A note of caution here - the other day I went to the gym (on a Tuesday) after I had used a 10 mg Cialis on a Monday. It was my first time ever to the gym, so I didn't know what to expect. After running around a track for about 15 minutes and then another 5 minutes on an elliptical machine cranked up on full incline and high resistance (never tried one before and wasn't trained in on how to really use the machine), I had to take a break.
I ended up walking about 50 ft before the world started sounding like it was coming at me in a tunnel and I felt like I was going to pass out. To make a long story short - I did.
I fainted sitting up with my eyes open, and was out for about 4-5 minutes while the Mrs. her finished up time on the elliptical and came over and noticed I was not responsive. She got kinda freaked out and got some help from a personal trainer and they called the paramedics & the whole 9 yards. As soon as they moved me from a sitting to a laying position, I came to and was a little woozy but otherwise fine. The paramedics came and I had pretty low blood pressure when they sat me up.
They ended up wheeling me out of there on a stretcher (nice first impression at the gym, right!?) and took me to the back of the ambulance and monitored my heart and blood pressure and asked me some questions, including whether I take any prescription meds daily. I said "no", since I don't, but I probably should have let them know I had had a cialis the night before (I didn't mention it). They told me I was dehydrated and let the Mrs. drive me back home and I rested up for the rest of the evening.
Poking around later on
this website, I saw this bit about possible side effects for Cialis.
Cialis can cause dizziness, lightheadedness and fainting if you get up too quickly. Alcohol, hot weather, exercise or fever can make this more likely.
I now think that in addition to being dehydrated, the cialis probably played a part in me fainting - which wasn't much fun. This was with the 10 mg cialis prescribed by my doctor (and before the Indian 20 mgs arrived in the mail). So, I plan on monitoring more carefully when I use it, and planning not to be working out the following day (and drinking a bunch more water and cutting down on the coffee). Still think it is useful and has a place in the sex kit, but it is good to remember that it is a prescription drug for a reason, I guess.