why does exercise hurt?


why does exercise hurt?

In: Biology

Muscles require oxygen to function their peak level. Oxygen is delivered to the muscles by hemoglobin in the blood. Blood delivery is a function of cardiac function.

When you exercise, your cardiac rate increases which increases blood flow which increases oxygen delivery. *BUT…* at some point your blood flow often (especially when one is not in peak athletic shape) cannot keep up with the oxygen demands of muscle tissue. When that occurs, and when you are still working your muscles, your muscles’ cells switch from aerobic respiration (using oxygen) to function, to anaerobic respiration (no oxygen). Anaerobic respiration has a byproduct known as lactic acid which can build up in muscle tissue and blood stream and causes physical pain. The body takes this as sign (by inducing pain) to slow down and let oxygen/blood flow catch up and switch back to aerobic respiration.

During exercise, our muscles repeatedly contract and relax. This cycle required energy. The energy comes from breaking down sugars. Now, because we need a lot of energy, during a short span while exercising, there is no time to get oxygen so the sugar is broken down without it, leading to lactic acid production. This build up of acid eventually leads to muscle soreness.

I would argue you’re doing it wrong. Exercise shouldn’t hurt, or you’re over exerting yourself. Typically, people who don’t know how to exercise have initial pain when they start, but condition themselves and it’s no longer a problem. That doesn’t have to happen in the first place. Slow down, take it easier, do less. If you’re looking for a lifestyle change to include exercise, then you have the rest of your life to get in your hustles, but it’s *really hard* to build the discipline that is a new habit, and any amount of discouragement shuts down an individual with good intentions.

If you’re older, like me, then you can’t do the high impact stuff like the younger folk. Instead of jogging, get on an elliptical or bicycle.

Because when we exercise intensely, we have to get energy from a reaction called anaerobic respiration. This produces lactic acid, which makes our muscles sore because it is acidic.