For many runners, keeping track of how far and how long they have run has been all the data they needed to know. Both could be done with most modern sports watches, including the new Apple Watch Series 2, which finally includes GPS to follow your route.
But as runners have tested the limits of their sport, with sports scientists bringing us enticingly close to a two-hour marathon time, more metrics are needed. The more you measure, the more you can improve your runs.
I have been trying out a couple of devices so small that you can soon forget they are there, but which can provide fantastic guidance on foot strike, cadence (steps per minute), pace and stride length. They are the Lumo Run, a $99 sensor that clips to the back of your shorts, and the MilestonePod, a $25 disc that you add to your trainer laces.
The Lumo, which was designed in collaboration with sports scientists at Loughborough University, tracks cadence, bounce, pelvic rotation and pelvic drop. When connected to a free smartphone app, it then prescribes corrective exercises to improve your running performance and efficiency. I was told to do high knee and toe tap exercises to increase my cadence above 180 steps per minute.
The Milestone measures cadence but adds such things as contact, which is a measure of the average amount of time your foot stays on the ground — something runners want to decrease — and which part of your foot strikes the ground, so you can work on reducing impact and spare your knees.
The latest research on running suggests that the most efficient runners use a very high cadence, as prescribed in the Pose Method developed by a Russian track coach named Nicholas Romanov.
But without a coach to assess your running style by watching you in action, it can be tricky to determine cadence and stride length on your own; these new devices make gait analysis available to everyone at a reasonable cost.
Another tool is the power meter, originally developed for cyclists. It measures how much work you are doing when you run, and at what speed. One example of these cutting-edge devices is the $199 Stryd.
As explained by Jim Vance, a former US track coach and author of Run With Power, there are three planes in running — horizontal, vertical and lateral. The horizontal plane moves you forward, the vertical plane enables your foot to leave the ground and the lateral plane is your hips and arms moving out from the body. Using a power meter, runners can decrease vertical and lateral power for a given pace and measure an increase in power in watts over a race distance.
“When you make changes to your running form, if you can see an increase in your horizontal power while at the same time you see decreases in vertical and lateral power, then you know you’ve made some very effective technical changes that should make you faster,” Mr Vance says.