A Guide to Fitness Training for Team Sport Athletes

Written by Dr Craig Harrison

Science shows that game-changing moments in team sport typically involve high-speed actions. It’s why fitter athletes, who are more capable of repeating these throughout an entire game, are more likely to have an impact. So regardless of how you like it, fitness training is something you just can’t avoid. 


But it’s also easy to get wrong, leaving you tired, overtrained and at a higher risk of getting an injury. So let’s take a dive into aerobic fitness training and discuss what to focus on to get it right.

Where Does Energy Comes From?

The ability to repeat high-speed efforts throughout a game requires a constant supply of energy to fuel muscle contraction. Muscle contraction is powered by adenosine triphosphate (ATP). Like a bank that stores money, ATP stores energy so it can be used immediately to fuel exercise. The problem is, there’s only enough ATP to last for about 3 seconds of high-speed action. After that, you need to start making more.

The Creatine Phosphate Energy System

Muscle cells also contain a high-energy compound called creatine phosphate (CP), which is broken down to make more ATP quickly. This process happens very quickly and provides enough energy for about 8-10 seconds of high-speed actions.

The Glycolytic Energy System

Another way muscle cells make ATP is by breaking down glycogen, which is stored in the muscles from the carbohydrates we eat. This process generates energy slower than using CP but lasts longer (about 90 seconds).

Both the CP and glycolytic energy systems produce ATP relatively quickly to fuel high-speed actions in team sport. However, they are anaerobic energy systems (i.e., they don’t require oxygen) and produce byproducts in the muscles (e.g., lactic acid) that build up and cause fatigue (the burning feeling you get in your legs when you run up a steep hill quickly).

The Aerobic Energy System

A muscle cell can also generate ATP by breaking down glycogen with oxygen. When oxygen is present inside the cell, a process called aerobic respiration takes place, which can supply energy to the muscles for several hours. However, this system is slower to generate energy than the anaerobic systems described above.

Oxygen Delivery

When you breathe in, air travels down your windpipe (trachea) and into your lungs. The oxygen in the air then passes across a thin lining of air sacs in your lungs, called alveoli, into the bloodstream and is then transported around the body to the working muscles.

This process is critical because oxygen replenishes the ATP stores in your muscles after every high-speed action, refueling your anaerobic energy systems. What this means is that the fitter you are, the more high-speed actions you can repeat during a game or hard training session.

The hero of oxygen delivery is your heart. A bigger, more powerful heart can pump a greater amount of oxygen-rich blood to your muscles each time it beats. When the oxygen arrives at a muscle it is extracted from the bloodstream and used to generate ATP. The fitter you are, the more efficient this process happens, too.

Oh, oxygen also fuels the brain, which helps you maintain concentration when you get tired.

Building Your Aerobic Fitness

Optimising your aerobic fitness requires training your entire cardiovascular system. This includes your heart, lungs and blood vessels as well as the energy-generating capacities of your muscle cells. A great way to do this is by using a variety of training types.

Small-Sided Games

It’s likely that your coach includes small-sided games in your team training sessions. These are not only great for developing the technical and tactical skills of your sport, they also do a great job at improving your aerobic fitness.


In a study I conducted for my PhD1, we tested how well small-sided games work for training aerobic fitness in young team sport athletes. The results showed that 3 versus 3 games lasting up to 24 minutes, completed twice a week for 8 weeks, can significantly improve performance on an intermittent high-intensity running test. This is pretty cool considering you get to increase your fitness while also playing the game you love!

High-Intensity Interval Training

As the name suggests, high intensity interval training, or HIIT, involves repeated bouts of high-intensity exercise interspersed by short periods of recovery. HIIT is a great way to develop aerobic fitness quickly. However, maintaining a high enough intensity throughout each work period is a challenge.


  • Warm-up: 5 min movement snacking + 5 min jog
  • Intervals: 4 min running @ max effort followed by 3 minutes of jogging – repeat x 3-4
  • Cool down: 10-15 min sport-specific skill work

Steady-State Training

Steady-state training, also known as tempo training, involves a continuous effort at a speed you can maintain for a moderate amount of time without slowing down. This type of training is a great way to get used to resisting the byproducts of anaerobic exercise that build up in your muscles and cause fatigue.



  • Warm-up: 5 min movement snacking + 5 min jog
  • Steady-state effort: 15-30 min of continuous running (or biking) @ the same pace
  • Cool down: 10-15 min sport-specific skill work

Low-Intensity Continuous Training

Low-intensity, continuous training is exactly as the name suggests – low-intensity and continuous. It’s important to include because of how it trains your muscle cells to better utilise oxygen to generate ATP.


The key, however, is not going too hard, as the session will quickly morph into a steady-state one. To get it right, consider low-intensity as a pace you can comfortably maintain a conversation at.



  • Warm-up: 5 min movement snacking
  • Steady-state effort: 20-60 min of continuous running (or biking) @ low-intensity
  • Cool down: 10-15 min sport-specific skill work

Give these aerobic fitness workouts a try and see if they work for you. If you’re looking for a ready-made plan, flick me a message and let’s chat.

If you liked this post, don’t forget to share so that others can find it, too.


  1. Harrison CB, Kinugasa T, Gill N, Kilding AE. (2015). Aerobic Fitness for Young Athletes: Combining Game-based and High-intensity Interval Training. International Journal of Sports Medicine, 36(11), 929-34. 
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