You use the harder the heart has to work.
A number of things could effect the results i.e., if you were stressed , medication, eating before the exercise. If .
You use an electronic pulse machine it would have gave a more accurate reading.
CONCLUTION.
According to (Collins et- senior-Boyle , p,181)The human heart beats over 100, 000 times a day, creating the pressure to force blood through more than 80,000 kilometres of veins, arteries, capillaries.
The heart responds to exercise like any other muscle; it enlarges, although the nature of the enlargement depends on the type of exercise done.
(Tortora p,662,02) believes no matter what a persons level of fitness, it can be improved at any age with regular exercise.
Of the various types of exercise some are more effective than others for improving the health of the cardiovascular system.
Aerobics, any activity that works large body muscles for at least 20 minutes elevates cardiac output and accelerates metabolic rate.
Three to five such sessions a week are usually recommended for improving the health of the cardiovascular system.
Brisk walking, running, bicycling, cross country skiing are examples of aerobic activities.
Sustained exercise increases the oxygen demand of the muscles.
Whether the demand is met depends primarily on the adequacy or cardiac output and proper functioning of the respiratory system. After a number of weeks training, a healthy person increases maximal cardiac output, there by increasing the maximal rate of oxygen delivery to the tissues.
Oxygen delivery also rises because haemoglobin level increases and skeletal muscles develop more capillary networks in response to long term training.
Smoking may cause a person to become easily "winded" with even moderate exercise because several factors decrease respiratory efficiency in smokers, nicotine constricts terminal bronchioles, which decreases airflow into and out of the lungs.
Carbon monoxide in smoke binds to haemoglobin and reduces its oxygen carrying capability.