Why is it important to hold a static stretch for at least 10–15 seconds? Include the physiology of the stretch reflex in your response. 2–3 sentences

Static stretch

Explanation:

Static stretching exercises are done by elongating the target muscles as tolerated and then holding the stretch in that position for a stipulating length of time. This holding time period is usually determined by the individual’s age, activity level, any other previous illness or injuries etc.  

The holding time usually is around 10-15 seconds is especially done to:

The main physiology in stretch reflex:

The stretch reflex is a myotatic reflex which is triggered by the action potentials of la afferent fibers. This causes the excited motor neurons to contract the stretched muscle which in turn reduces the potential.    

The holding in static stretching is to make the elongation of the muscles a habitual length for the muscle spindle fibers and mark it is a new length.

The signals are reduced and the receptors are trained to allow more muscle fiber lengthening. The greatest increase in length or increase in range of motion occurs when the stretch is held for about 10-30 seconds with 2-4 repetitions.

you may having too much sleep.. a good night sleep consists of about 7 hours. more than that could be the reason you're still tired throughout the day.