[Higher - Further - Faster].

The striated skeletal muscles consist of different myocytes that have different metabolic and contractile characteristics. They react in a specific way to difference training stimuli: adaptations as a result of endurance training trigger an increase in mitochondria and lead to an intensified oxidative metabolism. Adaptations as a result of strength training result in increased protein biosynthesis and hypertrophy of the skeletal myocytes. About 50 % of the adaptation associated with endurance training are due to genetic factors.The molecular mechanisms that underlie the training adaptations are currently the subject of intense research. They comprise complex interrelated systems with a series of key components. Understanding molecular switches and signalling pathways gives rise to the assumption that the combination of simultaneous strength training and endurance training is counterproductive. The combination of both these forms of training possible weakens the effect on muscle mass and muscle strength. Consequently the recommendation is to plan for enough of time intervals between strength training and endurance training.