Keeping your heart healthy requires more than simply avoiding unhealthy habits. Regular physical activity plays an important role in maintaining cardiovascular fitness, and according to heart surgeon Dr Jeremy London, people should also make room for workouts that challenge the heart and lungs. In a social media post shared on September 23, Dr London highlighted what he considers a common mistake among adults: avoiding high-intensity exercise and rarely pushing their heart rate beyond a comfortable level. He suggested that, for generally healthy people, getting the heart rate significantly elevated at least once a week may be an important part of maintaining cardiovascular fitness.
Why does raising your heart rate matter?
When you exercise, your heart beats faster to supply working muscles with oxygen-rich blood. As the intensity increases, your cardiovascular and respiratory systems have to work harder to meet the body's increased demand for oxygen. Dr London pointed out that many people are more physically active during their school and college years because sports naturally form part of their routine. However, once those years are over, exercise often becomes less intense. People may continue walking or doing light workouts, but they may rarely perform activities that leave them breathing heavily. According to Dr London, occasionally challenging the cardiovascular system can help maintain and improve fitness.
What is high-intensity exercise?
High-intensity exercise refers to physical activity performed at a level that significantly raises your heart rate and breathing. Depending on a person's fitness level, activities such as running, cycling, rowing, swimming, or skipping can become high-intensity workouts. Dr London referred to reaching around 90% or more of a person's maximum heart rate, often associated with Zone 5 training. At this intensity, breathing becomes difficult and maintaining the effort for a long period can be challenging. However, the appropriate intensity varies considerably from person to person. Someone who is highly trained may tolerate a much harder workout than a person who has been inactive for several months.
What does research say about intense exercise?
Dr London also referred to research examining the effects of exercise training in previously inactive middle-aged adults. The training included high-intensity interval exercise, and participants showed improvements in measures such as aerobic capacity. One commonly used measure of aerobic fitness is VO2 max. It represents the maximum amount of oxygen the body can use during intense exercise and is often used as an indicator of cardiorespiratory fitness. The broader takeaway is that exercise intensity can matter alongside the total amount of physical activity. A combination of regular movement and appropriately challenging workouts can help improve cardiovascular fitness.
How often should you do intense exercise?
Dr London suggested that people should aim to elevate their heart rate substantially at least once a week, while noting that some people may choose to do so twice weekly. This does not mean that everyone needs to perform an extremely difficult workout. The goal should be to challenge the cardiovascular system at an intensity appropriate for an individual's fitness level. For someone who is new to exercise, gradually increasing the duration and intensity of workouts may be more appropriate than suddenly attempting an exhausting session.
What workout does Dr London use?
Dr London said he uses a SkiErg machine to raise his heart rate. The equipment mimics the movement associated with cross-country skiing and provides a demanding cardiovascular workout. He said he typically spends around five to seven minutes on the machine and incorporates these sessions into his routine twice a week. Despite being relatively short, such sessions can be physically demanding because they require sustained effort. For people without access to a SkiErg, there are plenty of alternatives. Running, cycling, rowing, swimming, stair climbing and skipping can all be used to increase cardiovascular intensity.
You don't have to exercise at maximum intensity every day
An important point is that high-intensity training should complement, rather than replace, regular physical activity. Daily walking, moderate cardio, strength training and other forms of movement remain important parts of an overall fitness routine. A short, challenging workout once or twice a week can simply add another level of cardiovascular stimulus. The right balance depends on an individual's age, fitness, lifestyle and health status.
Who should be careful with high-intensity workouts?
High-intensity exercise is not suitable for everyone without consideration. People with known heart conditions or other medical problems should speak with a healthcare professional before starting strenuous exercise. Anyone experiencing chest pain, unexplained shortness of breath, dizziness, fainting or unusual palpitations during exercise should stop and seek medical advice. People who have been inactive for a long period should also avoid jumping immediately into very demanding workouts. Building fitness gradually can make the transition safer and more sustainable.
The bigger picture of heart health
Raising your heart rate during exercise may be one useful component of cardiovascular fitness, but it is not a substitute for a healthy lifestyle. Regular physical activity, adequate sleep, a balanced diet, maintaining a healthy body weight and avoiding tobacco are all important factors associated with better heart health. Dr London's message is therefore less about pushing yourself to exhaustion and more about avoiding a completely sedentary or overly comfortable exercise routine. For healthy individuals, occasionally challenging the heart and lungs through appropriately intense exercise may help build better cardiovascular fitness over time.
