Worth your weight?

I am currently miles away from race weight.  In fact I am nearly 10kg heavier than I was for World triathlon champs 2 years ago.  The question however is whether it is worth the hard work and dedication in order to get back to peak race weight?

Before World Championships in 2015 I was in great shape!  I have added a few kilos since!

Well the simple way is to undertake some basic calculations, and look at the potential impact that weight can have on performance.  So, as an example, I recently ran a half marathon in Jersey.  I was more than happy with my performance of 1:24:19.  In fact this is probably the fastest half marathon I have run in nearly 10 years.  But could (or should) I have gone faster?

Using the calculators from “Running from Fitness” inputting my race time, and at the age of 46 I have a predicted (relative) VO2max of 55.0 ml/kg/min.  [Remember that VO2max (relative to bodyweight) is considered to be one of the best indicators of cardiovascular fitness – but it is not the sole indicator of performance, as I highlight in a previous blog.]

Assuming my weight on race day in Jersey was 78.5 kg, my absolute VO2max (that is the TOTAL amount of oxygen your body can take up and use every minute, but not related to body size) is predicted at 4.3175L/min.

Relative VO2max (L/min) = Absolute VO2max/body mass (x1000) (ml/Kg/min)

 Essentially if I lost the weight sensibly, and didn’t lose any muscle mass, and so my peak capability wasn’t compromised, this absolute value should not fall.

Rather than guessing your “optimal weight” we can assess it for you.  (As Dr Palmer is doing here for footballer Matt Murray)

So assuming I can drop my weight to 72kg (2.5 kg higher than where I was at Worlds, but a value that would be more than sustainable for myself), my relative oxygen uptake would rise by over 9% to 59.965 ml/Kg/min! That’s without doing any additional training!!!

Now, assuming nothing else changes (running economy, energy storage, heat tolerance etc), plugging this new VO2max into the Running for Fitness calculators, the projected time for my half marathon would be an impressive 1:18:12

A massive (potential) performance gain of over 6 minutes!!!!

…..now in my mind, the performance enhancements could be even greater, as the course in Jersey started with a gentle climb of over 7km, so the energy saved on the climb with a lower body weight would be even greater.  In addition, reducing bodyweight can also increase heat dissipation and therefore increase performances further.    ….and of course to achieve the lighter body weight I would probably be training more and fitter!!!!

So, looks likes it is time for me to get back on the diet!!!!


Hope this gives you something to think about, and if needed as a part of your Sportstest this is something that I can work through with you.  We can also work through the dietary interventions needed to help you achieve optimal performance weight.

Hope this helps