Everything You Need to Know About Cardiovascular Exercise -

Kaitlin Little

Most people already know that cardiovascular exercise is important for our health. It helps us lose weight, keeps our heart strong, and protects against several chronic diseases. Although, before you start an exercise program, you may want to learn more about ‘cardio’ and what you can do to maximize your efforts.

What is Cardiovascular Exercise?

Cardiovascular exercise refers to activities that recruit large muscle groups and raise your heart and breathing rate. Cardiovascular exercise can be considered either aerobic or anaerobic. However, generally speaking when people say cardiovascular exercise or “cardio” they are referring to aerobic exercise.

Aerobic exercise involves continuous, rhythmic movements that are performed for a prolonged period of time. Typical examples of aerobic exercise include jogging, swimming, hiking, cycling, or rowing.

Anaerobic exercise, on the other hand, involves quick bursts of energy that are performed at maximum effort and can only be sustained for a short period of time. For example, sprinting long distances (over 200 meters) or rapidly cycling uphill is anaerobic exercise.

Aerobic vs. Anaerobic

The key difference between the two is that aerobic exercise is performed with oxygen, while anaerobic exercise is without oxygen. During aerobic exercise, blood supplies oxygen to the contracting muscles which allow fuels (like carbohydrates and fats) to be broken down efficiently and used for energy.

During anaerobic exercise, muscle contraction is so rapid that there is not enough time to deliver oxygen. As a result, fuels already present in the muscles are broken down without oxygen, which leads to the formation of by-products such as lactic acid.

If you’ve ever sprinted up a hill or performed squats to exhaustion, you’ve probably experienced a burning sensation in your legs. That’s the buildup of lactic acid in your muscles and one of the key reasons we cannot sustain anaerobic exercise for periods longer than two minutes.

What’s Better for Cardiovascular Health?

Both anaerobic and aerobic exercise improve overall health and provide cardiovascular benefits. However, aerobic exercise is generally considered the best for improving cardiovascular endurance, sometimes called cardiorespiratory endurance. This refers to the ability of the heart, lungs and blood vessels to supply oxygen during sustained aerobic activity. Individuals who engage in regular aerobic exercise have a lower risk of cardiovascular disease, type 2 diabetes, depression, and certain cancers. [1]

After 6 months of regular aerobic training, previously sedentary individuals can reduce their resting heart rate by between 5-20 beats per minute, lower their resting blood pressure, enhance the strength of their cardiac muscle, and increase stroke volume by 20% (i.e. the amount of blood the heart pumps out with each beat). Studies show that these improvements in cardiovascular fitness are associated with a longer life expectancy. [2]

FITT Principles of Cardiovascular Exercise

When prescribing cardiovascular exercise, exercise professionals often use the FITT principle to help reach your fitness goals. FITT stands for the frequency, intensity, time and type of exercise.

Frequency – How Often?

Frequency refers to the number of times you engage in exercise per week. For maximum cardiovascular benefits, the American College of Sports Medicine (ACSM) recommends participating in moderate-intensity aerobic activity at least five days a week, or vigorous-intensity aerobic exercise on three days of the week. [3]

You may gain additional benefits from engaging in exercise more frequently, but three to five days per week is the recommended range for general fitness.

Intensity – How Hard?

We’ve mentioned the terms moderate-intensity and vigorous-intensity, which sounds great on paper. But, what do those intensities actually mean in the real world?

Intensity has to do with how hard you are working and it can be broadly classified into three groups: low-intensity, moderate-intensity, and vigorous-intensity.

One of the most accurate ways to measure exercise intensity is as a percentage of your maximum heart rate (HRmax). You can estimate your HRmax by subtracting your age from 220. If you’re 30-years-old, your HRmax would be approximately 190 beats per minute. But this is a rough estimate, and there is a lot of individual variation.

The easiest way to monitor your heart rate during exercise is with a heart rate monitor, such as a chest strap or wrist band. However, you can also estimate your heart rate the old-fashioned way—by counting your pulse for 15 seconds and multiplying that number by four. You can use either your radial pulse on the inside of your wrist or your carotid artery pulse in your neck. As you can imagine, this method is not always practical.

A much more straightforward way to measure your intensity while exercising is the talk test. Essentially, the harder you exercise, the more breathless you become, and the harder it is to talk.

Low-intensity exercise slightly raises your heart rate to 40-50% of your HRmax. At this intensity, you can talk and sing easily without running out of breath. Examples include slow walking, tai chi, and beginner’s yoga. Incidental exercise, such as carrying groceries, washing the dishes, and cooking also counts towards low-intensity activity.

Moderate-intensity exercise accelerates your heart rate to between 50-70% of your HRmax. Examples include brisk walking, slow cycling, lap swimming, or strenuous yoga. In terms of the talk test, you can comfortably hold a conversation, but you can’t sing without running out of breath.

