The formula for cellular respiration is the opposite of photosynthesis in a way of remembering it. Glucose (C6H12O6) + oxygen to break it down makes 2 waste products. 6H2O (water) and 6CO2 (carbon dioxide) The most important product would be ATP that the cells use for energy, but I am assuming you wanted to know about what is released. Example: When you exercise, you breath in more oxygen which breaks down more glucose which makes more ATP. That’s why you feel tired. And you start to breath out more and release more CO2 as a waste product being released. Hope this helped!