The SRM TRaining system with FSA carbon cranks on my bike

The Garmin Edge 705 integrates perfectly with the SRM Training System


SRM measuring power on the climb of the Haelakala cater yesterday

Altitude profile on the Garmin Edge 705

SRM
Whilst a runner or a swimmer can measure performance quite accurately by simply measuring time with a stopwatch, time or speed are not good indicators of performance in cycling. These measures are subject to variability due to wind, slope, and air density. The only appropriate performance indicator on the bike is power. Before SRM developed its first powermeter it was only possible to measure power in a laboratory. Recently however, power measurement for cyclists have become affordable and practical.

In a paper I wrote back in 1998 (1), I discussed the role of power versus heart rate. Each of these measurements has its own advantages and disadvantages. Power is the true measurement of performance and heart rate gives an indication of your bodies effort to achieve this power. The power and heart rate relationship does not only change with the terrain, it also changes over time and with changing environmental conditions. For example, if you would be riding at the same power output for several hours, your heart rate would show a drift upwards. If you would be riding in warmer conditions, your heart rate is higher for the same power output. Speed, another indicator often used by cyclists, is only useful when the terrain does not change. Of course speed and power relationship changes completely when riding uphill or downhill.

So if you want to monitor your performance over time and want to see if you are improving power really is the only valid indicator. I have written about power and how it can be used in a chapter in my High Performance Cycling book. Very soon I will write a section on power on this web site, giving examples from my recent rides, explaining how a power meter can be used.

SRM and Garmin
With the launch of SRM's new PowerControl VI earlier in the year, all PowerMeters are now available in wireless versions and with different types of cranks. In my opinion going wireless is a HUGE improvement of a highly accurate and great training tool! The cranks I am using are the carbon FSA cranks and I have to say that I am extremely happy with them. They have not let me down once since I have them.

Another great feature is that SRM interfaces now with Garmin. The Garmin Edge 705 uses ANT +Sport technology which allows it to interface wirelessly with a heart rate monitor, cadence sensor but also the SRM Training system!

So now in one cycle computer it is possible to have information on power, speed, cadence, heart rate, altitude, gradient, etc... virtuyally everything you can think off. After the trauning session you simply connect the Edge 705 through a USB cable with your PC and all the data is immediately downloaded. There are various software packages to collect and analyse the data. I prefer to use TrainingPeaks as this is, in my opinion, the best integration of all the information and allows in depth analysis.

Click here for a screenshot of TrainingPeaks fileviewer (one of the many options in TrainingPeaks). This is my first ride in Maui, an out and back ride towards the Volcano.

1. Jeukendrup, A. E. and A. van Diemen. Heart rate during training and competition - cycling  Journal of Sports Sciences 16: S91-S99, 1998.