This is true even when children are resting. Babies have even faster pulses. So since babies are so small it takes less time. Once I did my jumping jacks my heart beat a lot faster. My jumping jacks made my heart work harder.
Babies are smaller than kids and adults.
Their hearts can pump blood faster through their little bodies. The blood has a shorter way to go before it reaches the heart again. Adults blood has a longer way to go to reach the heart again because they have bigger bodies. Tony I see that my lungs have air turning into blood. Nzingha Children have faster pulses than Grown-up's pulses because they are younger.