More time is what you need. If you try to break the records (so to speak) you will fatigue the body, injure muscles (all exercise injures muscles - in fact many purposefully injure the muscles to cause them to grow - this is what weight training does) so you will be stiff, sore and seem to be out of shape even more than you are. Ideally you need time to 'get into shape'. Practically there are a few things you can do to nudge the results. 1. Walk more during the next few days - adding a little bit more exercise in your daily routine. Meaning take a flight of stairs to get into the office, or park further from the office/store doors - adding a few more steps to each and everything you do will slightly improve your endurance in the short run (like a week). 2. Get plenty of rest at night (at least 8 hours) and drink plenty of clear liquids - clear liquids are any liquid you can see through like water, apple juice, grape juice. 3. 20 too 30 minutes prior to the test itself eat a small portion of high carbohydrate (low processed sugar, something along the lines of bread, rice, a staple that will convert too sugars in your body). This will give you a spurt of extra energy 20 to 30 minutes later as the carbs are converted into 'natural' sugars and released slowly into the blood stream. Beyond that there is not anything else you can do this close to the test.

find some tall buildings. take the stairs up and the elvator down. a football stadium. any stadium.