Aerobic Training

Aerobic Training and Why It’s Important for Runners

When it comes to running, we rely on two main energy systems: aerobic, which means "with oxygen," and anaerobic, which means "without oxygen." Aerobic training occurs when our body uses oxygen as its primary source of energy, while anaerobic training happens when our body burns carbohydrates instead, producing lactate as a byproduct. An easy way to differentiate the two is to think of aerobic running as training for a marathon and anaerobic running as training for a sprint.

Did you know that distance running is primarily aerobic? When racing:

• A marathon is 99% aerobic
• A half marathon is 97% aerobic
• A 10K is 90% aerobic
• A 5K is 85% aerobic

Since distance running relies so heavily on the aerobic system, the majority of our training should focus on improving it.

Benefits of Aerobic Training:

• Increased capillary density – Capillaries supply blood to muscles. The more capillaries you have, the more efficiently oxygen-rich blood reaches your muscles.
• More mitochondria – Mitochondria convert fat and carbohydrates into fuel, improving endurance.
• Higher aerobic capacity – A greater aerobic capacity (VO₂ max) allows your body to use oxygen more efficiently, helping you sustain faster paces while staying aerobic.
• Greater fat utilization – Training aerobically encourages your body to burn fat instead of carbohydrates, leading to more stable blood sugar and energy levels. Since fat stores are much larger than carbohydrate reserves, this helps sustain endurance performance.

The more you understand about aerobic training, the faster and more efficiently you’ll run!