Aerobic fitness – What is it and how can you improve it?

​What is aerobic fitness?
Aerobic fitness can be defined as one’s ability to transport and deliver oxygen to the muscles, so it can be utilised to generate energy to support the activity of the muscle during exercise (1)
There are three major components to aerobic fitness which can be viewed below (2).

1. Maximum oxygen uptake (Vo2max). This is the highest rate at which an individual can consume oxygen during exercise, and Vo2max is recognised as the best single measure of aerobic fitness.
2. Mechanical efficiency or economy. This is the metabolic or energy cost (measured as the oxygen cost) of any given intensity of exercise.
3. Fractional utilisation. This is the percentage of Vo2max that can be sustained for any given length of time (e.g. when you are cycling or running).

General exercise recommendations for increasing your aerobic fitness 3

• Frequency:
  •  ≥5 days/week of moderate exercise
  • OR ≥3 days/week of vigorous exercise
  • OR a combination of both - ≥3 - 5 days/week.
• Intensity:
  • Moderate and/or vigorous intensity benefits both Vo2max improvement and health outcomes.
  • Light intensity may be beneficial for deconditioned persons and beginners.
• Time:
  • Moderate intensity – 30-60 min/day (150 min/week)
  • High intensity – 20-60 min/day (75 min/week).
• Type: Incorporation of continuous rhythmic exercise using large muscle groups.

Training methods for increasing your aerobic fitness.
There are three basic forms of aerobic fitness training: continuous training, interval training and Fartlek training (4).

Continuous training
Involves continuous exercise such as jogging, swimming, walking, or cycling, at “somewhat hard to hard” intensities without rest intervals. The prescribed exercise intensity is maintained consistently throughout the exercise session.

Interval / HIIT training

• Long intervals: longer than 60s work effort
• Short intervals: less than 60s work effort
• Repeated sprint training: less than 10s all out sprint with recovery periods
• Sprint interval training: 20 – 30s all out sprint with recovery periods

​Fartlek training
Fartlek training or “speed play” is similar to interval training, but is a free form of training, which involves interspersing short bursts of intense/faster work throughout a continuous training activity. The exercise-rest cycle is not systematic or precisely timed and measured but is based on the feelings of the participant.

The bottom line
Completing some form of aerobic exercise is better than completing no aerobic exercise. If you’re not sure where to start, it is best to start with small increments (5 – 10 mins) of light intensity exercise (walking or cycling) and slowly increase the duration over time. Once you can comfortability tolerant this, look to start increasing the duration. Once you can complete greater bouts of aerobic exercise look to increase the intensity, eventually aiming to reach the recommended guidelines.

​Bec Dostan

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1. Armstrong, Neil, Grant R Tomkinson and Ulf Ekelund, ‘Aerobic Fitness and Its Relationship to Sport, Exercise Training and Habitual Physical Activity during Youth’ [2011] British journal of sports medicine
2. Lucia, A, Oliván, J, Bravo, J, Gonzalez-Freire, M & Foster, C 2008, ‘The key to top-level endurance running performance: a unique example’, British Journal of Sports Medicine, vol. 42, no. 3, pp. 172–174.
3. Physical Activity Guidelines for Americans, 2nd edition (health.gov)
4. Mazoochii, M, Fateminezhad, SE & Mazoochi, T, 2013, ‘Effects of Continuous and Interval Training on Different Fitness Parameters in Athletes’, World Applied Sciences Journal, vol. 28, no. 3, pp. 312-315.