Hi Diane,
I will recommend whole wheat pasta, for eating the night before - it provides great carbohydrates and a rich source of fiber and other important nutrients. I believe you are drinking sufficient amounts of water, you may need to take about 4 oz of a sport beverage, if necessary. As for the day of the work out, sometimes is better to drink your meal so it can be digested quickly. Maybe up to two hours before your work out, then eat the bagel 1 hour before testing as suggested. You may continue taking alli, but I will suggest checking with your physician or coach.
Let us know if we cna be of any further help,
Sylvia Melendez-Klinger, MS, RD, LD, CPT - registered dietitian
Sylvia Melendez-Klinger, MS, RD, LDN, CPT - registered dietitian