Endurance is the time limit of persons ability to maintain prolonged stressful effort or activity.
It can be enhanced by plyometrics exercises, circuit training etc. If your muscle endurance is low you wont be able to do any type of work for a longer period. For example if you are asked to carry a bag full of stones to 5 th floor of the building then do you think you can do it easily. Working out in a gym, cycling, swimming is some forms of exercises that can develop your endurance. It all depends upon the training intensity, frequency and time.