Returning to Exercise After Cardiovascular Events: A Full Breakdown of the Phased Concept of Cardiac Rehabilitation and Absolute Contraindications

Medical Disclaimer: This article is a compilation of educational health information designed to help readers who have experienced a myocardial infarction, undergone cardiac surgery, received a stent, or have a history of other cardiovascular events understand the general staged concepts of cardiac rehabilitation and returning to exercise. It does not constitute a medical diagnosis, treatment recommendation, or a substitute for the evaluation of your individual condition by a cardiologist and cardiac rehabilitation team. When and how to return to exercise after a cardiovascular event, and at what intensity, varies greatly. You must have this evaluated by your medical team before proceeding. Do not use this article to set your own training plan or adjust your medication.

Why “Returning to Exercise” Requires Particular Caution for This Population

In Taiwan’s cycling and running communities, it’s not uncommon to hear stories of people who “cherish their body more after a near-death experience and start exercising seriously”—someone gets a stent after a myocardial infarction and, upon discharge, treats cycling as part of their rehabilitation; another undergoes coronary artery bypass surgery and, after six months of recovery, returns to the familiar riverside bike path. These stories are inspiring, but they also make it easy to overlook an important fact: returning to exercise after a cardiovascular event is a medical process that requires professional team involvement and has clearly defined stages. It is not something you can plan on your own through sheer willpower or by referencing online articles.

Cardiac Rehabilitation is listed as a crucial component of post-cardiovascular-event care in cardiac care guidelines across many countries and regions. It is typically delivered by a team comprising cardiologists, rehabilitation physicians, physical therapists, exercise physiologists, and nursing staff, who help patients safely restore daily activities and exercise capacity through staged, monitored programs. This article discusses precisely this general concept of “staging,” as well as which situations constitute absolute contraindications to exercise. The goal is to help you better understand which stage you are in and what questions to ask when discussing with your medical team—not to replace the medical team’s judgment.

The Staged Concept of Cardiac Rehabilitation: It’s Not as Simple as “Once You’re Better, You Can Ride”

Stage 1: Activity During Hospitalization

After a cardiovascular event, the first stage of activity typically occurs during hospitalization. The medical team assesses the stability of your condition and gradually guides you from lying in bed, to sitting up, to standing, and then to short-distance walking within the ward. The goal of this stage is very simple: to confirm that your body can tolerate the most basic daily activities and to prevent complications from prolonged bed rest (such as deep vein thrombosis and muscle atrophy). It involves no intensity training whatsoever, and all activity is conducted under the supervision of the medical team.

Stage 2: Supervised Cardiac Rehabilitation After Discharge

After discharge, many cardiac rehabilitation programs arrange a period of medically supervised training. During this phase, patients undergo progressive exercise training under ECG monitoring at hospital or rehabilitation center cardiac rehabilitation clinics. Exercise intensity is determined based on the patient’s current cardiopulmonary function assessment (e.g., results from an exercise ECG test) and is gradually adjusted as the body adapts. The focus of this stage is to safely confirm the body’s response to exercise load under full professional supervision, while also educating patients about their heart condition, medications, and warning signs to watch for during future exercise.

This stage typically lasts anywhere from several weeks to several months, with the actual duration varying from person to person, depending on the severity of the original cardiovascular event, whether surgical intervention was performed, comorbidities, and individual recovery progress. This timeline cannot be accelerated on your own. Skipping or shortening this stage and returning directly to high-intensity training is considered to increase the risk of another cardiovascular event.

Stage 3: Community or Home Maintenance Exercise

After completing supervised cardiac rehabilitation, most patients enter a relatively independent maintenance phase, though regular follow-up visits are still recommended. During this stage, patients can exercise on their own in community settings or at home—for example, riding familiar riverside bike paths or joining community walking groups. However, the exercise intensity and type should still follow the personalized recommendations provided by the cardiac rehabilitation team, and patients should continue to pay attention to signals from their body.

For patients hoping to return to endurance sports like cycling or running, this stage is typically the time to discuss with their physician whether they can “challenge longer distances or more difficult routes.” However, it must be emphasized: any substantial increase in intensity—such as progressing from flat-ground riding to long climbs, or from walking to running training—should be discussed with your medical team first to confirm that your current cardiopulmonary function and cardiac condition are suitable. Do not simply challenge yourself based on feeling that your body is fine.

Why You Can’t Rush: General Concepts of Cardiac Tissue Healing and Electrical Stability

When a myocardial infarction occurs, part of the myocardial tissue is damaged due to interrupted blood flow. Over the following weeks to months, this damaged tissue undergoes processes of inflammation, repair, and scarring. During this period, the heart’s structure and electrical conduction stability may still be changing. Applying high-intensity exercise loads too early is generally considered to potentially increase the risk of arrhythmias or other cardiovascular accidents. For patients who have undergone cardiac surgery (such as bypass surgery), the sternum and wounds themselves also need time to heal. Performing movements that require upper limb force or increased intrathoracic pressure too early (including certain handlebar loading positions in cycling, or weight training) may affect wound healing.

