Muscle strength is the ability of a muscle group to exert a large contractile force for a single repetition. Muscle endurance is the ability to perform repeated contractions against resistance for a prolonged period of time. The idea of strength endurance is, therefore, to be “stronger for longer”. To be able to exert a high contractile force over repeated contractions for a prolonged period of time.
24-hour cycling races are ultimately strength endurance challenges. The stronger you are, the less effort a steep climb will feel and the more comfortable you’ll be. If you’re looking to be competitive, you need to be able to deliver sustained power for prolonged periods of time. Yet you’ll also need the endurance to get around lap after lap, kilometre after kilometre.
How to develop it
Following conventional wisdom, you develop strength with high weights and low reps and you develop endurance with low weight and high reps. The trick to strength endurance is to combine, high weight and low rep with short rest periods and high volume training.
The high weight and low rep is simple. Without heavy weight, you won’t develop strength. The high volume accounts for the fact that without high volume, there is no benefit to endurance. The short recovery periods are to train the body to recover faster and to allow it to exert maximal force while not fully aerobically recovered.