Endurance and cardiovascular training

Endurance

Endurance training is considered a training form to increase or maintain performance and the body’s ability to work at high intensity for an extended period. General good endurance is important for maintaining everyday activities and for performance. Regardless of age and gender, endurance plays a vital role in health and daily activities, such as doing household chores or playing with children. You train endurance when you engage in an activity for a long time, leading to a significant increase in energy expenditure. This could be a leisurely bike ride, a jog, or a good walk. What is considered "long" depends on your starting point. As a beginner, you will see good effects from almost any activity. Previously, it was believed that the activity had to have a continuous duration of at least 10 minutes, but we now know that activities of shorter duration can also benefit beginners.

Cardiovascular training

Cardiovascular training, or maximal oxygen uptake, is often defined as the body's maximum ability to take in and utilize oxygen. You may have heard that a high maximal oxygen uptake is essential for elite athletes in middle and long-distance running or cross-country skiing, but good maximal oxygen uptake is also important for everyday people. Maximal oxygen uptake is associated with the risk of premature death; that is, the higher the oxygen uptake, the lower the risk of early death.

Cardiovascular capacity is primarily limited by the cardiovascular system, which includes the heart (cardiovascular) and blood vessels (vascular). To improve cardiovascular fitness, we must therefore train the heart muscle. Cardiovascular training strengthens the heart, lungs, and blood vessels, allowing blood to flow better to the parts of the body that need it, such as our muscles during exercise. This can lead to increased secretion of endorphins (the body’s natural morphine that has pain-relieving effects and provides a feeling of euphoria/happiness) and can enhance overall well-being. Cardiovascular training can also help prevent stress and depression.

You can train your cardiovascular fitness by continuously taxing the heart for a certain period. To improve cardiovascular capacity, you must positively stress the heart, meaning that we intentionally increase heart rate through various physical activities. To elevate your pulse, it’s effective to use large muscle groups, such as by running, cycling, or rowing. It's also important to maintain a relatively high intensity, train regularly, and have a certain duration for your workouts relative to your starting point. If you are relatively untrained, you will gain significant health benefits from a short workout, so it's essential to remember that anything is better than nothing!

Low intensity feels quite easy. You can speak in longer sentences without too much effort. You don’t sweat much, but your heart rate is slightly higher than at rest.

Moderate intensity feels a bit more demanding, yet still quite comfortable. You can say a few short sentences and may sweat a little. Your heart rate is faster than at low intensity.

High intensity is strenuous. You can only say a few words and breathe heavily. You sweat a fair amount and have a high heart rate.

When you start exercising, it may feel a bit strange and uncomfortable. You will notice your heart beating faster, your breathing quickening, and that you are sweating. This is perfectly normal and not dangerous. As you continue to train, you will get used to the sensation. Even highly trained athletes sweat and gasp for breath.

Regardless of how slowly you jog at the beginning, it will likely feel like high intensity. For many, it is almost impossible to jog at low or moderate intensity in the beginning. This is completely okay! It might be a good idea to choose another form of activity that is considered "low intensity" at first, such as cycling, using a cross-trainer, or brisk walking. As a beginner, you will quickly become fitter!

Borg's scale of perceived exertion

If you don’t have or don’t want to use a heart rate monitor during your workouts, you can use Borg's scale of perceived exertion. Borg's scale is an alternative method to track and manage the intensity of your training. With this method, you can gradually assess the intensity based on how you feel. Being able to speak normally (talk test), gasping for breath, or experiencing stiff muscles are examples of how you perceive your workout.

The scale ranges from 6 to 20, where 6 corresponds to rest and 20 corresponds to maximal effort.

The scale is intended for endurance training and is used to find your subjectively perceived level of exertion.

Olympiatoppen's intensity scale

Olympiatoppen has developed an intensity scale that consists of 8 intensity zones. The intensity zones are defined based on several factors, such as heart rate, perceived exertion (RPE), pulse, and respiratory rate. Many people use a heart rate monitor if they want to train based on pulse zones. Most fitness trackers use a 5-part scale. These zones are useful for athletes or fitness enthusiasts who want to train a bit more advanced.

This scale is not necessary for beginners, but many fitness enthusiasts and athletes train so much that they need certain parameters to ensure they are not overtraining or pushing themselves too hard. In such cases, an intensity scale can be very helpful.

Intensity Zones 6-8 are primarily used in sprint and explosive training.

