Exercise and Oxygen Debt

• When we exercise, our bodies need to carry out more solar respiration because all exercise requires us to move our muscles more than usual and any muscular contraction requires a lot of energy which we have to get from respiration.
• The rate of our breathing and the volume of each breath increase when we exercise to get more oxygen to our muscles.
• The increased effort we put in during exercise means that we can supply enough oxygen to all of our muscles and continue to use aerobic respiration.
• During high intensity exercise such as sprinting or cycling, there may not be enough oxygen to keep up with all of our demands and our cells will have to start using anaerobic respiration as well.
• Anaerobic respiration is less efficient than aerobic respiration but if there's no spare oxygen left, it's the best option our muscles have to get the energy they need.
• The main problem with anaerobic respiration is that it produces lactic acid as a product which builds up in our tissues and gives us a burning sensation in our muscles after exercise.
• After exercise, our bodies need to get rid of all of this lactic acid by reacting it with oxygen, which is why we have an oxygen debt.
• The oxygen debt is repaid when we double over and pant after a raise.
• To investigate the effects of exercise on the body, the main two things we can measure are breathing rate and heart rate.
• To measure somebody's breathing rate, you just count how many times their chest rises and falls in a given amount of time, generally for one minute.
• To measure somebody's heart rate, you can just measure their pulse which you can do by placing two fingers on an artery in their wrist or in their neck.