Brooks Fahey Baldwin said:The most interesting part about Froome is the insanely low heart rate at threshold and of course the fact that the his heart rate doesnt increase with an attack.
- Cardiac ouput follows oxygen consumption very closely during exercise.
Therefore, what the hell is going on with his cardiac output at maximal efforts?
Its as if he never reaches VO2 max while pedalling. The lack of a rise in HR while power increases also points to an increadible anaerobic threshold. So what can make that sort of thing happen?
Apparently Froome has a MHR of 170. This is consistent with his rides up the Ventoux and Puerto de San Lorenzo where you see him pushing hard with a heart rate of 152-160 equivalent to 90-95% MHR. Other top cyclists have also reported having a relatively low MHR. You're right that cardiac output does follow oxygen consumption, but oxygen consumption doesn't equal power output over a short term attack. What you see is his heart rate increasing after the attack, which is what you'd expect from an anaerobic effort to product 600+W. The fact that he can manage and sustain 90-95% MHR after such an exertion is, like you say, indicative of a very high lactate threshold. As to what makes that happen, training combined with a decent physiology.