As an expert in the field of cardiovascular health, I can provide you with information on what constitutes a dangerously high heart rate during exercise. A dangerously high heart rate during exercise can be subjective and depends on various factors, including a person's age, fitness level, and any underlying health conditions. However, a general guideline is that if your heart rate exceeds 85% of your maximum heart rate (MHR), which is calculated by subtracting your age from 220, it is considered to be in a high-intensity zone. For example, if you're 45 years old, your MHR would be 175 beats per minute (bpm), so a heart rate above 148 bpm (85% of 175) would be considered high. It's important to note that while exercising, it's normal for your heart rate to increase, but a rate that is too high can lead to exhaustion, injury, or even more serious health issues. If you experience symptoms such as dizziness, shortness of breath, chest pain, or palpitations, it's crucial to stop exercising and consult a healthcare professional. Additionally, individuals with certain medical conditions or those taking specific medications may have different guidelines for what is considered a safe heart rate during exercise. It's always best to consult with a healthcare provider before starting any new exercise regimen, especially if you have pre-existing conditions. read more >>

The basic way to calculate your maximum heart rate is to subtract your age from 220. For example, if you're 45 years old, subtract 45 from 220 to get a maximum heart rate of 175. This is the maximum number of times your heart should beat per minute during exercise.read more >>