Question

1) Select one stress-hormone and one water-hormone and describe how they change during an acute bout of aerobic exercise. Next, describe how their actions help to provide energy and conserve water, respectively, during exercise.

2) Describe how chronic aerobic training impacts the events at the neuromuscular junction. Does it speed up the transmission of information or slow it down? What effects does this have on performance? What other variables influence these events?

Answer 1

1)Stress hormone- ADRENALINE OR EPINEPHRINE :

it is produced by adrenal medulla of the adrenal gland.

As aerobic exercise is a physical stress our body responds to it by releasing adrenaline.

It increases the cardiac output and also constricts the blood vessels in parts that are not involved in exercise so that more amount of blood is supplied to the muscle involved in aerobic exercise.

It elevates the blood glucose levels by glycogenolysis and also supports the fat metabolism thus providing energy during exercise.

Water hormone-ADH orANTI DIURETIC HORMONE :

ADH is secreted by hypothalamus and stored and released by posterior pituitary gland.

During aerobic exercise there is profuse sweating due to increased muscular activity.

As a result the concentration of electrolytes increases leading to increased blood osmolality

This stimulates the osmoreceptors in hypothalamus which stimulates the posterior pituitary to release ADH.

ADH acts by increasing renal tubules and collecting duct permeability to water thus conserving the water.

2)chronic aerobic training influences NMJ both physiologically and anatomically.

Physiologically excercise training increases the saftey margin and also alters the spontaneous release of neurotransmitter so that resistance to fatigue is developed.

And there is increased motor units which respond simultaneously so that there is increased force production.

Aerobic exercise speeds up the transmission of nerve impulses as there is increased sympathetic stimulation.

Due to this all muscles show synergistic effect .

Anatomically there is hypertrophy and hyperplasia as an adaptation to increased