The Pathways

Well, today was yet another rest day, due to it being back-off week and all! So I thought I take the time to talk about some of the energy pathways we use when we exercise.

I am going to talk about aerobic and anaerobic.

The Anaerobic (ATP-CP) Energy System
Adenosine Triphosphate (ATP) stores in the muscle last for approximately 2 seconds and the resynthesis of ATP from Creatine/Phosphate (CP) will continue until CP stores are depleted, approximately 4 to 5 seconds. This gives us around 5 to 7 seconds of ATP production.

To develop this energy system, sessions of 4 to 7 seconds of high intensity work at near peak velocity are required e.g.

3 × 10 × 30 metres with recovery of 30 seconds/repetition and 5 minutes/set.
15 × 60 metres with 60 seconds recovery
20 × 20 metres shuttle runs with 45 seconds recovery
The Anaerobic Lactate (Glycolytic) System
Once the CP stores are depleted the body resorts to stored glucose for ATP. The breakdown of glucose or glycogen in anaerobic conditions results in the production of lactate and hydrogen ions. The accumulation of hydrogen ions is the limiting factor causing fatigue in runs of 300 metres to 800 metres.

Sessions to develop this energy system:

5 to 8 × 300 metres fast - 45 seconds recovery - until pace significantly slows
150 metre intervals at 400 metre pace - 20 seconds recovery - until pace significantly slows
8 × 300 metres - 3 minutes recovery (lactate recovery training)

HIIT and tabata style workouts are ideal for anaerobic conditioning. This style of training is also now thought to be better for fat loss than aerobic training due to the after affects of a workout. Bodyweight routines are also excellent for anaerobic conditioning, such has the HIIT and tabata mentioned as well as minute drills.

The Aerobic Energy System
The aerobic energy system utilises proteins, fats and carbohydrate (glycogen) for resynthesising ATP. This energy system can be developed with various intensity (Tempo) runs. The types of Tempo runs are:

Continuous Tempo - long slow runs at 50 to 70% of maximum heart rate. This places demands on muscle and liver glycogen. The normal response by the system is to enhance muscle and liver glycogen storage capacities and glycolytic activity associated with these processes.
Extensive Tempo - continuous runs at 60 to 80% of maximum heart rate. This places demands on the system to cope with lactate production. Running at this level assists the removal and turnover of lactate and body's ability to tolerate greater levels of lactate.
Intensive Tempo - continuous runs at 80 to 90% of maximum heart rate. Lactate levels become high as these runs boarder on speed endurance and special endurance. Intensive tempo training lays the base for the development of anaerobic energy systems.
Sessions to develop this energy system:

4 to 6 × 2 to 5 minute runs - 2 to 5 minutes recovery
20 × 200m - 30 seconds recovery
10 × 400m - 60 to 90 seconds recovery
5 to 10 kilometre runs

The fact that this type of training uses fat has an energy source was the reason many thought it was the best way to lose weight, but we now know interval type training speeds metabolism up long after the workout is finished.

And remember, aerobic doesn't mean easy!!!!!

Thanks for reading.
Jamie.