Cardiac Fitness Score

[PHS273]

When I started to wear Fitbit my cardiac score showed 49-54 in Feb 2021 after 3 months 

when I started to run it showed 38 and now after 15 days it showed 40 so why it decreased first and now slowly increased.

[PHS273]

how to improve my cardiac fitness score ,currently it is 40, my age is 52 sex male wt 68 Kg Ht 165 cms

I walk daily 13000 steps do bilking for 45 minutes and running for 15 minutes

what else to be done to improve lung capicity

[Heybales · Accepted solution]

It's a rough estimate based on figures that if missing are also estimates - making a rougher estimate.

Likely when you started running more figures provided so better estimate - which was lower.

Initial figures were bad. No way VO2max would be that high just starting. 40 still sounds high for VO2max after a short time.

VO2max is actually mostly not the lung capacity - the ability of the lungs to take in enough oxygen usually far surpasses what the body can use.

You also have improvement in red blood cells, but mainly the mitochondria in the cells using the oxygen and supplying energy - that just takes time to improve/increase those.

Advice is to keep it up.

The running stat's play a bigger picture in that estimated VO2max.