Running with power Day 1

 
17th November , 2015

Technology


According to Back to the Future Part 2 we should have hover cars by now. Its a great idea and if they worked well we’d all buy one. Unfortunately the reality hasn’t quite caught up with our ambition yet and if you did have one you’d probably only be able to drive it round in circles in the desert somewhere, not go down to the shops. Some top coaches have told me how much they’d like to see running with power however I’m not sure they have thought through the reality.

Day 1 and after five minutes of fiddling with my Garmin and chest strap to get the STRYD running power meter working I began to feel the will to run leave my body and the same feeling of dread I get when faced by a Garmin swim file.

That said it did work easily and I got some numbers. I am of course a lover of toys and gadgets and the opportunity to test this is too tempting to resist. I don’t hope to sell you one, I simply want to observe running power data for some time and try to understand how we might use it. My worst nightmare is for all my athletes to rush out and buy one then send me the data. I don’t want this because I don’t care unless it is somehow useful which right now it is not. Perceived effort and pace will continue to be the only ways I prescribe running and occasionally directions for cadence. Please let this be an experiment to satisfy your curiosity, save you money and time. I will try and use it for a few months and then decide if it yet has a useful role to play.

How would running with power work? I don’t see running with power working in the same way as cycling. Firstly it needs to be established if meaningful training zones can be determined using a critical power test which is not necessarily the case. Secondly, it is not clear to me if running power translates in to speed in the same way as cycling power. Thirdly, while cycling power is measured directly and is at least therefore an accurate measure of force production, running power is measured indirectly with accelerometers and therefor again I’m not clear how accurate it can be.

Where I could see potential for running power is as an insight is to a runners economy, something we normally only measure with gas analysis. How does power correlate to ACTUAL running economy, I do not know. However assuming it does then we might have a way to estimate and track improvements in running economy on a daily basis. My initial runs would suggest I’m woefully uneconomical so I will be keen to see if improvements mirror increased fitness.

Garmin have been using similar technology and have made available some metrics that are pertinent to running economy already. Cadence, vertical oscillation and ground contact time are all viewable on the running series of Garmin watches. They have not made power available yet so for the time being you will need to set it to BIKE mode to view your power. These are all actionable and understandable factors that are related to economy. As a coach I can as someone to increase there stride rate knowing this will likely increase there economy. So perhaps this is a way we can be more certain that any technique changes are effective?

POWER vs SPEED.tiff

STRYD RAMP.tiff

So day 1 I went for and easy morning run and observed what I like to think is an implausibly high Normalised power of 354 but who knows I’m over weight and out of shape. You can see that data on Training Peaks here. I was also wearing full winter kit and a ski jacket if that with effect power I don’t know.

I just did my planned easy run but I did briefly play with my cadence and indeed could manipulate the power, UP with a low cadence and more bounce and DOWN with high turnover. This is between 2-2.5k during a flat section on the file. I also spiked it running faster to avoid traffic on a narrow lane. So it sort of made sense.

For my lunch session I did a quick ramp on the treadmill and was surprised to find a good correlation between power and speed. It was not as linear as heart rate but I did not expect it to be. It was more a biphasic curve and looking at the apparent vertical oscillations visible in the altitude gain this might explain that but I’m speculating. I did anticipate a sub threshold ‘sweet spot’ so this might be real. I’d say my threshold is 16kph just now, way below where I want to be by the end of the winter obviously and way below the require 17.5kph for a 72 half marathon. You can see that data on Training Peaks here.

Does this tell me anything about my running economy, how to train or at what speed? I really don’t know yet I need to think about it. I will aim to keep using the system and see what happens over the coming months. What I do know is I need to train more, get faster and loose weight. I didn’t need a watch to tell me that.