Congratulations on your high level of physical activity and for keep in such good shape! There are several possible causes of your symptoms, most of which are not serious.
One possible cause is simply that you are resting on your arms in such a way as to impair blood flow while in these positions. This is likely especially if it occurs at night, as many of us accidentally sleep on an arm, causing us to wake up with pins and needles sensations. If the symptoms do not occur any other time of the day or do not occur while you are up an about, exercising, or otherwise exerting yourself then I suspect this is all it is.
A rare possibility would be thoracic outlet syndrome. This does present often as pain, numbness, and tingling
in the arms and it is caused by pressure on the nerves of the arms as they run down from the neck, usually as a result of extra muscle mass (from being athletic) or an extra rib. Although rare, this syndrome does tend to present at about this age with increasing athletic activity, and it is worth having an examination by your primary care doctor
to be certain that this is not a possibility.