How to Get Lean Fast with Interval Training

Get Lean Fast with Interval Training: Lose Fat While Saving Time

The next time you’re watching the Olympics or World Cup or any sport for that matter where the athlete’s sport requires them to primarily perform short bursts of exercise of less than 60 seconds, notice how muscular and lean those athletes are. They all have body compositions that would make any want-to-be bodybuilder or fitness competitor green with envy, but believe it or not, they do little or no steady-state “cardio” as part of their training.

Unlike all of the people trudging down the road or jogging on the treadmill at your local gym, speed and power athletes are lean and muscular without doing “cardio” in the traditional sense of the word. Yes, those athletes who are naturally lean and muscular do tend to self-select sports where speed and power are a prerequisite, but the level of muscularity coupled with low levels of body fat cannot be attributed to genetics alone.

Speed and power athletes (track sprinters, sprint swimmers, soccer forwards, olympic weightlifters, gymnasts, etc.) obtain extraordinary body compositions by doing primarily interval training and resistance training.

What Exactly is Interval Training?

Interval training is a type of exercise that involves short bursts of high-intensity work immediately followed by lower intensity rest, repeated for a set period of time or number of repetitions. This type of training is typically performed by running or cycling, but can also include many other forms of exercise like swimming, rope jumping, and resistance training.

Interval training is believed to have first been “invented” in 1930’s Europe as a means of improving endurance and speed in track athletes, and is attributed to Germany’s Freiburg University coaching staff.

One of the first landmark studies that showed interval training to be far superior to steady-state cardio training for improving body composition was done in 1994.¹ In that study they found that interval training helped participants lose nine times more body fat than aerobic steady-state training (such as jogging). To drive home the point even further, the interval program in the study was done for only 15 weeks while the aerobic program lasted 20 weeks, showcasing interval training as having potentially even greater results than steady-state cardio.

The main reason researches believed that the intervals resulted in more fat loss in less time is that intervals increased the “after burn”, or the number of calories burned from fat throughout the recovery period, and that the interval group had an improvement in their body’s ability to use fat for fuel, which resulted in greater fat loss. The workout used in the 1994 study initially consisted of 10 sprints of 15 seconds each, and increased to 15 sprints of 30 seconds, initially starting out at 60 percent of maximum and gradually working up to 85 percent of maximum. Recovery times were long enough to allow the heart rate to return to 120-130 beats per minute.

Structuring Your Interval Training

There are many different ways to structure your interval training, and no particular work-to-rest ratio is necessarily the best for every person. Things to consider are your level of fitness, current body composition goals, and experience performing interval training.

One important thing to keep in mind is that the “work” portion of the interval needs to be very challenging and intense to illicit the optimal physiological effects, and the “rest” portion of the interval needs to be easy or moderate to allow for enough recovery to maintain intensity throughout all subsequent repetitions. Think of a wave graph where the difference between the crest (work phase of the interval) and trough (rest phase of the interval) should be significantly different. The tendency, and what you should strive to avoid when doing intervals, is to have the crest and the trough come too close together and become more like continuous training.

Below are the main parameters to work with when designing an interval workout, and it is usually best to only change one parameter at a time as you progress:

1. How long you do each interval (200 meters, 30 seconds, etc.)
2. How fast you perform each interval (80% of full speed, 12 miles per hour, etc.)
3. How long and what fashion you rest/recover between each interval (30 seconds walking, 120 beats per minute jogging, etc.)
4. How many repetitions your are going to complete or total duration of workout

It’s always best to begin an interval training session with a light warm-up of around five minutes where you progressively increase the intensity of the exercise(s) you are going to perform for the training bout. Further, sessions should be concluded with a cool-down and stretching to help the body clear lactic acid and facilitate recovery.

Here are three example interval training workouts for somebody of moderate fitness level who has experience with this style of training:

Example #1 – Track Sprint Workout

• Sprint 400 meters, rest 4 minutes
• Sprint 300 meters, rest 3 minutes
• Sprint 200 meters, rest 2 minutes
• Sprint 100 meters

Example #2 – Pool Swimming Workout

• Swim as fast as you can 10-15 lengths, with 30-60 seconds rest between each length

Example #3 – Cycle/Ergometer Workout

• 5-10 repetitions cycling as fast as you can for 60 seconds at 75-85% max heart rate, resting between each interval for as long as it takes your heart rate to come down to 55-65 max heart rate.

The Bottom Line

Interval training is a great way to work through a fitness plateau, lose body fat while maintaining muscle mass, and add variety to your training. It’s not necessary to perform much, if any, steady-state aerobic “cardio” exercise if your goal is simply to lose fat while maintaining or increasing muscle mass. Just look at speed and power athletes who have been using interval training for decades to improve their performance and maintain their leanness in minimal time, and you’ll quickly see the powerful effects of this type of training.

Interval training has been shown over and over to be a “shortcut” to optimal body composition for those who are willing to put in the short but intense effort. Sprinkle it into your own workout routine a couple times per week and see how it benefits you!

References:

1. http://www.xiser.com/assets/impact_of_exercise_intensity.pdf

About Jeremy Senn

Jeremy Senn MS, CSCS specializes in body fat reduction & muscular power for increased health & physical performance. Jeremy has worked with hundreds of personal training clients and athletes, has a Masters Degree from Southern Oregon University, and has served as an instructor teaching Physiology of Exercise at SOU. Jeremy is published in MSSE ("Risk of Heart Disease in Firefighters").