Hmmm. The formula for max heart rate is 220 - age, so President Bush comes in at 220 - 58 = 162 bpm. That's what he should be maxing at. All he really needs for conditioning and weight loss is 85% of max, so a real workout max for him should probably by (162 x 0.85 =) 137.7 .
I'm not a cardiologist, but I spend a lot of time with them now :-( . So this isn't a professional opinion, but my hunch is the President might be wise to cool it a little.... After all, we want him around for a very long time!
The 220-age applies to the average population, and not to athletes. The average population being of course quite sedentary. I am 50 y.o. and maintain about 175 bpm during a 40 km time trial (road cycling). Of course the "instructors" at a place like Bally's Total Fitness can not grasp that, since:
1. I should be dead at that heart rate.
2. I'm not capable of more than 30 minutes walking.
W is in the shape of a master's athlete. I'd like to see if he shows up at the Lajitas mountain bike event in 2009. KICK BUTT!