In the study, the results of the exercise here heart rate of people smoking. The same people who do not smoke are the same age. Same gender and weight. By dividing students into 4 groups of studies.
To study the effects of exercise on the heart rate of people who smoke. People who do not smoke The same age, same gender, and weight. Divided into four groups to study.
Study on effect of exercise on the heart rate of people who do not smoke. Smoking, together with the same age, the same sex. น้ำหนักเท่ากัน and divided the studies into 4 group.