NoSpam wrote:
The only thing I'll add to Dave's response is...
Make sure you eat beforehand
and hydrated
If one thing gets me, it will be forgetting to drink
water before I head out. If there's a way to carry it
safely, consider taking a water bottle along.

And 35 minutes ain't bad. You won't see the
unlimited pilots going out for long workouts.

Finally, don't be a stubborn jackass.:-) Quit as soon
as you start to feel yucky. (The one thing I don't
enjoy is an instructor that wants to get the full
hour in, no matter what.)

Have fun doin the aeros, rick