The time period being referred to is the sensitive period. This time period is also referred to as the critical period. The importance of a critical period is such that it must involve certain stimuli from which an organisms learns and acquires traits. If some of these stimuli are not present in the critical period, the organism has difficulty acquiring the trait or skill, and may even find it to be impossible to learn the skill.
<span>The blood pressure measured in the calf is lower than it is in the arm. Blood pressure in the body is highest right at the ascending arch of the aorta. From that point, the pressure decreases as blood moves "distally" from the heart. Purely mechanically, legs are farther away from the heart than are the arms, thus pressure is less.</span>
As you workout your heart rate will increase because you need oxygen.