been a virtue, it actually helped to tire my quads. If I'd been able to relax and let my pace flow, my quads would have been in far better shape by the end.
So next time you are out for a run and encounter a downhill, try practising the technique. You don't have to wait until the next hill session. Your quads (and knees and everything else connected to them) will thank you for it!