For an athlete training over 1000 hours a year, it is essential to closely monitor the overall training load. In such cases, this scale and the parameters relevant to the specific sport can be employed. RPE is a scale from 1-10 that indicates how hard the training feels to the participant. Another way to manage training intensity is to use heart rate. Typically, training is divided into zones based on a percentage of maximum heart rate. Additionally, many athletes use something called lactate to measure intensity. Lactate is produced in the muscles when they do not receive enough oxygen. A lactate test, taken through capillary blood from the fingertip, provides information about the training load: the higher the load, the more lactate is produced. You may have experienced muscle stiffness after very intense training. This is not dangerous for a fitness enthusiast or "the average person" who trains a few times a week, but for an athlete who has more than one training session a day, it can affect subsequent workouts.

The final column of the intensity scale is beneficial for fitness enthusiasts who are not overly concerned with lactate and heart rate. Ventilation is a useful measure of intensity when training for endurance and stamina.

Duration

For training to be effective, it must also have a certain duration. How long you train depends on your starting point and your training goals.

A general rule of thumb is that the higher the intensity, the shorter the training session can be. However, it’s still necessary to train for a certain amount of time so that the heart is continuously challenged, allowing it to adapt and become "stronger." This is the core principle of cardiovascular training. If you're training with high intensity, such as interval training, 10-20 minutes (for beginners) or 20-30 minutes (for experienced individuals) after warming up can be sufficient. If you’re doing a more relaxed workout, like a bike ride or an easy jog, you can train for a longer period. Start with a duration that feels suitably challenging for you.

If you're a beginner and find it hard enough to walk for 10 minutes, start with that. Next time, you might manage 11 or 12 minutes! Even short bursts of physical activity have been shown to have significant health benefits if you're not very active beforehand.

Frequency

Training should be done with a certain frequency to have an effect. Find a frequency that fits your routine and lifestyle. It can be helpful to schedule regular sessions with a friend to make it easier for yourself.

If you're a beginner, start small! Two workouts a week are much better than none!

As a recreational athlete, it's not necessary to do cardio and endurance training every day. Remember that recovery is crucial for making good progress! You can vary the types of training throughout the week, for example, two interval sessions and one long, easy session, or two easy runs and one interval session.

Finally, it’s essential to remember that the best training is the one you can do consistently and that motivates you to keep going!

Warm-up

If you plan to train at higher intensities, it's important to start with a proper warm-up. Ideally, this should be 5-15 minutes of the same activity at a low to moderate intensity. Gradually increase the intensity during the warm-up by moving faster, up to the pace you'll be training at.

For very intense workouts, it's recommended to do a few acceleration sprints of 60-100 meters. Start slowly and increase speed to a pace slightly faster than your interval pace. Be sure to rest well between sprints.

Cool-down

After high-intensity training, it's recommended to spend some time cooling down. This can be 5-10 minutes of low-intensity activity, such as the one you've been doing, or another activity like running or cycling. Cooling down is a pleasant way to finish a high-intensity session, giving you a chance to calm down before moving on with your day.

In the past, it was believed that cooling down was essential for improving recovery and reducing muscle soreness, but research now shows that it doesn't significantly impact these factors. So, if you're short on time and need to choose between warming up and cooling down, prioritize the warm-up.

Beginner

Low intensity

For a low-intensity workout, you should exercise continuously at a comfortable pace. This corresponds to 6-13 on the Borg scale. Choose a duration based on your current fitness level. If you're untrained or inexperienced, 10 minutes might be enough to start with. Next time, try to push a little longer.

Suggested full low-intensity session for beginners (Link)

Moderate intensity

For moderate-intensity training, you can either work continuously or break the workout into intervals. Intervals involve alternating between effort and rest. Choose a pace that makes you breathe a bit harder but still able to speak in short sentences. Aim for 15-40 minutes of continuous work, or split the time into shorter intervals. Since the intensity is lower than high-intensity workouts, intervals can be a bit longer.

Example intervals:

- 2 rounds of 8 minutes work, rest for 2-3 minutes

- 2-3 rounds of 5 minutes work, rest for 1-2 minutes

- 4-8 rounds of 2 minutes work, rest for 1 minute

Practically, this means you work hard (Borg scale = 14-16) for a set time (e.g., 5 minutes), rest briefly (e.g., move at a slow pace for 1-2 minutes), and repeat for a set number of rounds (e.g., 3 rounds). In this example, the session is called 3x5 min intervals.

