Each package of energy gels constitutes as one serving, ranging from 80-110 calories. The dosing instructions vary from pack to pack. Some advise that you take one before your exercise and another thirty minutes in.
It is always important to listen to your body. If you still have high energy levels and aren’t ready for another burst, wait. Take the next pack when you feel you are running low on energy. Energy gels typically come in a thin, plastic container which makes them easy to carry a couple along in a pocket or backpack.