After extensive research and data collection, several conclusions could be made. A notable difference in the rates of muscle glycogen accumulation after exercise existed between trained and untrained individuals. Data taken at 0, 6, and 48 or 72 hours post exercise revealed that the amount of glycogen in trained subjects was significantly higher than the amount of glycogen found in the untrained group. Figure 1 illustrates these findings.

The average muscle glycogen concentration in trained subjects proved to be higher than that of the untrained ones. This trend seemed to follow the time period starting immediately after exercise to 48/72 hours post-exercise. In addition, muscle GLUT-4 content was almost three times higher in trained than in untrained individuals. (Fig. 2)

The fiber types of the muscles of each subject was also investigated. On average, trained individuals showed a larger percentage of type I fibers in comparison to untrained individuals. These trained individuals also demonstrated a smaller percentage of type IIB fibers than the untrained. There was no difference in the IIA fiber percent between these two groups. Other findings indicate that no correlation existed between plasma CK concentration and the rate of glycogen accumulation at 6 or 48/72 hours after exercise. However, there was not enough statistical evidence to prove this. There was no difference in the oxygen uptake relative to VO_{2 peak} between trained and untrained individuals during the endurance ride.

Q: What's the difference between Type I, Type IIA, and Type IIB fibers?
A: Everyone has a different percentage of these types of fibers in their bodies. What determines how much of each type you have depends on genetics.

• Type IIA muscles are the muscles to use when you're thinking of going to the gym for a couple hours. They are the muscles designed to work long periods of time. They also have high levels of GLUT-4.
• Type IIB muscles are the ones used for temporary high power outputs. They're the ones you need when you realize you have 2 minutes to sprint across campus to take your Biology final! These muscles have now levels of GLUT-4.
• Type I fibers contain high GLUT-4 levels, like IIA. They contract slowly, but they're good at oxidizing substrates like glucose and fatty acids.

Q: Initial oxygen peak. Uh-oh, that sounds pretty complex. What does it mean?
A: Don't worry, it's a pretty simple. A VO_{2 peak} is the maximal rate of oxygen utilized by the entire body. You can find this rate by taking the product of the maximal amount of blood your heart can deliver (maximal cardiac output) and the maximal amount of oxygen that can be extracted from the blood by the tissues (maximal arterial-venous oxygen difference).

Q: Why do I care about plasma CK?
A: Put Calvin Klein aside, CK stands for "creatine kinase." In this study, plasma CK is used as a measure of muscle damage caused by the exercise. High levels of CK in the plasma indicate that muscles cells are leaking due to torn or bruised muscles.

Q: Figure 1 measures glycogen in "wet weight." Did they dip it in water first?
A: Um, no, but that's a close guess! Since our muscles are 75-80% water, some investigators (not the ones in this study) freeze-dry their biopsies before analyzing them. Thus, "wet weight" refers to the weight of the muscle biopsy with its full water content.

Q: OK, so you've told me all the facts and used all your fancy words. So hotshot, now tell me what it all means.
A: All shall be revealed in the Discussion Section.