Rest intervals can range from 45 seconds to 3 minutes. A good rule of thumb is to rest for ½ or ⅓ of the work time, but there’s rarely a need for more than 3 minutes of rest.

Suggested full moderate-intensity interval workout for beginners (Link)

High intensity

When training at high intensity, you should work hard enough to breathe heavily, only able to say a couple of words at a time. This should feel like 16 or higher (hard) on the Borg scale. You don't need to work to complete exhaustion, but it should feel tough enough that you can't continue much longer when it's time to rest. Interval training, where you alternate between periods of hard effort and rest, is a great way to increase intensity.

Example intervals:

- Pyramid intervals: 1-2-3-3-2-1 minutes work, rest half the work time

- 3-4 rounds of 4 minutes work, 2 minutes rest (4x4 min)

- 10-20 rounds of 30 seconds work, 30 seconds rest (10-20x30/30)

- Hill intervals: run uphill a set number of times, jogging slowly downhill during the rest.

Suggested full high-intensity interval workout for beginners (Link)

Intermediate

Low intensity

If you are going to train a session with low intensity, you should engage in continuous work at a pace that feels comfortable. This type of session corresponds to intensity zones 1 or 2 and 6-13 on the Borg scale. The length of the session depends on your level and fitness. A low-intensity training session can range from 30 minutes to several hours.

Suggestions for a complete low-intensity long session for intermediates (Link)

Moderate intensity

If you are going to train a session with moderate intensity, you can either do continuous work or break it up into intervals. The length of a moderate-intensity session typically ranges between 20 and 45 minutes of continuous work or intervals with slightly longer work periods. This corresponds to intensity zone 3 or 14-15 on the Borg scale.

Examples of Sessions:

- Intervals: 2-3 x 10 min, rest 2-3 min

- Intervals: 4-6 x 5 min, rest 1-2 min

- Intervals: 4-5 x 6 min, rest 2 min

- 20-30 minutes of continuous moderate effort. Remember to warm up first!

Suggestions for a complete interval session with moderate Intensity for intermediates (Link)

High intensity

When training at high intensity, it is a good idea to break the session into intervals so that you can maintain high intensity for longer overall. This corresponds to intensity zones 4 and 5 and should feel like 16 or higher on the Borg scale. You do not need to work to complete exhaustion (zone 5), but make sure to maintain such a high intensity throughout the interval period that you feel the following rest is necessary.

Examples of Intervals:

- Pyramid: 1-2-3-4-(+)-4-3-2-1 min of work, rest half the work time

- 4-6 x 4 min, rest 2 min

- 20-40 x 45 sec, rest 15 sec. If you want, you can have a longer series break (1-2 min) after every 10 repetitions.

Suggestions for a complete interval session with high intensity for intermediates (Link)

Advanced

Low intensity

If you are going to train at a low intensity, you should engage in continuous work at a pace that feels easy, preferably in I-zone 1 or 2, or corresponding to 6-13 on the Borg scale. The duration of the training depends on the goal of the session. At low intensity, you can train anything from a short recovery session to a long workout lasting several hours.

Suggestions for a easy long distance session (Link)

Moderate intensity

If you are going to train at a moderate intensity, you can either train continuously or split it into intervals. The duration of a session with moderate intensity typically ranges from 20 to 45 minutes of continuous work or intervals with slightly longer work periods. This corresponds to I-zone 3 or 14-15 on the Borg scale.

Examples of sessions:

• Intervals: 3-5 x 10 min, rest 2-3 min

• Intervals: 8-10 x 4 min, rest 1 min

• Intervals: 6-10 x 1000 m, rest 1-2 min

• 20-45 min of continuous moderate effort.

Remember to warm up first!

Suggestions for a well-structured interval training session with moderate intensity for you at an advanced level (Link)

High intensity

High-intensity sessions should be divided into intervals so that you can maintain high intensity over a longer total duration. High intensity corresponds to I-zones 4 and 5 and should feel like 16 or higher on the Borg scale. You do not need to work completely to exhaustion, but make sure to maintain a high intensity throughout the interval so that you feel the rest is necessary.

Examples of intervals:

• Pyramid intervals: 1-2-3-4-5-5-4-3-2-1 min of work, rest 1-2 min

• 12-20 x 400 m, rest 1 min

• 6-8 x 4 min, rest 1-2 min

Suggestions for a well-structured interval training session with high intensity for you at an advanced level (Link)