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Why You Need Both Anaerobic and Aerobic Workouts
Whether you’re doing low intensity or high intensity, you’re burning calories—but which routine gets you more bang for the buck?
Picture a 30-minute run on the treadmill versus a 30-minute bootcamp workout flipping tires and battling ropes: Same amount of time exercising, but much different experiences. You probably feel like you can maintain your steady state run for a while even after you stop, but it only takes seconds of whipping ropes around before you need to catch your breath. That’s because moderate-paced running is an aerobic form of exercise while the rope routine is anaerobic. “With aerobic exercise, the demand you feel on your body is not ‘all out,’ but with anaerobic exercise you feel like you are giving near-maximum effort,” says Michele Olson, Ph.D., exercise physiologist and clinical professor of sport science at Huntingdon College in Montgomery, AL.
These two different systems refer to the way your body creates and uses energy. Anaerobic exercise involves physical exertion while your body is in a state of oxygen deprivation while aerobic exercise uses oxygen to fuel the movement. Understanding how these processes work will help you burn calories more efficiently and boost your endurance, power and strength. Here’s a closer look at the two types of workouts.
The Deal with Aerobic Exercise
During aerobic exercise, also referred to as cardiovascular conditioning or cardio, your body uses the oxygen you inhale to break down sugars (glucose) and fats in your bloodstream into a form of energy your cells can use to power you through your sweat session. This low to moderate level of exertion can be sustained over long periods, but it still requires effort, and therefore, burns calories. “During aerobic exercise, you breathe faster and deeper than when your heart rate is at rest,” says Olson. “Your heart rate goes up, boosting the amount of oxygen in your blood, and increasing blood flow to the muscles and back to the lungs.”
Aerobic exercise doesn’t cause your muscles to redline, however, because your body finds a balance between the oxygen you take in and the energy you put out, so there is a constant supply of fuel for your workout, Olson explains. Types of aerobic exercise include swimming, running and biking at about 60-70 percent maximum effort.
The benefits of aerobic exercise include strengthening your muscles, including your heart. What’s more, “aerobic activity lowers your blood pressure and blood lipids, and normalizes your blood sugar levels,” says Olson. Basically, you’re building a stronger, healthier body—one that reduces your risk for diseases like diabetes. In addition, cardiovascular activity is beneficial for bone health, keeps you mentally sharp, and helps stave off depression.
Understanding Anaerobic Exercise
In anaerobic exercise, your body is working so hard that it is unable to take in enough oxygen to keep up with energy demands, and instead uses glucose in your body for fuel. “Your body relies on stored energy sources, rather than oxygen itself,” Olson says. Examples of anaerobic moves include box jumps, plyometrics, sprinting or heavy weight lifting. “During anaerobic exercise, you often will recruit your faster, more powerful type 2 fast twitch muscle fibers that can only function for a short amount of time without the help of additional immediate energy,” she says.
The trouble is, during the process of breaking down glucose for energy, several byproducts are produced, including lactic acid. At first, your cells are able to clear this byproduct and keep you exercising, but as time goes on and intensity increases, that lactic acid quickly builds up in your muscles, making it difficult for them to contract. Olson warns this may begin to happen after just 90 seconds to 2 minutes of high-intensity effort. (This is when you get a rest to catch your breath!).
The appeal of anaerobic exercise is that it can burn more calories in a shorter amount of time, and boost your overall power development while building muscle mass. “People love anaerobic activity because it’s the key to building lean muscle mass—and the more lean muscle you have, the more calories your body is able to burn,” Olson adds. After a high-intensity workout, your metabolism functions at a higher rate for several hours after (the “afterburn” effect), so your body is still burning fuel long after you’re done sweating.
Which Is Better?
At the risk of sounding a little wishy-washy, while both exercise types strengthen your body and burn calories, it’s really the combination of the two that will give you maximum results. “You get the power and muscle-building benefits from anaerobic work and the increased stamina and endurance from aerobic exercise,” Olson says.
To capitalize on what each type of exercise delivers, Olson recommends some form of aerobic workouts three times a week and anaerobic routines twice a week. Balance moderate-intensity bike rides with HIIT moves and alternate easy-jog days with sessions of sprinting drills to get your body in top shape.
Listen up, though—if you can only do one exercise, aerobic wins. “The heart-healthy benefits, and the fact that aerobic exercises are perceived to be more enjoyable and tolerable, means you’re more likely to do it—and do it more often,” says Olson. “So aerobic exercise comes out on top.”