be lower than 60 per cent. In my own laboratory weve measured heart rates at the lactate threshold ranging between 140 and 185 in a group of male athletes in their 20s; this ranged from 70 per cent to 90 per cent of their MHR. I suspect that the reason
for someone in their 40s, because maximum heart rate declines as we get older. The rough rule of thumb for estimating your age-predicted maximum heart rate is to subtract 0.8 times your age from 214 for men, or subtract 0.9 times your age from 209 for women
