Here are five ways to improve your aerobic endurance.

When you improve your aerobic capacity, you get more efficient at using oxygen during exercise.

This allows you to run, cycle, or swim — and do other aerobic activities — for longer, and often faster, with less fatigue.

There are also other health benefits, like improved heart strength and lung capacity.

In this article, I explain how you can improve your aerobic capacity. Whether you are a runner, cyclist, swimmer, triathlete, or just want to get more active, there’s something for you.

What you will learn:

  • What is aerobic capacity, and how to improve it 

  • How long it takes to improve your aerobic capacity

  • What activities and workouts to do to improve aerobic endurance

  • Common mistakes to avoid when doing aerobic exercise 

What is aerobic capacity?

Aerobic capacity refers to the maximum amount of oxygen your body can use during intense exercise. The higher your aerobic capacity, the longer you can sustain moderate-intense aerobic activity like running or cycling. 

This is often measured by VO2 Max — the volume of oxygen you consume per minute during peak exertion. 

The difference between a runner who can run a 15-minute 5k and a 20-minute 5k is usually a much greater aerobic capacity. It’s how efficiently the heart, lungs, and muscles work together to supply oxygen to your muscles while you exercise.

Can aerobic capacity be improved?

Yes, aerobic capacity can be improved. 

Using my running example, if you followed a structured training plan, you would likely increase your aerobic capacity. This is especially true if you are new to training or do not follow a structured plan (that includes workouts at intensities necessary to facilitate physiological adaptations).

Regular aerobic exercise — I will get into the specifics later in this post — improves the entire aerobic system, including:

  • Increased lung capacity and function: your lungs can hold more oxygen and send more to the muscles during exercise.

  • More mitochondria in the cells: you can produce more ATP, the main source of energy during aerobic exercise.

  • Increased heart size (mostly the left ventricle) becomes more efficient at delivering oxygenated blood to the muscles during exercise. 

How long does it take to improve aerobic capacity?

This depends on various factors, like:

  • How long have you been training 

  • Current fitness level

  • Training type

  • How often you plan to train

As a complete beginner, you are likely to see a more significant improvement in aerobic capacity compared to a seasoned athlete. Expect to see results in as little as 4-6 weeks.

The more you progress — this includes staying consistent with your training — the better the improvements. Expect to see significant improvements in aerobic capacity in 3-6 months.

For a more seasoned athlete, like a runner, you can still improve your aerobic capacity. Although, you won’t see as quick an improvement as a new runner or athlete.

Why is aerobic endurance important?

Aerobic endurance is important for several reasons.

If you’re an athlete, like a runner or a cyclist, improving aerobic endurance improves performance.

You can run or cycle longer at higher intensities, for example.

From a health perspective, aerobic endurance keeps the heart, lungs, metabolism, and circulatory system healthy. It allows you to reduce your risk of certain diseases and may also improve your mood and overall wellbeing.

Benefits of improving aerobic capacity

There are various reasons for improving aerobic capacity:

  • Improved endurance: you can go longer distances faster.

  • Increased VO2 Max: the muscles have more oxygen, which improves performance.

  • Improved heart strength and efficiency: lower resting heart rate and stronger heart (mainly the left ventricle), which delivers more oxygen to the muscles during exercise.

What activities increase aerobic capacity?

There are many ways to improve aerobic endurance like running, swimming, cycling, and even strength training. 

Below, I have provided various ways to improve aerobic capacity. Some activities are more specific to certain sports, like running, but all of these activities can be applied to improve aerobic endurance and total aerobic capacity.

Zone 2 training 

Zone 2 training is low-intensity aerobic exercise. It’s usually done at 60-70% of your maximum heart rate (MHR).

If you don’t have a heart rate monitor, aim for an effort where you can comfortably hold a conversation.

If you feel like you’re going too slow, then you are probably not going slow enough.

You can get many benefits from zone 2 training, including strengthening the heart. If you’re a runner, zone 2 should make up most of your weekly training, usually easy runs with one long run a week.

