Photo credit: Kim Nguyen
What is endurance?
Endurance is our ability to maintain a sustained level of intensity over time.
It can also refer to the rate at which intensity decreases as the duration of physical effort increases. The faster your relative intensity drops, the less endurance you have. Conversely, the less it drops, the greater your endurance.
Physical endurance involves three physiological factors:
- Muscular endurance, or our ability to recruit slow-twitch muscle fibers (type 1).
- Cardiorespiratory endurance, or the ability of our heart and lungs to supply the amount of oxygen we need to sustain effort.
- Mental endurance, or our ability to cope psychologically with the fatigue and pain caused by long-duration effort.
Endurance, aerobic, and anaerobic exercise
There are two main types of physical effort.
Anaerobic exercise is when you perform a short, explosive effort. Your muscles consume more energy than the oxygen available in your blood can provide. You give everything you have for less than two minutes, and your muscles start to burn. This is the kind of effort made by sprinters or weightlifters, for example. By training your anaerobic system, you improve your strength and power.
Aerobic exercise, on the other hand, is when you work with a constant and sufficient supply of oxygen. Oxygen allows the muscles to produce the energy they need by burning carbohydrates and fats. Aerobic effort is less intense, but more sustainable: this is the kind of effort involved in endurance.
VO2 max, max HR, MAS, MAP: how do you measure endurance?
Mitochondria are specialized structures found in our cells. Their role? To turn oxygen into energy.
The more effort we make, the more oxygen we need, and the more our heart and lungs are put to work. That is why athletes, especially those involved in endurance or middle-distance disciplines, pay such close attention to their heart and breathing rates.
What is VO2 max?
VO2 max is the maximum amount of oxygen the body can use during exercise. It is measured in milliliters per minute per kilogram of body weight. Your VO2 max is correlated with your MAP (maximum aerobic power). For runners, MAS (maximum aerobic speed) is the highest pace you can maintain aerobically.
If, during physical activity, you go beyond your VO2 max, you shift from aerobic effort to anaerobic effort. In other words, you move out of the endurance zone.
Most smartwatches provide a VO2 max estimate, but the value is only indicative. The only way to measure your VO2 max accurately is through an exercise stress test with a healthcare professional.
How do you calculate your MAS?
Maximum aerobic speed is easier to estimate. The half-Cooper test is easy to perform, especially if you have access to a track.
Run as fast as you can for six minutes. To calculate your MAS, simply divide the distance covered by 100. If you run 1,600 m in six minutes, your MAS is 16 km/h.
What is max HR?
Max HR is the highest rate at which your heart can beat. It mainly depends on your age. Knowing your heart rate helps determine your effort zone, which is calculated as a percentage of max HR. Training endurance will not increase your max HR. However, by strengthening your heart, you will gradually need to strain it less. Your resting heart rate will decrease, and you will be able to go farther and faster without your heart having to beat harder.
For activities that require sustained effort, it is generally recommended to work at around 70% of your max HR.
To estimate your max HR, you can use the Astrand method:
- For women: 226 − your age (for example, if you are 40 years old, your max HR is 226 − 40 = 186)
- For men: 220 − your age (if you are 30 years old, your max HR is 190)
Of course, these numbers are only estimates. If possible, an exercise stress test with professionals will provide much more accurate measurements.
What are the benefits of endurance sports?
The first advantage of endurance sports is how accessible they are: from walking to ultratrail or ultracycling, including adaptive sports, everyone can find a discipline that suits them. To get started, you do not need expensive equipment or heavy infrastructure: a pair of running shoes may be enough.
Endurance sports are especially beneficial for physical health. They reduce the risk of cardiovascular disease, diabetes, and certain cancers. They strengthen the heart and improve respiratory capacity, while also giving the immune system a boost. They contribute to muscle strengthening, improve bone health throughout the body, and are an excellent way to fight obesity and all its related conditions.
And that is not all: endurance sports also have a positive impact on mental health. Training releases endorphins and improves sleep quality, which, over time, can help reduce stress and anxiety. Working on your endurance also helps develop perseverance, resilience, and concentration: you strengthen not only your muscles and bones, but also your mind.
How can you improve your endurance?
The secret to endurance rests on three pillars: consistency, gradual progression, and recovery. That is the only way to gradually learn how to sustain effort.
Train consistently
To improve endurance, consistency is essential: it is better to train several times a week, even with short, low-intensity sessions, than to do a few big workouts here and there. Long breaks are not your friends. Every stop means starting again, and those are the moments when the risk of injury is highest.
Focus on gradual progression
Rome was not built in a day. Increase the duration and distance of your workouts little by little. At first, just a few extra minutes from one session to the next can be enough to get the process started. Trying to go too fast means risking injury and discouragement before reaching your goals.
Learn to go slow
Yes, you read that right. To improve endurance, especially in running, you need to learn to run... slowly. It may seem counterproductive, but at 70% of your max HR, you are training your aerobic base, and that helps you progress. During these easier sessions, you should be able to hold a conversation without difficulty.
Do interval training
Interval sessions are structured workouts made up of alternating phases. They combine high-intensity sequences with recovery periods. For beginners, this can simply mean alternating running and walking. As you improve, the goal is to increase the running intensity (in zone 4 or 5) and recover in zone 1 or 2. The purpose? To train the body to work at high intensity, increase VO2 max, and therefore improve MAS.
Recover to progress
Recovery is essential to limit fatigue,regenerate muscles,help them adapt and become stronger, and prevent injuries.
Active recovery (walking, yoga, easy cycling, or relaxed swimming), right after training, stimulates blood circulation and helps the body flush out toxins. You can combine it with self-massage to ease pain and stimulate cell oxygenation.
Passive recovery means complete rest: this is when the cells regenerate.
