The main result you notice is that you start breathing hard in order to supply the oxygen to your body so it can undertake this process of respiration. The unit of work in the metric system is the joule. One joule of work is done when a force of one newton is applied through a distance of one meter. Either way you apply the same force through the same distance so you do the same amount of work. However in the running case, you develop more power.
Power is work per time.
Speed is the rate of covering distance, interest rate is the amount of money per year, and work per time could also be called the rate of doing work. Let's say a clunkey old car and a powerful sports car happen to weigh the same and they both climb the same hill. Since they weigh the same, they must exert the same force, and since they both go the same distance, they each do the same amount of work. However, the sports car does it much quicker because it has a much more powerful engine. The metric unit of power is the watt.