Long workout tonight- How can I prepare?

Tonight I am going to an hour long lifting class followed by an hour long spin class. This will be the third Thursday in a row I have done this, and I really want it to work but both times before I barely had the energy to get through the second hour. How can I prepare my body to take this challenge on? I know I can handle it if I just figure out some strategies. Keep in mind that I am a vegetarian and also I cannot rest before class because I'm going straight from work.

Thanks!

Raisins are good for quick energy boost before working out. I definitely wouldn't have the energy to get through all of that!!

Eat a snack with carbs like fruit, toast with honey, yogurt, etc before the work outs and the use a sports drink during the workout.  But beware if your goal is weight loss not to overdo the calories before, during, or after a workout. It is easy to derail your diet this way.

Edit:  And make sure you are drinking plenty of water during the afternoon, you don't want to start your workout dehydrated.

I do that every week, sometimes more than once. I usually have a whole-wheat bread sandwich (fillling = protein source - my knowledge of vegie alternatives to protein is very small, but make sure you have somee good complex carbs and protein before you workout, to give you enough energy) about 1h30 before workout (while at work) and I have a sportsdrink instead of water (or both) during the workout. But bear in mind that the sports drink might mess with your calorie restrain.

thanks for the advice. i forgot to mention that i am allergic to wheat so bread is out as well.

Right up my aisle! 

I have 2 practices a day 6 days a week, ranging from half an hour to 2.5 hours (and on really hard days, two practices totaling 4 hours) so I know a lot about preparing for a workout (and am wheat free too!)

Best snack for me (pre-workout) are corn tortillas with pb (think pf quesadilla!), a piece of fruit, and some string cheese. Post-workout is always a meal (either dinner or breakfast). During a bike workout (that's over 2 hours) I eat gu's or cliff shot blocks, these help tremendously with fatigue, but that's the only workout that I'll eat DURING. (swim workouts+eating=nausea).

Eat well during the day, I'm a hs student, and have to walk quite a bit between classes. I bring snacks to eat all day (raisins, powerbars, sandwiches, ect.).

Drink A LOT of water the whole day- prior, during and post. I sweat a lot, and it takes a lot of water to keep my pee an almost clear color. Usually I end up drinking 64-80oz a day. 

Thanks a lot for the tips! It worked out great-- I had more energy than usual and I rocked the workout!