Short-term Effects of Exercise

Short-term Effects of Exercise

Increased Heart Rate

  • Strenuous physical activity leads to an increased heart rate as the heart pumps harder to increase blood supply to the working muscles.
  • The increase in heart rate during exercise is to cater for the demand of oxygen and nutrients, as well as to flush out waste products such as carbon dioxide and lactic acid.

Enhanced Ventilation

  • Exercise increases the ventilation rate due to an increase in the demand for oxygen.
  • This higher oxygen demand is met through faster and deeper breaths to facilitate a higher rate of oxygen-carbon dioxide exchange in the lungs.

Rise in Body Temperature

  • During exercise, the body’s internal temperature rises due to the excess heat produced by muscle activity.
  • Sweat production increases as a cooling mechanism to regulate body temperature.

Changes in Muscle Tissue

  • Exercise produces temporary changes in muscle tissue including microscopic tears and increased blood flow to the muscles.
  • Short-term muscle fatigue is common as the muscles run low on energy sources, accumulating waste products such as lactic acid.

Vasodilation

  • The body undergoes vasodilation during exercise - the process of blood vessels widening to increase blood flow to the active muscles.
  • This supports higher oxygen delivery and waste removal from the working muscles.

Energy Systems

  • Short-term exercise usually relies heavily on the body’s anaerobic energy systems.
  • These systems provide fast energy through the breakdown of glycogen into glucose without the need for oxygen, but produce lactic acid as a byproduct.
  • The ATP-CP system provides immediate energy for high-intensity, short duration activities, while the lactic acid system extends energy supply when the activity continues beyond a minute or two.

Blood Sugar Levels

  • During exercise, the muscles use glucose for energy which leads to a drop in blood sugar levels, prompting the liver to release stored glucose to provide additional fuel.

Release of Endorphins

  • Exercise prompts the release of endorphins, chemicals in the brain that act as natural painkillers and mood elevators. This is often referred to as the “runner’s high”.