## Understanding Power to Weight

April 10, 2016 |

In the above video, Stages Power Education Specialist Benjamin Sharp explains why Power-To-Weight is integral to cycling performance. It’s one of the most important factors when it comes to your fitness compared to your competition (specifically your competition’s FTP).

Why does Power-To-Weight matter so much? Well, whenever the road tilts up, gravity is the major force that must be overcome.  With a Stages Power meter, it’s quite simple to determine your power-to-weight ratio.  The easiest way to determine power-to-weight ratio for a given time period is to measure your output (in watts) for that time period (e.g. FTP) and divide it by our body weight (in Kg.) to get Watts per Kilo or W/Kg.

Let’s take a look at two real world examples.

Pat: Power at FTP = 345W.  Body mass = 81.4 Kg.  345W ÷ 81.4Kg = 4.2 W/Kg

Andy: Power at FTP = 320W.  Body mass = 69.5Kg.  320W ÷ 69.5  = 4.6 W/Kg

This shows that Andy is actually producing more power at his bodyweight at FTP than Pat.

To show how this plays out, we’ll do a couple workouts.  The first effort will be on a flat road where Pat has an advantage because he is putting out more absolute power. However, for the second exercise we’ll head to the hills. As the road pitches up Andy will be at an advantage.  With the added effect of gravity,  Andy is actually the one putting our more power per his body weight and will climb faster than Pat at FTP.

If you want to figure out your W/K at FTP, here’s Benjamin Sharp’s tips on how to FTP test.