Everything You Need to Know About Interval Training

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There's a better way to increase cardiovascular fitness: Interval training. Steady state training has its place in any workout routine, but a dose of interval training may be just what you need to rejuvenate your workouts and boost your fitness.

Athletes have been using interval training for years to increase performance, but you don't have to be an elite athlete to get the benefits in your own training. 

What Is Interval Training?

Unlike staying at the same pace or intensity during cardio, interval training involves alternating segments of high-intensity exercise with periods of rest. This allows you to work more in a shorter period of time and it's much more comfortable than spending the entire workout at a high intensity.

Another plus is that it works for all types of exercisers. For beginners, aerobic intervals offer a safe and comfortable way to push out of the comfort zone and, for seasoned exercisers, anaerobic intervals make workouts more challenging and effective. It's even been shown to improve patients with COPD and metabolic syndrome.

The key is to create workouts that fit what you can handle and what you want from your workouts.

7 Benefits of Interval Training

  • Increased endurance — Interval training trains your heart to pump more blood to the muscles and it trains your muscles to extract oxygen from it more efficiently, making all your other workouts easier to handle
  • More efficient workouts — If you don't have much time, interval workouts are great timesavers, allowing you to get a lot done in a shorter period of time
  • More fuel efficiency — Interval training enhances your body's utilization of fats and carbs
  • More power and endurance — Working at high intensities raises your lactate threshold and improves your performance
  • Reduced risk of injury — Because you're varying intensity, you may be able to avoid overuse injuries or overdoing it with longer workouts
  • More fun - Interval workouts have much more variety than other workouts, making them less tedious
  • Weight loss - Studies show that interval training, even at a moderate intensity, may burn more fat and, if you work hard enough, can increase afterburn

Approach with Caution

While there are a number of benefits, interval training isn't for everyone, particularly high-intensity interval training (HIIT) or anaerobic training. Anaerobic intervals are very challenging on the body and, if done too soon or too often, can lead to injuries or overtraining. It's important to ease into interval training and gradually build more stamina over time to avoid these kinds of problems.

There are two types of interval training: aerobic and anaerobic. The latter is more popularly known as high-intensity interval training or HIIT, and it is having its moment in the fitness spotlight.

Aerobic Interval Training (AIT)

AIT, which some experts also call fitness interval training, focuses on working harder during your intervals, but not going all out, as you do with anaerobic training. AIT involves alternating moderate to high-intensity exercise (e.g., running briskly) with a recovery period (e.g., walking). The idea is to work harder during work intervals while keeping the intensity below 85 percent of your maximum heart rate or at Level 7-8 on this perceived exertion scale.

Who Should Do It

AIT is great for any level of fitness. Beginners can keep the work intervals at a moderate intensity to fit their fitness levels, while more advanced exercisers can change the length of each interval to make the workouts more challenging.

How to Do Fitness Intervals

  1. Choose any cardio activity — This can work with any machine or activity: running, cycling, walking, elliptical, jumping rope, kickboxing etc.
  2. Choose the length of your workout — This might be 10-20 minutes for beginners or 30-60 minutes for more advanced exercisers.
  3. Choose the length of your work/recovery intervals — Because you're staying aerobic, you can create any work/recovery ratio you like. If you're a beginner, you might alternate 1-2 minutes hard with 5 or more minutes easy. The more advanced may make their work intervals longer (e.g., 10 minutes) and their recovery intervals shorter (e.g. 2 minutes).
  4. Start your workout with a 5-10 warm-up followed by your work and recovery intervals. Alternate each for the length of the workout.
  5. End with 5 minute cool down and stretch.

How Often Should You Do Intervals?

This type of training (providing you're staying aerobic) can be done two or more times a week, depending on your workout schedule. 

Aerobic Interval Training Workouts to Try

Anaerobic Interval Training

Also known as High-Intensity Interval Training (HIIT), anaerobic intervals involve going all out during your work intervals. That means shorter intervals at 85 to 100 percent of your maximum heart rate or Level 9-10 on this perceived exertion scale. Your recovery intervals will usually last as long or longer than your work intervals, to allow your body to fully recover for the next interval.

Who Should Do It

More advanced, experienced exercisers or athletes who want to push their limits, increase fitness and performance and don't mind working at very uncomfortable intensity levels.

How to Do HIIT

  1. Choose any cardio activity — This can work with any machine or activity, as long as you're able to work as hard as you can during work intervals.
  2. Choose the length of your workout — Anaerobic of HIIT workouts are usually shorter because they're so challenging. You might keep this workout to 20 minutes, depending on your fitness level and level of exertion. If you can go longer, you aren't working at a high enough intensity.
  3. Choose the length of your work/recovery intervals — Experts generally recommend a 1:2 work to rest ratio, which means your rest interval is twice as long as your work interval. An example would be sprinting for 30 seconds and walking to recover for one minute. If you work at maximum effort, you may need even longer to recover.
  4. Start your workout with a 10 to 15-minute warm-up to make sure your body is ready for intense exercise. Follow up with your work and recovery intervals, alternating each for the length of the workout.
  5. End with cool down and stretch.

How Often Should You Do HIIT

High-intensity interval training is very challenging and it's easy to overdo it if you do it too often. Most experts recommend this kind of training 1-2 times a week with rest or light aerobic workouts in between. Make sure there is at least 24 to 48 hours between each workout so that you have given your body plenty of time to recover.

Anaerobic or High-Intensity Interval Training Workouts to Try

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