Energy drinks, pre-workout supplements and caffeinated beverages have become common among people who want a quick energy boost, stay alert at work or improve their gym performance. While caffeine in small amounts can be tolerated by many healthy adults, consuming too much at once can put extra pressure on the heart. Caffeine stimulates the nervous system, which can temporarily increase heart rate and blood pressure.

According to Dr Manish Aggarwal, Director, Interventional Cardiology, Yashoda Medicity, large or concentrated doses of caffeine can cause palpitations, anxiety and, in sensitive people, more serious heart rhythm problems. Dr Praveen Raman Mishra, Associate Consultant, Cardiology, ShardaCare-Healthcity, also warns that energy drinks and pre-workout products can deliver concentrated amounts of stimulants. When these are taken before intense exercise, the cardiovascular system faces additional stress. For most healthy adults, around 400 mg of total caffeine a day is generally considered acceptable, but individual tolerance can vary.

How Does Caffeine Affect The Heart?

Caffeine acts as a stimulant and activates the body's nervous system. This can cause a temporary increase in alertness, energy and concentration. At the same time, it can make the heart beat faster and cause blood vessels to constrict, which may raise blood pressure.

Dr Mishra explains that high concentrations of caffeine can increase hormones involved in the body's "fight-or-flight" response. As a result, blood vessels may constrict and the heart may contract with greater force. For most people, moderate caffeine intake does not automatically mean heart damage. However, the response can differ depending on a person's health, sensitivity to caffeine, the amount consumed and how quickly it is consumed.

When Does Caffeine Become Too Much?

For a generally healthy adult, about 400 mg of caffeine per day is commonly considered an upper amount that can usually be tolerated. This is a total from all sources, and not 400 mg from each drink.

The amount can add up quickly. A person may have coffee in the morning, an energy drink later, a caffeinated soft drink in the afternoon and a pre-workout supplement before exercising. Individually, these products may not seem excessive, but together they can increase your caffeine intake well beyond the recommended amount.

Pre-workout products can be particularly difficult to assess because their formulas may contain caffeine along with other stimulant ingredients. Energy drinks can also contain multiple stimulating compounds. Therefore, checking the caffeine content on labels is important.

Why Are Energy Drinks And Pre-Workouts A Concern?

Energy drinks and pre-workout supplements are often consumed in concentrated doses, sometimes shortly before physical activity. This combination can put additional demands on the cardiovascular system.

"Performing activity soon after having multiple doses of stimulants puts additional strain on the cardiovascular system," says Dr Aggarwal.

During exercise, the heart naturally works harder to supply blood and oxygen to the muscles. Adding a large amount of stimulants beforehand may further increase heart rate and blood pressure.

According to Dr Mishra, people may experience uncomfortable acceleration of the heart rate, palpitations, anxiety and, in some cases, abnormal heart rhythms. Such rhythm problems can happen even in younger people who have no previously diagnosed heart condition.

What Symptoms Should You Watch For?

The body's reaction can provide an important warning that caffeine or another stimulant is not being tolerated well. Possible symptoms after consuming large amounts include:

  • Palpitations or a racing heartbeat
  • Skipped or irregular heartbeats
  • Increased anxiety or restlessness
  • Dizziness
  • Rapid heart rate during exercise
  • Increased blood pressure

Occasional mild symptoms may improve as the stimulant wears off, but persistent or severe symptoms should not be ignored. Dr Aggarwal advises seeking medical attention for chest pain, fainting, severe shortness of breath or a very noticeable, constant or irregular heartbeat after using a stimulant.

Who Needs To Be More Careful?

Not everyone should assume that the general 400 mg daily limit is appropriate for them. People with high blood pressure, known heart rhythm disorders or other heart conditions may need to restrict caffeine more significantly.

Dr Aggarwal recommends that people with these conditions speak to their doctor before using energy drinks or pre-workout supplements. Depending on their health, they may need to avoid stimulants altogether or keep their caffeine intake lower. People who take certain medications should also discuss caffeine and stimulant use with their doctor, as some medicines and health conditions can affect how the body responds to stimulants.

How To Use Caffeine More Safely

The safest approach is not necessarily to eliminate caffeine completely, but to understand how much you are consuming and avoid concentrated doses. Keep these points in mind:

  • Track your total caffeine intake: Count coffee, tea, energy drinks, pre-workouts, soft drinks and other sources.
  • Read product labels: Check how much caffeine is present in each serving.
  • Avoid stacking stimulants: Do not combine multiple energy drinks or stimulant-heavy products.
  • Be cautious before exercise: Avoid taking large doses of stimulants immediately before intense workouts.
  • Pay attention to symptoms: Palpitations, dizziness or an unusually rapid heartbeat are reasons to stop and reassess your intake.
  • Consult a doctor if you have heart problems: Individual limits may be lower than the general recommendation.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.