If you're overweight, that means you have too much unused energy lying around we call fat. The reason why you feel as if you're running out of energy is because your muscles weren't used to being stressed before. Just give it time and stay in your routine and watch what you eat. Dramatically cut down you salt and sugar consumption and drink a lot of fluid. Also don't forget to do a 10 minute breathing exercise after the work out to help your system restore the oxygen in your blood. Energy drink is not good for you if you're trying to lose weight. Because if you have extra weight, your heart is working really hard during a work out and an energy drink will just stress your heart even more which will eventually result on many health problems like high blood pressure.

If your looking for more energy you'll need to have some carbs. About 20 mins before you work out. Some good carbs to take in that will help with your diet and energy level are veggies, oatmeal (this is a good one, packed with fiber, carbs and low calorie), whole wheat bread and / or pasta (take these in moderation), and fruits. Be careful with fruits although very healthy for you, they still can pack in quite a bit of sugar. I would recommend eating fruit early in the day so you body can process it and use up its energy through out the day, as oppose to storing it late in the day.

If you eat right before you go to the gym, that food is not available for energy yet. You should eat a couple hours before you work out. Try to eat some fruit, yogurt and some healthy carbs. Make sure you are not cutting your calories so much that you are depleting all your energy.

There are plenty of healthy food that can give you energy to work out. These include soy milk, wheat bread and brown rice.