Lesson 1, Topic 1
In Progress

Energy Pathways

All energy systems work continuously

The relative contribution of an energy system to a particular physical activity depends on the energy requirements, which are directly related to the intensity and duration of the exercise, different events have a different load (intensity and volume).

Different events, therefore, emphasize different energy systems-

  • Predominant aerobic: Marathon
  • Predominant anaerobic lactic: 100m
  • Predominant ATP / CP: 30 m

Share of energy supply mechanism during different track and field events

DistanceATP / CRPH %anaerobic-lac %aerobic %
30 m80191
60 m55432
100 m25705
200 m156025
400 m124345
800 m103060
1500 m82072
3000 m51580
5000 m41086
10000 m3-212-885-90

Cardiopulmonary System


  • Surface ,
  • Size
  • Amount
  • location

Circulatory adaptability

Perspiration and flushing skin

Blood circulation reacts to the demands:

  • Homeostasis (balance) of the body heat thermoregulation               
  • 60 – 70 % of energy in the human body is degraded to heat
  • Muscles Works
  • Digestion

During exercise

  • Heart rate  – Increases
  • Lungs – operate faster and at a greater capacity
  • Blood vessels  – dilate, get wider, where oxygen is needed, constrict, get narrower, where oxygen is less needed
  • Blood flows faster


  • more oxygen to the working muscles                          
  • increased VO2max