The not require the use of oxygen.

The first energy pathway is phosphagen. This energy pathway has a fast rate of ATP production and utilizes creatine phosphate. Creatine phosphate is also used to restore ATP after it breaks down to supply and release energy.  The second energy pathway is anaerobic glycolysis. This energy pathway is dependent on the energy that comes from glucose and uses this energy to form ATP. Anaerobic glycolysis also does not require the use of oxygen. This energy pathway takes place in the cytoplasm and breaks down the glucose into pyruvate. The third energy pathway is known as aerobic glycolysis. This energy pathway requires and uses oxygen to create ATP and to burn carbohydrates and fats. It occurs in the mitochondria and utilizes sustained energy production.
In the phosphagen pathway there is only a limited amount of energy for the muscles to contract because of the low amount of CP and ATP. Exercises for this need to be at a high intensity in a short amount of time. These exercises can include sprinting or weight lifting. With anaerobic glycolysis exercise or activities require a high intensity of energy in a somewhat long period of time. The time period can be anywhere from 30 seconds to 3 minutes maximum. The activities that use anaerobic glycolysis can be gymnastics or hockey. With aerobic glycolysis it has a slower rate of ATP production and is used more during lower intensity activities in a longer amount of time. These activities can include a marathon or swimming.
If I were training to run a marathon the pathway that would be my focal point of training would be aerobic glycolysis. This is because marathons require to be able to sustain energy for longer durations. The type of activities I would incorporate for my marathon training would be running for 3 days a week, then adding in some type of cross-training exercises for the days that I do not run, and taking at least 2 days to rest. I would use these activities because running for 3 days can help train and prepare my body for the long race. Cross-training will also be beneficial because not only does it help increase your endurance but it also helps to train many different muscle groups in your body. Having an understanding of the energy pathways can be very beneficial to your future training endeavors because all activities and sports require different types and amounts of training and training the correct way can lead to success.