Winter Olympics: Get some energy!

By Zoë Gamble

The Winter Olympics have now drawn to a close and we look forward to the Winter Paralympics in Sochi, Russia. Athletes from around the world have be competing in events such as speed skating, ice hockey, curling and snowboarding.

To help them achieve their best, these athletes are on carefully controlled diets. As you are sitting reading this, you are burning approximately 88 calories per hour.

Downhill skiers however, will burn off approximately 600 calories per hour, and cross-country skiers will burn off around 900.

The energy we need to keep our bodies moving, growing, and repairing injuries comes from the food we eat. The more we move (exercise) the more energy we need, so the more calories we must consume.

The prize for most calorie-consuming event in the Winter Olympics goes to cross-country skiing.

The athletes competing in this event will be sure to eat the right amounts of protein, fat, and carbohydrate. They’ll need a lot of complex carbohydrates that will get broken down slowly by the body and provide a steady release of energy.

Cross-Country World Cup 2012 by Cephas – CC-SA

In the downhill skiing event in Sochi, Matthias Mayer won the gold, with a time of two minutes 06.23 seconds. In the cross-county, skiathlon, event, Dario Cologne finished the 30 km course in 1 hour, 8 minutes and 15 seconds.

Finding the energy

Have you ever considered the different processes that occur within your body to turn food into sugars to provide energy for these different sports? Different chemical processes take place depending on whether we need a short burst of energy, or a sustained supply.

The longest competition a cross country skier can enter in the Winter Olympics is the 50 km (men) or 30 km (women). They need to use two different chemical processes to get them to the finish line – aerobic and anaerobic respiration.

If you’re watching the Winter Olympics or Paralympics this year, watch out for the different events, and see if you can work out which type of respiration is the main type occurring within the athlete’s mitochondria.

Aerobic respiration

Aerobic respiration is a process by which energy is released from food. It requires oxygen to work. Note: Respiration isn’t the same as breathing (or ventilation). 

This process takes place inside the mitochondria of cells, where all of the glucose is broken down.

3D image of a typical mitochondrion Image: BruceBlaus (CC-BY)

The equation for aerobic respiration is:

glucose + oxygen → carbon dioxide + water (+ energy)

Remember, if you are taking the higher paper, you’ll need to learn this equation represented as chemical symbols:

C6H12O6 + 6O2 → 6CO2 + 6H2O

Anaerobic respiration

Anaerobic respiration is also a chemical process where energy is released from food – however, it occurs in the absence of oxygen, and not all the glucose is broken down. The equation for this is:

glucose → lactic acid (+ energy released)

It is less efficient than aerobic respiration (not as much energy is produced overall).

When you sprint for a bus, or do a burst of intense activity such as downhill skiing, your body can’t keep up with the demand for oxygen, so anaerobic respiration is the main source of energy.

As cross country skiers may compete for several hours, the main type of respiration they need to use is aerobic. They wouldn’t get very far if they were only using anaerobic respiration – lactic acid would build up, causing pain and slowing the muscles, and they wouldn’t produce enough energy to keep them going until the finish line.

Want to test your knowledge? Click here for a quick test to make sure you’re on track.

To really push yourself, check out this video which will consolidate your learning for the higher tier exam:


Curriculum Links

Key Stage 3:

Biology (Material cycles and energy)

Cellular respiration

  • aerobic and anaerobic respiration in living organisms, including the breakdown of organic molecules to enable all the other chemical processes necessary for life
  • the word summary for aerobic respiration
  • the process of anaerobic respiration in humans and the word summary for anaerobic respiration
  • the differences between aerobic and anaerobic respiration in terms of the reactants, the products formed and the implications for the organism

Key Stage 4:

This science made simple blog intends to enrich, and give context to:

AQA GCSE Science BIOLOGY 2 Unit B2.6 Aerobic and anaerobic respiration


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