Sinus tachycardia, if there is no primary disease, is only other stimulating factors. Don't take drugs when you rule it out. Your heart rate was 103 beats/min. Actually, it's not too fast (normal heart rate is 60- 100 beats/min). Also, it is necessary to rule out whether it is caused by stimulating drinks such as coffee and wine, or by poor sleep and activities for several days in a row. ......
The safety index of human exercise heart is the bull's-eye rate. Calculation method, 170- actual age = bull's-eye rate, and the positive or negative value of the number does not exceed 10%. Then you can do the math. 170-20= 150.。 In other words, your heart rate during exercise is within 150, which is safe. Of course, you can count your pulse during exercise.