One of the hallmarks of a great workout is the feeling of your heart pounding in your chest. Typically, things that raise your heart-rate are fast-paced and full-body activities. The higher the intensity of the exercise, the higher your heart rate will be.
Sprints are a more accessible activity than push-ups because they don't require as much strength or technique. If you're looking for a workout that will make your heart rate skyrocket, then sprinting is a great option because it is fast-paced and uses big muscles.
Read More: How to Sprint Faster in a Week
What Raises Heart Rate?
The higher the intensity of the activity that you're doing, the faster your heart has to beat. It works hard to move blood around your circulatory system for two reasons: to deliver nutrients to your muscles and to clear waste.
Your body releases hormones, like adrenaline, that cause your heart rate to increase when you exercise. This hormone helps you move energy around the body in the form of glucose and other molecules that supply your muscles with energy to contract. The more intense the activity that you do, the more adrenaline you produce, and the higher your heart rate will be.
Short-burst activities, like push-ups and sprints, raise your heart rate, as does steady-state exercise like jogging. With the short, intense activities, however, it takes a bit longer for your heart rate to come down to a resting level according to a 2007 study in the American Journal of Physiology.
The researchers compared how quickly someones heart rate slows down after a sprint compared to jogging. They found that heart rate stays elevated longer in short burst exercises because they are more intense and raise your heart rate to a higher level than steady-state workouts. Push-ups and sprints are similar in that they are short, intense activities.
Flushing Out the Blood Stream
As your muscles use energy they also create waste. Something called "lactic acid" is one of the most well-known types of waste. It would be dangerous if these molecules stayed in your muscles, so you need blood pumping through to remove them. Your blood stream also picks up carbon dioxide from your body and brings it to your lungs. The amount of carbon dioxide in your body increases during exercise and it's important to remove because it can become toxic.
When your heart rate rises with exercise, it means you're pumping blood through your system more quickly to help rid yourself of this waste that you're producing at a rapid rate. An intense set of push-ups and a sprint both produce muscular and CO2 waste.
Difference Between Upper and Lower Body
Upper body and lower body activities affect your heart rate differently. When you do an upper body exercise, such as push-ups, your heart rate initially increases very quickly. That's because blood isn't returning to the heart very fast and it needs to beat quickly to keep blood moving through the body. The smaller muscles of your upper body don't push blood back to your heart as quickly as the muscles of your lower body do.
Read More: Heart Rate on Treadmill
Your veins, which return blood to the heart, are surrounded by muscles. When muscles contract, they squeeze the veins and push blood towards the heart. If your upper and lower body muscles are contracting and pushing blood back towards the heart, your heart doesn't have to work as hard.
In push-ups you are really only using your chest, shoulders, triceps and core. In a sprint, you are using your legs, core and even your shoulders to pump your arms. With all of those muscles pumping blood back to the heart, it doesn't have to work as quickly initially. But, once you go longer than a few seconds -- your heart rate will soar during an all-out sprint, far more than it will during a max set of push-ups.