|Flower path on the way to the hill|
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|
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.