Tempo runs 

Coach Dr. Jack Daniels, in his book, Daniels' Running Formula, describes a tempo run as a steady run that usually lasts about 20 minutes in duration. These runs are good for building confidence when running at a fairly demanding pace.

Tempo runs will also improve aerobic capacity by improving your cardiovascular system's ability to deliver oxygen to the working muscles. This is because you’re working at a much harder effort than an easy run, for example.

Interval training 

Interval training is done close to your VO2 Max. It’s harder than a tempo run, and you cannot sustain this effort for very long.  

An example interval training session would be 5x2 minutes of hard running with 1-minute jog recovery between intervals. Your heart rate should be very high during the intervals, say 90 to 95% MHR.

Use the jog or walk breaks to catch your breath and prepare for the next interval.

Training at — or close to — your VO2 Max pushes the cardiovascular and muscular systems to the upper limits, allowing for aerobic adaptations.

Strength training 

When people think of improving endurance, the last activity they think of is typically strength training. 

However, research shows that resistance training, when added to an athlete’s training program — in trained and untrained individuals — improves short and long-term endurance capacity.

A good starting place is to include 1-2 resistance training sessions per week into your routine.

Some exercises you may want to add to your training include:

  • Squats or box squats

  • Step-ups 

  • Single leg RDLs

  • Monster walks or banded side steps 

  • Lunges

  • Lower back extensions 

  • Single-leg leg press 

  • Swiss ball hamstring curls

  • Split squats

  • Planks 

Regular strength training will also reduce your injury risk and improve your running. 

Fartlek runs 

The word “fartlek” is Swedish for “speed play.”

Fartlek runs are a type of unstructured speed session. Unlike a structured interval session, where you may run hard for 3 minutes and rest for 2 minutes, fartlek sessions have very little structure.

For example, you may sprint to the nearest car, jog to the mailbox, run fast to the yellow car, and so on. 

Fartlek sessions increase your heart rate and usually involve high-intensity running with short rest breaks. 

These Fartlek sessions improve aerobic capacity. The bursts of high-intensity effort lead to various physiological adaptations like improved VO2 Max, strengthened left ventricle of the heart, and improved lactate threshold — this helps delay fatigue.

Mistakes to avoid when improving aerobic capacity

Often, doing too much can be a hindrance. Whether that's too much training — known as overtraining — or too much of one session too often.

Here are two of the most common mistakes people make when trying to improve their aerobic capacity.

Overtraining and a lack of recovery

One of the biggest mistakes people make when wanting to improve aerobic capacity is doing too much too soon.

If you currently don’t workout, diving in the deep end and trying a tempo run, interval training, and doing a strength workout 1-2 times a week is not a good idea.

Take it slow, listen to your body, and give yourself plenty of time to recover between sessions.

Ignoring workout variety

If you only do one type of training, for example, zone 2 running or cycling, you limit your aerobic development.

And while zone 2 training is fantastic, you should also look to include sessions like tempo runs, interval sessions and fartlek runs. You want to challenge your aerobic and cardiovascular system in numerous ways to get the best adaptations. 

By all means build a solid base with zone 2, then sprinkle in more intense and structured speed sessions to push your aerobic capacity to the next level.

Key takeaways

  • Aerobic capacity is the maximum amount of oxygen your body can use during exercise

  • Regular aerobic exercise increases lung capacity, heart strength and efficiency, and mitochondrial density and delivers more oxygen to the muscles 

  • If you're a new runner or cyclist, expect to see aerobic improvements in 4-6 weeks and 3-6 months for significant gains

  • Add high-intensity sessions like tempo and fartlek runs and interval training to challenge the upper limit of your aerobic capacity

  • Strength training 1-2 times a week will improve muscular strength and aerobic endurance and increase injury resistance

  • Add a variety of aerobic workouts to best improve aerobic endurance

  • Avoid overtraining and prioritise rest, especially when starting a new training program