Vigorous-intensity exercise requires a large amount of effort and is performed at 70-85% of your HRmax. It involves strenuous exercises such as running, circuit training, fast cycling, and competitive sports. At this intensity, you won’t be able to say more than one or two words without gasping for breath.

Overall, the aim is to perform 150 to 300 minutes of moderate-intensity, or 75 to 150 minutes of vigorous-intensity aerobic exercise per week.

Time – How Long?

Time refers to the duration of each session. To achieve cardiovascular benefits, the American College of Sports Medicine (ACS) recommends sustaining each session for at least 30 minutes at moderate-intensity, or at least 20 minutes at vigorous-intensity. Longer sessions of up to 60 minutes are associated with the greatest gains in cardiovascular health. At durations beyond 60 minutes, the benefits begin to level off and your risk of injury increases. [4]

However, the Physical Activity Guidelines for Americans suggests that accumulating shorter bouts of even 5 to 10 minutes still counts towards meeting the overall guidelines. If you’re new to exercise, this is a great place to start because you’re still going to see benefits! In one study accumulating multiple short bouts of low-to-moderate exercise (≤ 6 min) significantly improved the fitness of previously inactive adults. [5]

Once your body becomes accustomed to shorter bouts, you can start increasing the duration by about 10% each week.

Type – What Type?

Whether you love exercising outdoors or would rather workout inside away from the elements, there are many different ways to squeeze cardio exercise into your life. If you’re not quite ready to commit to an exercise program, you can start by making simple changes, like parking a few blocks away from your office or school and walking the rest of the way. Or better yet, try cycling to work!

At the gym, you can choose between several cardio machines including treadmills, stationary bikes, elliptical trainers, rowing machines, and stair masters. The elliptical trainer (also known as a cross-trainer) is an excellent option for beginners as it simulates running without placing excessive pressure on your joints. Elliptical trainers require you to push and pull with your upper body too, which recruits more muscles and increases calories burned.

Most gyms also offer several cardio-based group exercise classes that can make exercise more social and fun, such as circuit training, body step, cycle, or boxing. Low-impact options include swimming, aqua aerobics, and Zumba.

One of the most popular types of cardiovascular exercise at the moment is High-Intensity-Interval-Training (HIIT). HIIT is a form of intermittent training that involves alternating between “work” periods of maximum intensity and “rest” periods of low-intensity.

The work periods are typically short—anywhere from 10 seconds to 90 seconds. During strenuous work periods, you’re primarily working anaerobically (without oxygen), while during rest periods you’re working aerobically (with oxygen) to recover. This creates an oxygen deficit that increases post-exercise exercise oxygen consumption (EPOC), which means you continue to burn calories even after you’ve finished your session.

HIIT is a crowd pleaser because you can burn the same amount of calories as continuous aerobic exercise in less time. In fact, studies show HIIT is highly effective for fat loss and improving body composition. [6] Although, due to it’s intense and dynamic nature, HIIT isn’t for everyone. It’s important to choose a type of exercise that you’re physically ready for.

Importance of Warming up Before Cardio

Before participating in any type of cardiovascular exercise, it’s important that you slowly warm up your body temperature and gradually increase blood flow to your muscles. Taking the time to warm up will help you get the most out of your session and reduce your risk of injury.

Begin with a low-intensity activity, such as brisk walking, slow jogging or skipping, for about 5 to 10 minutes. You can gradually increase your pace to raise your heart rate steadily, but you should still be able to hold a conversation throughout the warm-up.

Follow up with several dynamic stretches to help increase your range of motion. Dynamic stretches are active stretches that involve moving through a range of motion, as opposed to static stretches, which involve holding one position. Some great dynamic stretches to perform before cardiovascular exercise include inchworms, trunk rotations, walking lunges, or leg swings.

Importance of Cooling Down After Cardio

Once you’ve finished your workout, soak up those post-workout endorphins with 5 to 10 minute cool down. Start with an active recovery of slow walking or light cycling. This will gradually lower your heart rate and return your body temperature back to normal. After strenuous exercise, active recovery also plays an essential role in clearing the build-up of by-products, like lactic acid.

Following active recovery, end your workout with 5 minutes of gentle static stretching. Aim to target the main muscle groups used in your session and hold each stretch for at least 30 seconds. Static stretching can improve performance and may help reduce muscle soreness post-exercise. [7] [8]

Getting Started With Cardiovascular Exercise

Taking steps towards a more active lifestyle is one of the best things you can do for your health. However, if you’ve been inactive for an extended period of time or have heart disease or any chronic health problem, it’s important that you consult with your health care provider before beginning any type of exercise program.

References

[/restrict]