Muscular endurance may be described as the ability for a muscle or group of muscles to perform a series of repetitive movements, without undue fatigue.
We can use weights to achieve this by lifting lighter weights over a relatively long duration.
For example, a set of shoulder presses ranging from 15 - 20 reps, 30 seconds rest, and repeat another 3 - 4 times.
We may also use our Martial Arts training to achieve the same result. However, instead of lifting under load, we are using body mechanics to incorporate the rest of the body and the training will be much more specific to our goals.
Lets use a series of round kicks as an example. It is quite demanding to continually round kick thai pads using the same leg for a set number of reps or time. After a short amount of time, your legs will become heavy and you will experience a loss of speed and power and increased fatigue.
The muscle has become tired and lactic acid is produced which gives the burning type sensation. This is the body's way of trying to keep up with the demand for energy you are requiring your body to deliver.
The answer to overcome this build up of lactic acid is quite simple. Train!!
You will become accustomed and your body will learn how to deal with the lactic build up more effectively.
You will not require as much rest time before you can go again and you will be able to perform harder and longer.
Therefore, sometimes, it is far more beneficial to train in explosive/plyometric type movements than slower strength work.
Saying that, we should all endeavour to combine our conditioning regimes so that we increase our aerobic/anaerobic thresholds as well as muscular strength and endurance.
Rest is essential for any growth or development though as overtraining may result in injury.
Train hard, train clever!!