For patients who have received a coronary stent, although the recovery period is usually shorter than for surgical patients, they still need to take antiplatelet medications as prescribed for a period of time to reduce the risk of stent thrombosis. During this period, medication adherence and exercise planning should also be discussed and coordinated with your physician. In particular, the bleeding risk from trauma associated with antiplatelet medications and certain exercises needs to be considered together. Only a physician can determine whether medication adjustments are needed for your exercise plan.

The key point of these mechanisms is this: after a cardiovascular event, the body is not “healed just because symptoms have disappeared.” Internal healing and adaptation take time. This is why cardiac rehabilitation emphasizes a staged, progressive approach rather than recklessly increasing intensity based on feeling good.

Absolute Contraindications to Exercise: Situations Where You Should NOT Exercise

In the fields of cardiac rehabilitation and sports medicine, certain conditions are generally listed as absolute contraindications to exercise. This means that until these conditions are stabilized or cleared by the medical team, no form of exercise training should be performed—including seemingly gentle activities like walking or easy riding:

• Unstable angina: Increased frequency of chest pain episodes, worsening severity, or episodes occurring at rest are signs that the condition is not yet stable.
• Uncontrolled arrhythmias: Arrhythmias accompanied by significant hemodynamic instability (e.g., dizziness, dropping blood pressure, altered consciousness).
• Unstable acute heart failure: When symptoms such as significant shortness of breath, worsening lower limb edema, or inability to lie flat are not yet controlled.
• Severe uncontrolled hypertension: Blood pressure readings significantly above safe ranges and not yet stabilized with medication.
• Acute myocarditis or pericarditis: The heart is in the acute phase of inflammation.
• Severe aortic stenosis with associated symptoms: This type of structural heart disease can trigger serious complications during exercise.
• Recent pulmonary embolism or deep vein thrombosis not yet stabilized: The acute phase of thrombotic disease.
• Acute systemic illness or fever: Even for patients with stable cardiac conditions, it is not recommended to force exercise during the acute phase of an infection or fever.

The above list is intended only to help readers understand that the concept of “absolute contraindications” does exist—not for readers to self-assess their symptoms and decide whether they can exercise. For any patient with a history of cardiovascular disease, the initiation of an exercise plan and intensity adjustments should be determined by the medical team based on complete examination results (ECG, echocardiography, exercise ECG testing, etc.). The list in this article cannot serve as a basis for self-screening.

What Aspects Are Generally Considered When Returning to Cycling or Running

For patients who have completed cardiac rehabilitation and are medically stable, if the goal is to return to cycling cruising, riverside jogging, or even challenging more difficult routes (such as Wuling, the long climbs of Beiyi, or half and full marathons), the medical team will generally consider the following aspects during evaluation. This list is provided to help readers understand the evaluation logic—it is not a self-assessment tool:

It is particularly important to note that challenging routes like Wuling—which involve long duration, high intensity, and high altitude—place a far greater load on the cardiovascular system than typical cruising rides. Even healthy riders are advised to prepare progressively. For patients who have experienced a cardiovascular event, whether such challenges are appropriate and how to prepare for them must be carefully evaluated by the medical team. It is not recommended to set such challenges as an early rehabilitation goal.

Self-Monitoring During Exercise: Understanding Without Replacing Medical Judgment

Cardiac rehabilitation teams typically teach patients some simple self-monitoring methods to help them maintain basic awareness of their physical condition during home or community exercise. However, these methods are supportive tools and cannot replace regular follow-up visits and professional examinations.

Rating of Perceived Exertion (RPE): Using the subjective sensation of breathlessness and muscle fatigue to roughly gauge whether exercise intensity falls within the recommended range. Subjective scales of this type (such as the Borg Rating of Perceived Exertion scale) are commonly used intensity reference tools in cardiac rehabilitation. Their advantage is that they are not affected by medications that alter heart rate response.

Heart rate monitoring: Some patients are asked to monitor their heart rate during exercise. However, as mentioned earlier, for patients taking medications such as beta-blockers, the heart rate response to exercise load is suppressed by the medication. In such cases, heart rate numbers may not accurately reflect actual exercise intensity. This is why cardiac rehabilitation teams often use RPE as a supplementary measure rather than relying solely on heart rate numbers.

