When you do not exercise often after you go back to it delayed onset muscle soreness (DOMS) may occur. If you exercise exceptionally hard you can get runners high, which combined with elevated endorphin levels means that you may not feel pain sharply while you are exercising.

Delayed onset muscle soreness can occur anywhere from a few hours to about a week after strenuous exercise. DOMS occurs more commonly when people do peak athletic type events, but is also common when people who have not exercised much start up an exercising program.

Sometimes starting exercising becomes a wall which people feel they can’t scale. When you don’t work out and then you suddenly get pains the first time you do exercise then you may associate exercise with the pain. The thing is, one of the best treatments for DOMS is further exercise.

This article covers DOMS in depth, and offers the following tip:

Although the relief is temporary, exercise of the sore muscle probably is the best way to reduce DOMS.

Examples of DOMS: Flat Foot & Hosed Ankle:
I am exceptionally flat footed. Although this will sound a bit random, one time my left foot and ankle got ran over while I was still in the car (idiot driver using 2 feet). Years later my ankle is one of the first things to hurt whenever I exercise.

My favorite sport to play is basketball, and recently I have also been playing tennis. Due to the sharp movements these sports place a ton of stress on my ankle. I normally feel minimal pain while I am exercising, but notice it significantly a while afterwards.

The mind and body build up a tolerance to anything though. The more you are used to something the less it hurts. This means that after the second or third time you exercise the pain should likely not be as strong as it was after the first time. So you have to get past the innitial pain to really notice the benefits of exercise.

Another Example of DOMS: Wearing a Football Helmet:
I played football my sophmore year of highschool. After wearing the football helmet for one day it hurt extrordinarily bad. I played another day or two and my neck muscles and body adjusted. The pain disappeared.

I was the guy who played against our all state linebacker in tackeling drills, and I can assure you that it usually hurt though

Weight & Stress:
As your weight goes higher the stress from exercising is much greater. Sounds logical obviously, but if you are having trouble doing strenuous exercise you may want to start off by doing things that are a bit less strenuous and working your way up. Also if your diet is exceptionally bad sometimes you can lose weight by doing nothing.