Question

During several months of stay at home orders to combat a coronavirus outbreak, Rebel and Victoria ate large amounts of junk food while binge-watching Netflix. When the stay at home order was lifted, they were woefully out of shape and none of their clothes fit so decided to join a Crossfit class. The day after their first class, they were both in agony and could barely move from the pain in their arms and legs. What is the most likely reason for their muscle soreness and how would you explain the physiological pathway to them?

Answer 1

The muscle soreness felt by them is due to accumulation of lactic acid in their muscles.

As both Rebel and Victoria have just started to do the exercises, their muscles are not used to such workload. Lactic acid accumulate in muscles when muscles do not get enough oxygen. Anaerobic respiration occur in muscle. In absence of oxygen, the glucose which has to be converted into carbon dioxide and water, instead converts into lactic acid by anaerobic process.

This accumulation of lactic acid cause soreness in muscle.