Question

Specifically, what is the physiological basis behind the use of Beta 2 agonists, what are the side effects associated with its use, does it actually work, what type of athlete would benefit from its use, and is it banned in competition by the WADA and NCAA or NAIA?

Answer 1

Beta 2 agonists are the class of drug that acts on beta 2 adrenergic receptors present in various organs such as GIT, bronchi, detrusor muscles of uterus and blood vessels. The beta 2 agonist causes brochodilation and is used to treat COPD and asthma.
MECHANISM OF ACTION : The beta 2 agonists act on beta 2 adrenoreceptors in bronchi and increases cAMP production. This results in decreased intracellular calcium and increased membrane potassium conductance. Increased cAMP also  decreases myosin light chain kinase activity. This results in muscular relaxation and bronchodilation in lungs improving ventilation.
SIDE EFFECTS : anxiety, tremors, increased sweating, tachycardia, palpitations, hypokalemia

More severe side effects include cardiac arrhythmia, myocardial ischaemia and pulmonary edema.
Beta 2 agonists also increases blood supply to skeletal muscles thus facilitating muscle contraction. They also increase glucose uptake by the muscle cells. These effects increases performance in athletes. It benefits athletes involved in endurance sports such as cycling, swimming, marathon runners.
The world anti doping agency has prohibited its use and beta 2 agonists are banned in sports