Recently I underwent a sub max (but only just) VO2 test. The modern day equivalent to a Douglas bag was used which was hooked up to a computer which analyzed the O2 and CO2 that I was exhaling.
On completion of the test I was told that when my heart rate went above 135BPM (beats per minute) the amount of fat that I was burning dropped off sharply; when I saw the graph it showed that the amount of fat being burnt at 140BPM was about a third of that being burned at 130BPM!!
I asked the tester how the programme determined this and he told me that the Weir equation was used to calculate the amount of fat being used.
The reason behind me taking the test is that the company that has developed this software wants to come into our gym and charge our members for this test, our members will then be told what their optimal fat burning heart rate is.
So the question is this,- How accurate is the Weir equation in determining fat kcal’s being used? I must admit that I like many on this forum tend to look at fat loss as Kcal’s in < kcal’s out. I’m sure that I don’t need to spell this out but the way I see this is Kcal’s in is what you put in your mouth and kcal’s out is increasing metabolism through an increase in muscle in conjunction with cardio work, preferably interval training which I believe is more muscle sparing.
If this test is legitimate then part of me is looking forward to ticking over at a 130BPM heart rate but it just doesn’t seem right to me.
Thanks in advance for your input,