Training in sports involves developing various abilities through different methods. These abilities include strength, endurance, speed, flexibility and coordination. Strength training can be isometric, isotonic or isokinetic. Endurance is developed through continuous, interval and fartlek training. Speed is improved through acceleration runs and pace runs. Flexibility involves static, dynamic, PNF and ballistic stretching. Training also follows periodization of macrocycles, mesocycles and microcycles to peak for competitions.