28 April 2013

15000 feet uphill on a treadmill

Sitting in the airport lounge at Chicago O’Hare on my way back to Europe – I will have a couple of days of vacation in Paris before I fly back over the Atlantic for a meeting in Washington D.C. on Thursday and Friday. There will thus be a couple of more days of treadmill training before I am back on the real trails. I have despite an extremely hectic schedule been able to run for an hour every morning here – one of the advantages of going to the US is that I am waking up at 5 am every morning really ready to run – back home I am certainly not that motivated to leave the bed and prefer to run late in the evenings.

I have during the past four days climbed more than 15000 feet (4572 meters), today I managed 4000 feet (1219 meters), on the treadmill. I have no idea whether this really can be counted as corresponding to the same elevation on a real mountain? However, I am really happy with my pulse, which was steady between 140 to 150, pace and legs during these hour long runs each morning. I think these exercises gave more than if I had been running in the park along the lake outside my hotel. They can however certainly not replace real trail running. Even though I put the treadmill on the maximum slope, 15, it feels like quite flat and as the ground is not uneven there are no forces required to stabilize the body as on a real trail, and, most importantly on most treadmills you cannot run downhill.

There have been plenty of studies performed on the biomechanics and so called “energy cost of running” and “ground reaction forces “ of both uphill and downhill running. These have in general shown that at steep angles it is as straining for the body to run downhill as it is to run uphill (see for instance Gottschall & Kram 2005; Yokozawa 2007; Snyder & Farley 2011). In preparing for mountain races with alternating ascent and descent phases, it has been suggested that training on downhill running speed can improve performance the most as the downhill running speeds appear much lower than what is metabolically feasible, probably due to safety reasons and lack of coordination (Minetti et al. J Appl Physiol 2002; 93: 1039-1046).

Another more recent study by Townshend and co-workers found that running speed showed larger individual variation on downhill sections, whereas speed on the level sections was systematically influenced by the preceding gradient (Townshend et al. Med Sci Sports Exerc. 2010; 42: 160-169). Runners who varied their pace more as a function of gradient showed a more consistent level of oxygen consumption. These results suggest that optimizing time on the level sections after hills offers the greatest potential to minimize overall time when running over undulating terrain. To train this on a treadmill would be very difficult – on the other hand I think saving a couple of seconds on the level terrain after a steep uphill will not be relevant at such a long race as TDG – there you will be able to save more time on the long technical downhill sections.  

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