Symptom monitoring: Chest tightness, chest pain, unusual shortness of breath, dizziness, palpitations, and abnormal fatigue are all signals that require stopping to assess during exercise. If any of these occur, you should not “push through” or “rest a bit and continue.” Instead, you should stop exercising, record what happened, and fully inform your physician at your next follow-up visit.

The Role of Family and Riding Companions

For patients who have experienced a cardiovascular event, it is recommended to avoid exercising alone when returning to cycling or running—especially when tackling more difficult routes or during the early stages of resuming training. Having family members or riding companions who are familiar with your condition ride with you, and making sure they understand your medical history, medications, and what to do in case of an emergency (e.g., whether you carry emergency medications like nitroglycerin, emergency contact information), can buy critical response time if something actually happens. Some long-distance challenge routes in Taiwan have sections with few people, sparse traffic, and unstable mobile phone signals. These environmental factors are also worth considering when planning routes for returning to exercise.

The Psychological Dimension: Both Fear and Overconfidence Need to Be Understood

After a cardiovascular event, many patients experience two seemingly opposite psychological states that can both affect safety. One is excessive fear—being so afraid of another episode that they completely avoid exercise, which over time can actually harm overall cardiovascular health due to declining fitness and weight gain. The other is overconfidence—thinking “I survived this, so my body must be strong,” and rushing to prove they can still keep up with past training volumes and racing performance, while ignoring the importance of gradual progression.

In helping patients return to exercise, cardiac rehabilitation teams typically pay attention not only to the physiological side of training but also to psychological adjustment. When necessary, they may recommend psychological counseling or patient support group resources. If you find yourself completely avoiding exercise out of fear, or if you find yourself ignoring your body’s warning signals and pushing through to complete a training plan, both tendencies are worth proactively discussing with your medical team to seek help in adjusting your mindset.

These Situations: Stop Exercising Immediately and Seek Medical Attention

For patients who have experienced a cardiovascular event, if any of the following occurs during or after exercise, stop immediately. Call 119 if necessary and seek medical attention. Do not force yourself to finish the workout or wait for symptoms to resolve on their own:

• Recurrence of chest pain, chest tightness, or pressure: Even if milder than previous episodes, this should be treated as an important warning sign and not taken lightly.
• Discomfort different from previous episodes: Changes in pain location or nature, or symptoms you have never experienced before.
• Significant shortness of breath: Gasping for air, inability to lie flat, or being suddenly awakened at night by breathlessness.
• Palpitations accompanied by dizziness or a feeling of near-fainting: May be related to arrhythmias.
• Abnormal cold sweats with nausea: Especially when combined with chest tightness or chest pain, a high suspicion of recurrent cardiac events is warranted.
• Marked worsening of lower limb edema: Rapid weight gain over a short period, or increased swelling in the legs or abdomen.
• Syncope or loss of consciousness: Even a brief loss of consciousness requires immediate medical evaluation of the cause.
• Abnormal wounds (for post-surgical patients): Redness, swelling, heat, pain, pus, fever at the surgical wound, or abnormal movement sensation in the sternum area.

Any of the above—especially chest pain or tightness combined with cold sweats, shortness of breath, or altered consciousness—constitutes a combination highly suggestive of a cardiac emergency. Call 119 immediately. Do not drive yourself to the hospital, and do not delay seeking medical attention by thinking “it was like this last time too, it’ll pass if I rest.”

Comparison of the Three Stages of Cardiac Rehabilitation

To help readers more easily grasp the differences between the three stages, the table below provides a rough comparison. Actual content and duration are subject to the arrangements of the medical team:

The key point this table emphasizes is this: even when entering the relatively independent Stage 3, “not being under real-time supervision” does not mean “no limits.” Any major change in intensity or type—such as transitioning from flat-ground riding to challenging long climbs, or from walking to running training—should still be discussed with your medical team first.

Clarifying Common Misconceptions

Misconception 1: “If my test results are normal, I can return to my pre-illness exercise intensity.”
Normal test results are one of the necessary conditions for returning to exercise, but they do not mean you can immediately return to your pre-event training intensity and volume. The progressive recovery emphasized in cardiac rehabilitation means that even when all examination data are within reasonable ranges, intensity should still be increased gradually, allowing the body’s overall adaptation (not just the heart, but also the coordination of blood vessels, muscles, and the autonomic nervous system) to catch up step by step—not all at once.

Misconception 2: “The stent is in place and the vessel is open, so I don’t need to be as careful with exercise as before.”
The stent addresses the blockage in a specific vascular segment, but cardiovascular disease is often part of systemic vascular pathology. After stent placement, you should still take medications as prescribed, control other risk factors (lipids, blood glucose, blood pressure, weight, smoking cessation), and continue to follow the exercise intensity recommended by your medical team. Do not let your guard down just because a stent has been placed.

