The harder your body works during exercise, the more calories you burn and the more noticeable your training results will be. Doing high-intensity sprint intervals not only increases endurance as much as jogging, but it also burns significantly more calories due to the excessive oxygen uptake involved in the exercise. Still, excessive oxygen uptake is difficult for the body to sustain, so sprinting isn't for the faint of heart.
Oxygen Uptake and Heart Rate
Although it's nearly impossible for the average person to measure specific oxygen uptake during exercise, your heart rate is the key to understanding your body's level of exertion. Working between 60 and 80 percent of your maximum heart rate puts you in an aerobic cardio zone, while exceeding 80 percent pushes you into the anaerobic zone. The harder your body works, the more oxygen you take in and the faster your heart beats. Men can estimate their maximum heart rate by subtracting their age from 220. Women need to use a more complex formula by subtracting 88 percent of their age from 206.
Your body requires oxygen to power the energy-production process during cardio training, but running sprints forces your muscles to contract much more quickly than when you jog. Since you're asking much more out of your body during a sprint than a jog, you need instant energy, which is supplied through the breakdown of glycogen stores. This process is anaerobic because it doesn't require oxygen during exercise, but directly following a sprint, your oxygen uptake increases significantly to compensate for the oxygen deficit you incurred during your workout.
Since jogging isn't as intense as sprinting, you enter a steady-state cardio zone where you are able to take in oxygen at a rate high enough to keep you from pushing into an anaerobic zone. Still, heart rate can increase gradually during jogging, particularly in hot conditions, due to a phenomenon known as cadiac drift. Although the exact cause of cardiac drift is unknown, it's believed to be affected by increased core body temperature during exercise.
Anyone with a history of heart conditions should be wary of sprinting intervals, since they put a lot of stress on the cardiovascular system. But if you want to increase your weight loss results, sprinting will be more effective than jogging. Sprinting for short bursts, then walking, increases your endurance as much as long sessions of cardio training, according to a 2008 study published in the "American Journal of Physiology."