He may need to undergo a sleep study for sleep apnea; there's one type where the throat closes off (obstructive) and another where the brain forgets to breathe on a regular pattern. High blood pressure and a racing heart could definitely be symptoms of sleep apnea. Even if he doesn't have either type of apnea, a sleep study could monitor the events so a doctor can get a better picture of what is happening from the brain and heart monitors.
My husband had the same problems you have and has NOT biked in over five years and is relatively sedentary, so I don't believe it is exercise or bike related. His testosterone was even lower than yours and he should be at around 1100 at his age. He started with the Androderm patches, but they refused to stay stuck on his skin and would fall off in places where it could be dangerous (children, women, and animals should not come in contact with the patches).
He then tried Axiron and it has doubled his testosterone level over a matter of two months on a single dose (this is a gel applied to the underarm). He just got approved to increase his dose to two (both underarms), and may have to increase to three (both underarms, let dry and reapply on one underarm).
He said he had reduced appetite, moodiness (similar to female PMS moodiness), agressive urges (driving fast/close to ther cars, snapping at people, yelling at the kids) but these diminished after about a week of adjusting. His libido has increased dramatically (from once a week to once or twice a day sex) and he has healthy strong erections (definitely not psychological ED).
With insurance his treatment is about $91/month (US), but it may vary with different insurance carriers. Without insurance it is close to $300.
Once the medication is applied (usually in the morning after showering, applying deoderant and waiting two minutes), you wash you hands and let the medication dry for about 20 minutes before putting on a shirt. In the afternoon you can wash your underarms and then the skin is safe for other people to touch, otherwise a layer of clothing needs to be between you and another person's skin or they run the risk of absorbing the testosterone, and no one except you should handle you shirts without rubber or medical gloves.View Thread