I am running more than I have in the past but I’m training for relatively short distances and I have too many other sports and activities to run everyday. As I looked around for training plans I noticed that most of them recommend a heck of a lot of running. This got me wondering if there are differences in how people run based on whether they are running a lot or just a little and it turns out there are. Verheul, Clansey, and Lake (2017) compared the mechanics of the legs of low and high mileage runners. Low mileage runners were those running less than 15 km a week (I’m just over this amount at the moment), while high mileage runners were going for more than 45 km a week. The researchers compared the two groups (which did include male and female but only a handful of female runners) at different running speeds.
As both groups increased in speed they had greater muscle activation. However, between the two groups the high mileage group had lower activation of the quadricep muscles (the ones on the front of your thigh). The high mileage group also had more time in the air (ie they spent less time with at least one foot in contact with the ground) compared to the low mileage group. There were also differences in how much they bent their knee (low mileage bends it more as the foot contacts the ground and high mileage bends it more as the weight transfers onto the leg). The high mileage runners were also able to store more elastic energy in the tendons of their ankle, which the researchers hypothesize may be connected to the lower muscle activation.
The lower muscle activation and greater elastic energy both mean that high mileage runners are more efficient than those of us in the low category. As I’m unlikely to start running 45 km a week, so I’m likely to stay in the low mileage category but this does make me wonder if there are things I can do to train my muscles and tendons to achieve some of the benefits of the high mileage training.