Improving Anaerobic Ability: High Intensity Interval Training

Runner launching off the blocks into full sprint.

What is HIIT? HIIT is high-intensity interval training, which means that you do hard intervals with a short rest, then go at it again. This leads to having many shorter runs in one day – rather than 1x5K, it could be 12x400m. High-intensity interval training can be incredibly strenuous on the body, which is why many people use it to strength train and burn calories.

It’s not only used for weight-loss however, this type of training works very well with running too. Marathon runners don’t benefit as much from HIIT as others, since marathons are long distance rather than short, hard bursts of speed. Runners looking to improve their 5k or lower distance will benefit greatly from this type of workout. However, before you jump onto the bandwagon you need to know a few things first.

High-intensity interval training:

There is a reason why it is called “high intensity” interval training. This puts your body to its limits and pushes all types of your muscle fibers – particularly your fast-twitch muscles. Your speed will greatly improve and you can put more power into each step forward. Developing more power always comes at a cost, though – your body will be sore the next day and it’s best to rest, cross-train, or take a recovery run the day after.

An interval is supposed to be a relatively short, intense effort. With normal intervals, you need to give adequate time to rest so that you can do the next interval at the same effort without failing. Regular intervals are best done with a few minutes of rest, so that your energy levels are restored and you can go straight back into tearing muscles and developing your cardiovascular system. However, in high-intensity interval training, you give yourself less time to recover than the amount of time you put the effort in. The common ratio is 2:1 – so if you run 400m intervals at 1:30 per, you should give yourself 0:45 of rest.

Because of the very short recovery time, you simply do not have enough time to fully rest before the next interval. It becomes increasing hard with each interval to continue, both physically and mentally. Due to how taxing it is, sessions are generally only 20-30 minutes long, not including warm-up.

Extra notes:

Starting a training plan with HIIT requires some preparation. Jumping straight into interval training can increase your risk of injury, so slowly increasing the amount of intervals until you reach the training level you want is far better. Taking your time is well worth the wait, as an injury could set you back for days (or even weeks!).

HIIT can easily help you improve, but switching all of your training over to HIIT workouts will actually be detrimental to your performance. Instead, add a mix of easy days and hard days. The hard days could be HIIT. It’s recommended to have no more than 3 hard days to get maximum gain from your training. In fact, some coaches recommend only one day of interval training per week due to the high stress! The rest of the week should be rest or easy days. HIIT is brilliant for developing power and speed, but easy days are needed to help your aerobic ability improve without destroying your muscles.

Choosing the distance:

For track athletes: This is some of the best quality training for you to undergo. Seriously.

On the track, speed is a very important factor. Even with a strong middle and finish, a slow start can impact the entire race. High-intensity interval training develops your speed potential, and allows you to push off from the start with great power. When training for the track, you almost never train at an interval the same length, except for 200m and below events. Even then, intervals will usually be between 50m and 150m of length.

For 200m and below, a lot of focus will be put on a strong start and maintaining. By setting intervals of 50m, it trains the athlete, you, to push hard and develop the power-speed you need to beat your opponents by those precious fractions of a second. 100m-150m are used to help train the athlete to maintain for the last 50m-100m along with a good kick in the beginning.

Every track athlete should run very intense 200m intervals at least once in their training cycle to work the fast-twitch muscle fibers hard and leave them calling more muscle fibers at the last few strides.

For 5k runners: If your goal is to bust your 5k PB, 200m-400m intervals at a pace 10s-20s faster than your 5k race pace can help. Doing 6-8 of these with 1-2 minutes of rest in between each can exponentially increase your speed-endurance over the long term. Another interval is the 800m, however instead of bumping 30s-40s off of your last 5k pace, it would be best to only bump 5s-10s as otherwise it won’t help performance as much due to being too harsh on the body.


  • 10x400m @ 5k RP-0:10 w/ 1:00 rest.
  • 12x200m @ 800m RP-0:04 w/ 0:18 rest.
  • 8x50m @ 95% Effort w/ 0:05 rest.

Of course, these are only examples. You could mix them up to suit your goal. If you want to be a faster sprinter, intervals of 100m-200m would be better suited. If you’re focusing on longer distances, 400m-800m normal intervals would be optimal. High-intensity interval training can be used to develop both aerobic and anaerobic ability, but it heavily sways towards your anaerobic ability. Keep this in mind when training for your events.

Run and realize the benefits:

High-intensity interval training is tough. It’s very hard to make comfortable, but it does lead to many improvements to the anaerobic system.

Because of the very short recovery time, you simply do not have enough time to fully rest before the next interval. It becomes increasing hard with each interval to continue, both physically and mentally.

Both a mental and physical challenge, this type of training should not be taken lightly. It is recommended however, due to how effective it is. Mental training and developing willpower is one of the improvements that come from this training. Your willpower can make or break the result of your race – you could smash a PB, or end in a DNF.

Here are the benefits:

  • Raises mitochondria numbers and size.
  • Improves anaerobic efficiency.
  • Strengthens the intermediate and fast-twitch leg muscles.
  • Increases willpower and mental strength.
  • Increases metabolism.
  • Burns through fat.
  • Improves insulin activity and sensitivity.
  • Increases VO2 max.

HIIT is a fantastic way to improve your running. Implementing this into your future plans can help you smash your old PB’s and significantly quicken your pace. Keep it in moderation, and you will do great things. Good luck in your training!

Image of sprinter courtesy of Roman Boed under the Creative Commons Attribution 2.0 Generic license. Resized.

Caleb Thompson is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to,, and other Amazon stores worldwide.

Do you want to become a running champion?

Of course you do! Let us help you - we'll give you the latest up-to-date info, based on science-proven facts. All we need is an email.