Now, overnight, what happened was the cells of our body used up their supply of glucose and glycogen. And so as soon as we go for that morning run or swim, our cells will depend on triglycerides to actually form the ATP molecules that are needed to carry out those particular cell processes. And so the question is, what actually initiates the breakdown and the mobilization of triglycerides within our fat cell in this circumstance? Well, basically specific types of hormones. So we have hormones such as glucagon and epinephrine that can initiate the breakdown of the mobilization of triglycerides. So we have some type of primary messenger molecule.