29 April 2014

The benefit of running short uphill repeats

It has been summer temperatures in the high 60’s (around 20 degrees Celsius) in Uppsala the past week and it feels a little like the spring just rushed by so I am almost looking forward (or not) to the snow which is expected here on Thursday.

Flower path on the way to the hill
The past week was absolutely great also from a running perspective – I focused on short hill repeats to build both muscle strength, aerobic capacity and to improve my so called energy cost of running. I believe it is really a good training form to improve all three of these factors. I ran a total of five short hill repeat trainings during the week each training lasting between 30-60 minutes with varying number of repeats of 1-2 minutes. My total vertical gain during the week was around 3000 meters (9850 feet), almost ridiculously little considering the D+ of over 28,000 meters (92000 feet), approximately ten times as much, waiting at Petite Trotte à Léon (PTL). However, I think that even short hill repeats are really beneficial. The science is a little bit ambiguous regarding the extent of the benefit, however, but as it really is a fun exercise and something I think directly applicable to the practice of running in mountains. Jill Homer just posted a very inspiring text about the fun of practicing bike riding and I guess I think the practice of running uphill as really fun, despite thepain when being close to or just over the lactate threshold.  

Regarding the evidence for the benefit of hill repeats I just read a great PhD graduate thesis entitled “Strategies to improve running economy in trained distance runners” written earlier this year by Kyle Barnes at Sports Performance Research Institute New Zealand at Auckland University of Technology (freely available at http://hdl.handle.net/10292/7125). In his thesis and an associated publication, Barnes demonstrate that already well-trained athletes can improve their running economy substantially with 2-6% through acute and chronic bouts of movement-specific resistance exercise performed by short duration near-maximal uphill sprints (Barnes et al “Effects of different uphill interval-training programs on running economy and performance” Int J Sports Physiol Perform. 2013; 8:639-47). In the study they let twenty well-trained runners (average 5-km race personal best time of 16.5 ± 1.2 min and average weekly training volume of 95 ± 25 km) perform aerobic and biomechanical test before and after a 6-week training period during which they were assigned to one of five uphill interval training programs (see figure below).

From Barnes et al 2014.
 
There were no clear optimum for time-trial performance (see figure below), but Barnes and colleagues conclude that runners can assume that any form of high-intensity uphill interval training will benefit 5-km time-trial performance. The results from Barnes are confirmed by recent findings by Ferley and colleagues of well-trained runners undergoing a 6-week treadmill training program, but they also find that normal interval training on flat surface leads to the same improvements (Ferley et al “The effects of incline and level-grade high-intensity interval treadmill training on running economy and muscle power in well-trained distance runners” J Strength Cond Res. 2014; 28:1298-309; and Ferley et al “The effects of uphill vs. level-grade high-intensity interval training on VO2max, Vmax, V(LT), and Tmax in well-trained distance runners” J Strength Cond Res. 2013; 27: 1549-59).

From Barnes et al 2014
There are no similar studies of hill repeats in mountain ultramarathon runners specifically, but I think the results would be even clearer and more directly applicable to the race situation. An interesting study of a runner wearing a portable metabolic unit during the first 64.5 km of Western States Endurance Run 100 not surprisingly reveals higher energy expenditure while running a trail in mountain terrain compared to energy requirements required by this individual when running in nonundulating terrain (Dumke et al “Indirect calorimetry during ultradistance running: A case report” J Sport Sci Med 2006; 5: 692-698). It has been hypothesized in  recent Norvegian study by Losnegard and colleagues that the optimal exercise economy can be achieved in an exercise mode where the athletes are highly skilled and that uphill running, compared to cross-country skiing, is good for this as the technical requirements is lower (Losnegard et al “Exercise economy in skiing and running” Front Physiol 2014; 5: 1-6). I think this is only partly true as in particular during some ultramarathons trails there will be some clear technical challenges that might improve running economy and it is important to practice this specifically – for instance running with poles can be a challenge from a technical standpoint if not tested before. Losnegard’s study was also conducted on a treadmill. Indeed, I have in a previous post discussed the findings by Vernillo and colleagues that runners of Tor des Géants during the race modified their uphill-running patterns for a more economical mechanics and lower energy cost of running uphill specifically (Vernillo et al "Influence of the world's most challenging mountain ultra-marathon on energy cost and running mechanics" Eur J Physiol 2014; 114: 929-939).

In summary, practicing short uphill repeats appear to be beneficial for running mechanics and decreases the energy cost of running, but more studies are needed to investigate if and how much they specifically can improve longer mountain ultramarathon performance.

2 comments:

  1. Great information. I assume that the hill repeats last between 30-60 seconds, not the 30-60 minutes stated in the second paragraph.

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