Changes

First wild assumption is that [[Jack Daniels Running Formula]] [[VDOT ]] is close enough to [[VO2max |V̇O₂max]] to be useful. [[VO2max |V̇O₂max]] is how much oxygen you can use per minute per Kg of body weight. The second wild assumption is that you can lose body fat without losing any muscle.

If [[VDOT/VO2max ]] is how much oxygen you use per Kg body weight, then you can multiply [[VDOT/VO2max ]] by body weight to work out the total max oxygen use. If you lose body fat only, then the total max oxygen should stay the same. You can then divide the total max oxygen use by the new body weight to get a new [[VDOT/VO2max]].

Let's work an example with a hypothetical runner who completes a marathon in 3:10 and weighs 220 Lb. A marathon time of 3:10 is a [[VDOT ]] value of 50, which we will assume is also a [[VO2max |V̇O₂max]] of 50. A [[VO2max |V̇O₂max]] of 50 means you consume 50 ml of oxygen per Kg of body weight per minute. If you weigh 220 Lb, which is 100 Kg, and your [[VO2max |V̇O₂max]] is 50, that equates a total Oxygen consumption of 5000 (ml/min). Reversing the equation above, 200 Lb is 91 Kg and 5000 / 91 is a VO2max of 55. A [[VDOT ]] of 55 equates to a marathon time of 2:56. That's a reduction of 14 minutes in marathon time. There is an online calculator to make The [[VDOT Calculator]] will work out this simpler at [http://www.runningforfitness.org/calc/weighteffectfor you.php http://www.runningforfitness.org/calc/weighteffect.php]

It is very hard to lose weight, and it is even harder to lose weight without losing muscle. I suspect that this is a bigger problem than any issues of [[VDOT]]/[[VO2max |V̇O₂max]] correlation. On the other hand, my personal experience is that losing weight does give a significant boost in performance.