Lightheaded after intense workouts

I just started going to my local fitness center for treadmill walking.
I've been sidewalk walking for most of the summer, but I find it difficult to get my heart rate above 120 on the level surface without running (and I don't want to run - bad knees & back.) My pace was about
4 mph.

I'm 41, and had a mostly blocked right coronary artery in Feb of this year which was angio'd and stented. Doc had me on a "standard" course of meds: Plavix, Lovastatin, Metropo, Lysinopril, Asprin. He's ended up removing me from all of them except the asprin as I've checked out A-OK on my EKG's, blood work, blood pressure and Stress Echo - no muscle damage whatsoever and I didn't/don't have hi-BP (115/75-ish with a resting HR in the 40's) or abnormal blood lipids.

At the gym, I've been pushing myself on the treadmill - 3.6mph and 10% incline for about 40 minutes. Heartrate is in the mid-140's and it feels like a good workout with no leg, chest or other pains. Problem is that
I'm very lightheaded after I step off the treadmill - my balance is skewed where it's difficult to walk a straight line. I don't feel any of this while on the mill and I *do* cool down with 5 mins at very a slow paced walk. It all clears up within a few minutes.

Is this something to be medically concerned about or is it perhaps due to sending a great amount of my blood supply to my legs for the exertion and not allowing enough time to recover?

By all means check this out with a medical professional but this can be a normal reaction when stepping off a treadmill after a long workout.
The ground still appears to move and this creates a sensation of vertigo. With your hightened awareness due to your recent medical condition, every little abnormality may be getting a lot more of your attention. I can understand that.

Thank you for the reply Julianne. For the past several workouts on the treadmill I've paid special attention to pinpoint exactly what the sensation is and where I feel it.

I think it's really a case of rubber legs. I've been doing up to 40 minutes of roughly 4 mph/10% incline. When I stop and walk away, I feel like I'm floating on my feet. I don't feel dizzy or anything in my head at these times, though I've always been susceptable to the dizzies when rising from lying down or being seated.

I've modified the 5 minute cool-down so that the treadmill *really* slows down by the last minute. I think it's only going about 1.5 mph,
IIRC, and I stand on the mill for about a minute after it stops. This seems to have solved my floaty feeling. I have rather muscular legs compared to the rest of my physique - so I think you're right with the blood pooling angle.

I'll continue to be aware of the situation, but think it's by and large benign - unless I fall into some pumped up, testosterone oozing hulk...

Yeah - nuts/seeds are excellent - good fats, fiber, protein. I'll have

press machine - you may feel faint - your blood can pool in the legs.
For me, caffeine is necessary before a workout. If you've never tried coffee before a workout you may want to try it - it really gets the motor running!

I still do that after years of treadmill exercising. I go every morning between 3.5 and 4.0 miles an hour at varying inclines. One explanation I have read is that the vasculature in your legs expands to feed the very large muscle groups and when you stop, blood tends to pool causing a reaction similar to orthostatic hypotension. If you posted this anywhere else, I would say don't be concerned. However, since you have a history of cardiac disease, you should really check with your doc. Even if my explanation is correct and it is just transient hypotension, he or she may want to know about it as stents like a certain pressure flowing through them. Or maybe it doesn't really matter. (I was the critical care nurse in my clinical days- who knows what happens to patients after they get discharged But, it certainly is worth a phone call.

One option may be to get a referral to a cardiac rehab facility if only for a few days so that you can be monitored while you exercise. After they clear you, you can head back to the regular gym.

When I get off the treadmill (after a very dramatic cool down), I make it a point to not stand still for a few minutes. I wander through the house on the flat surface and may do one or two domestic chores that don't require standing. It has become habit to lift up on my toes and to tighten my thigh muscles when I first stand still to mechanically move the blood out of the tissues. Works for me.

Blood sugar, as Brad suggested, is also a possibility but it seldom self corrects without intervention and after all your hospitalizations, someone should have picked up on it by now.

Great job exercising. I used to feel lightheaded after an intense workout - but it's odd you'd feel that way after a 5 minute cool down.
By all means tell your doc. I'd suggest a lower incline until your doc clears you. One thing that helped me was eating saltly peanuts after a workout. A long workout may deplete sodium. Another possiblity is low blood sugar - you could try Gatorade,etc to see if that helps. For (I think) the best info on working out, etc see www.drmirkin.com I believe his archive covers faintess after working out.

Perfectly normal, in my experience.

I had the experience again today but this time paid particular attention to the sensation... it's not a dizzy feeling as much as a floating on my feet feeling. Maybe rubber legs to the N-th degree. I don't feel as though I'm going to faint, just not totally in control of my legs. (If I wasn't concerned about stumbling into someone else and looking like a goober, it would be almost comical.)

One other thought if Dr. Chung is listening: I just stopped the
Lovastatin and Lysinopril within the last 10 days or so. Doc just told me to go cold turkey. Could there be any lingering effects from either of these two drugs?

The low blood sugar is an interesting angle. I've been anti-hi-glycemic eating for the last 6 months. Little if any refined flour or sugars.
Much of my diet is protein and green veggies with some fruit thrown in for good measure. Maybe I should eat a piece of fruit before the workout?