How is my metabolism getting worse?

[lazarus_come_forth]

I’m a 45 year old male. Started working on fitness again 4 months ago. I started at 257 lbs, 38% body fat. I am now at 236 lbs, 33.1% body fat.

During those 4 months, I have been doing resistance training three days per week, with noticeable and measurable strength improvements. Diet is strict. I measure everything and have not had a cheat meal or day. For cardio I do 30 minute sessions four days per week. Three days at zones 1 and 2. One day at zones 3 and 4. Not a single day has been missed

At the beginning of this journey, my measured vo2max was 24.1. At zone 1, I burned 40% fat and 60% carb. Recently, we took another assessment and my vo2max is at 22.9, burning 100% carb at zone 1.

Huh?

 

[sdem2]

@lazarus_come_forth For your cardio (1) is your pace improving? (2) do you feel less tired? (3) is your resting heart rate stable or decreasing?

Vo2 is a great measure of fitness, but it's not always consistent and it's not always assessed acurately. In general, people underestimate the value of very simple metrics like the above 3. In other words, don't get hung up on what is almost certaiinly a measurement error.

 

[lazarus_come_forth]

@sdem2 Yes to all three

 

[sdem2]

@lazarus_come_forth Awesome. You're getting fitter. 20 pounds in 4 months is also great progress, particularly when you're gaining strength at the same time. Forget about the Vo2 max measurements. Keep doind what you're doing, and good luck!

 

[lazarus_come_forth]

@sdem2 Thanks for the words of encouragement. It goes against my nature to ignore data, but I acknowledge that instruments and the person overseeing them can be flawed

 

[kowalski1]

@lazarus_come_forth How exactly did you measure VO2 max? Was this done on a treadmill with a respirator, while they measured your breathing, heart rate, and oxygen consumption? Or just something like a smartwatch and/or chart? Because I can tell you right now, there really isn't a proper way to measure VO2 outside of a lab setting.

The fact that you're able to run faster and longer, means that your VO2 max likely increased, not decreased.

 

[lazarus_come_forth]

@kowalski1 A heart monitor on my forearm and mask monitoring my breath

 

[curtswill]

@lazarus_come_forth Out of curiosity, what do you estimate the reproducibility of VO2 measurements to be at?

 

[lazarus_come_forth]

@curtswill No clue

 

[curtswill]

@lazarus_come_forth And you aren’t even a bit curious to know how that might affect your assessment of your metabolism?

 

[lazarus_come_forth]

@curtswill Sure. Enlighten me

 

[curtswill]

@lazarus_come_forth Oh I don’t know what the reproducibility is. Not sure how I would know.

But if the drop in VO2 is something that concerns you I would encourage you to measure it again and see what you learn. You might find out your lungs did not suddenly get worse, for example.

 

[lazarus_come_forth]

@curtswill Sorry, I thought you knew of such data

 

[curtswill]

@lazarus_come_forth No worries. I am just trying to make a point here that there’s a limit to how much you can trust any measurement. That’s an entire scientific field

 

[lazarus_come_forth]

@curtswill Which is irritating to me, because I come from an engineering background where you calibrate instruments and can iterate tests over and over until you can find a predictable bell curve of results. The human body sucks. Whoever designed it was a clown

 

[nycgurl]

@lazarus_come_forth Did you fast before the test? Tests are very inaccurate in terms of carbs Vs fat burnt if you don't do them fasted.

 

[lazarus_come_forth]

@nycgurl I did not. They instructed me to eat as normal