The SA Node is the heart's normal pacemaker. When the SA Node depolarizes, electrical signal spreads through the atrial muscle causing contraction.
Explanation:
Inherent rhythmicity / automaticity - The property of the pacemaker cells of the heart to start electrical sequence of depolarization and repolarization.
SA Node or Sino-atrial Node generates the electrical signal.
The electrical signal passes through internodal pathways, atrial fibres, atrioventricular node (AV Node), the bundle of His, Purkinje fibres, right bundle branch, left bundle branch.
Systole - Contraction of cells when the electrical signal of depolarization reaches the contractile cells.
Diastole - Relaxation of cells when the electrical signal of repolarization reaches the myocardial cells.
Well naturally the only thing here that is impossible for you to do, is change your hereditary.
All the other choices are good options to promote cardiovascular health.
It leaves less of a risk of obesity
B) exercise-associated muscle cramps
1,3,4,6..........those are your answers