Any movement that demands enough muscle will raise your heart rate. Keep the heart rate elevated for enough time, and you will develop cardiovascular endurance.
This requires less time than you may think though. Achieving cardiovascular endurance as efficiently as possible will develop the same general health and fitness changes as longer durations. This also brings other benefits such as saving time and addressing the anaerobic system as well.
Health
During cardio, the heart and lungs work to circulate a lot of blood. This blood supplies oxygen, nutrients, and removes waste products.
This process along with others that occur alongside it provide these benefits and more:
- Blood pressure decreases.
- The LDL to HDL cholesterol ratio improves.
- Fat gets used as energy more efficiently.
- Insulin needs decrease and better glucose tolerance develops.
- Blood flow improves.
- The lower back improves by allowing fluid to transfer in and out of the spine.
- Mental health improves.
Performance
While many activities can classify as cardio since the aerobic system works even at rest, specific exercise for it has unique value. Compared to lifting weights, it will raise the heart rate more so due to involving more muscles at once.
This allows these adaptations to develop at greater levels and separates itself from the benefits of lifting:
- The strength of your heart and capillaries increase.
You can achieve a higher cardiac output with fewer heartbeats. Oxygen travels throughout the body more smoothly. You get rid of the by-products from fatigue faster.
Your heart rate at rest lowers, which eases the daily burden for your heart.
- Chemical reactions occur faster.
- Slow-twitch muscle fibers produce more force and last longer.
- You gain more mitochondria.
These are the workhorses for all of your cells.
- You arrive at the blood lactate threshold later.
This means you can remove lactate from the blood faster. Lactic acid causes the burning sensation you feel in muscles worked intensely for longer than a minute. A capable cardiovascular system can sustain hard exercise for longer before this acid drops your performance.
- You recover from all exercise faster.
The aerobic system works at all times and therefore affects the recovery from all forms of exercise.
- VO2 max or maximal oxygen uptake improves.
This factor is the single best measurement for aerobic fitness.
Conflicts
Some research indicates that a competition for strength and endurance exists. For example, the intermediate fast-twitch muscle fibers can take on characteristics of both strength and endurance. Perhaps they may lean one way or the other depending on what kind of exercise dominates for the trainee.
I believe that strength and endurance can each develop at the best rates together. Improving both does increase the demands on the body though. Success in one makes the other feel tougher due to different reasons than suspected. Practical reasons such as a higher bodyweight allowing for more strength but making longer durations feel more exhausting better explain why a conflict seems to take place.
This likely does not occur due to an incompatibility. Adaptations for strength versus endurance should occur mostly in different regions and systems of the body. If some interference does occur, this can is probably offset by the benefits of a well-rounded body.
Based on your genetics, you still may be more likely to succeed in one than the other.
Mode
Choose a mode you enjoy and can perform safely. I suggest avoiding cardio machines and focusing on free weight exercises. The best and safest choices, if done correctly, are resisted sprinting, stairclimbing, and jumping. You can vary your choice if desired but variety for its own sake serves no purpose.
If training for a sport, you must practice it most of the time since some adaptations occur locally in the muscles. For example, you may develop your VO2 max from sprinting but lack the muscular endurance to deal with lactate in the upper body muscles used for swimming.
Weight-bearing exercise can carry some risks for injury. This includes all the choices mentioned. This stimulates the connective tissue to grow though. Make sure to avoid overtraining and rest as needed.
Type
Cardiovascular endurance divides into two categories: aerobic and anaerobic. Each draws energy from a different process. Aerobic endurance relies mostly on the oxidative system. Anaerobic endurance relies mostly on the glycolytic system.
There are three ways to improve cardiovascular endurance:
- Continuous Low Intensity
- Continuous High Intensity
- Intervals
Continuous Low and High Intensity
Continuous low intensity training relies on long durations. Traditional steady state aerobic exercise required between 60-80% of your maximal heart rate sustained for at least several times a week. You performed this at least 15-20 minutes and often far longer.
This seems needed only for those in long-distance events to get the specific adaptations. It otherwise inefficiently uses your time. You also risk overuse injuries and the wasting away of lean tissue for energy.
It does provide a possible option for less healthy individuals. They may not be able to sustain the high intensity for more efficient methods.
Low intensity training allows for active rest. This reduces stress and boosts recovery while not overburdening the body. Walking is the best activity for this and can be done between more intense sessions.
Some experts state that longer durations lead to more fat burning. This is correct but misleading. Although lower intensities do rely more so on fat, the overall caloric balance of the person stays the same. This surplus then gets stored as fat anyway.
Continuous high intensity training works more efficiently. It still may lack the anaerobic benefits possible with intervals since a high spikes in performance does not occur during continuous exercise. An example of high intensity continuous exercise could include running a mile or for five minutes as fast as possible.
Intervals
The aerobic system plays a large role with as little as 2 minutes of exercise. By choosing a time frame of 3-5 minutes, you can allow both the aerobic and anaerobic systems to contribute. Intervals achieve this by alternating bouts of high intensity with periods of total rest or much lower intensity.
VO2 max represents our maximal aerobic power. It serves as a reproducible measure of the body’s cardio capabilities. Consider that studies show you can get the same improvement in VO2 max if you focus on intervals versus much longer exercise.
Intervals do burn fewer calories. Losing weight though has much more to do with eating less calories than with more exercise. Too much exercise will remove lean tissue which keeps the metabolism elevated and also allows you to look and perform your best.
Seek Efficiency for Improving Cardiovascular Endurance
Science is the belief in the ignorance of the experts.
– Richard Feynman
Cardiovascular endurance does rely on some prolonged exercise. Interval training efficiently develops both the aerobic and anaerobic endurance though. This is the best option for most trainees.
Instead of trying to achieve aerobic fitness by adding more time, add more work for the least amount of time needed. Increase the pace or resistance but keep time constant. This applies the sound principle of progressive overload to develop cardiovascular endurance.