What’s more, a 2021 paper published in the journal Science found that, on average, metabolic rate dropped by about 0.7% a year starting after 60. Harvard points out that that’s a lot later ...

Understanding Basal Metabolic Rate (BMR) ... To estimate your metabolic age, compare your BMR to average BMR values for people your age using metabolic age charts.

This is due to children's smaller lung size and higher metabolic rate. That said, what's considered a "normal" respiratory rate for adults can continue to increase or decrease as we age, Dr ...