Misconception 3: “I could conquer Wuling before, and I feel fine now, so I should be able to do it again.”
Feeling subjectively good does not fully equate to the heart’s objective function having recovered to a level capable of withstanding high-altitude, long-duration, high-intensity loads. Before challenging such routes, it is recommended to assess your cardiopulmonary functional limits through objective methods such as exercise ECG testing, rather than relying solely on subjective feelings.

Misconception 4: “The harder I push during rehab exercise and the more I sweat, the better the results.”
Exercise intensity during cardiac rehabilitation is a prescription based on individual cardiopulmonary function assessment. Excessively pursuing intensity beyond the recommended range will not accelerate recovery; it may actually increase risk. The goal of rehabilitation is safe, progressive adaptation—not intensity breakthroughs in a short period.

The Relationship Between Medication Adherence and Exercise Safety

Patients after a cardiovascular event typically have a prescription that includes multiple medications, which may include antiplatelet agents, lipid-lowering drugs, antihypertensive medications, and heart rhythm control medications. Taking these medications regularly is itself a crucial part of reducing the risk of another cardiovascular event—no less important than exercise itself. Regular exercise cannot replace regular medication. The two are parallel care strategies, not interchangeable options.

Some patients develop a mindset of “I’m exercising seriously now and my lifestyle has improved, so maybe I can take fewer medications.” This idea must be discussed with your physician before acting on it. You must never reduce or stop your medication on your own. Even if your exercise performance improves and your fitness clearly gets better, that does not mean you can adjust your medication yourself. The protective mechanisms of medication and exercise on the cardiovascular system are not identical, and the two are typically used in combination.

If medication side effects (such as fatigue, muscle soreness, or orthostatic hypotension) make you feel uncomfortable during exercise, the correct approach is to tell your physician about this issue at your follow-up visit and let the physician assess whether the medication type or dosage needs adjustment—rather than reducing or stopping it yourself to “feel more comfortable during exercise.”

For Readers Hesitating About Returning to Exercise

If you are in the aftermath of a cardiovascular event and have not yet started—or are hesitating about whether to return to endurance sports like cycling or running—the most practical first step is not to find an article telling you “how to train.” Instead, proactively discuss with your cardiologist your goal of returning to exercise and ask whether a referral to a cardiac rehabilitation clinic is appropriate. Most medical centers and some regional hospitals in Taiwan have cardiac rehabilitation clinics or services. Through evaluation and supervision by a professional team, you can more safely and systematically rediscover exercise—rather than figuring it out on your own and taking unnecessary risks.

Key Takeaways

• Cardiac rehabilitation is generally divided into three stages: in-hospital activity, supervised training, and community maintenance. Each stage has different goals and levels of supervision, and the process should not be skipped or accelerated on your own.
• Myocardial tissue healing after a heart attack, wound recovery after cardiac surgery, and antiplatelet therapy after stent placement all take time. Exercising at high intensity too early is considered to increase risk.
• Unstable angina, uncontrolled arrhythmias, acute heart failure, and other conditions are absolute contraindications to exercise. Exercise can only be considered after the condition is stabilized and cleared by the medical team.
• For those taking medications such as beta-blockers, heart rate cannot accurately reflect exercise intensity. It is recommended to combine other monitoring methods such as RPE and discuss a personalized plan with your medical team.
• Before returning to high-intensity or high-difficulty routes (such as long climbs or running races), you must have your medical team assess whether your current cardiopulmonary function is suitable. It is not recommended to increase intensity on your own.
• It is recommended to avoid exercising alone during the early stages of returning to exercise. Make sure companions understand your medical history and emergency procedures.
• If warning signs such as recurrent chest pain or tightness, significant shortness of breath, or syncope occur, stop exercising immediately and call 119 for transport to the hospital.

Reminder Again: This article is only a compilation of educational health information intended to help readers understand the general staged concepts of returning to exercise after a cardiovascular event. It cannot replace the professional evaluation of your individual medical condition by a cardiologist and cardiac rehabilitation team. When to start and at what intensity to exercise must be fully discussed with your medical team before proceeding. If any of the aforementioned warning signs occur during exercise, prioritize your personal safety above all else—stop immediately and call 119 for transport to the hospital.

Related Reading

• Returning to Cycling After Heart Surgery: The Rehabilitation Journey from Hospital Bed to Bike Saddle
• Safe Exercise for Heart Disease Patients: From Exercise Prescription, Monitoring to Warning Signs—A Coach’s Step-by-Step Guide
• Returning to Running: A Progressive Return-to-Run Plan After Injury
• Returning to Exercise During Pregnancy and Postpartum: Staging Principles and Absolute Contraindications (All Subject to Individual Evaluation by an Obstetrician)