Anaerobic Training: How to Suffer Efficiently in the Anaerobic Zone

Anaerobic literally means "without oxygen," so you can imagine how comfy that feels when you're busting a gut on an air bike or tread. Yes, it feels awful, but a couple of short, hard sessions like this each week can build your speed and heart health and help you lose body fat in a lot less time than a long, slow jog.

What Are Anaerobic Exercises?

Anaerobic exercises are short, intense bursts fueled by energy stored right inside your muscles, since your heart and lungs can't deliver oxygen fast enough to keep up. For about 10 seconds you run on phosphocreatine (a fast-acting fuel your muscles keep on hand), and then your body quickly burns through carbs until waste products pile up and you can't maintain the intensity anymore. Good examples of anaerobic exercises are sprints, hill runs, jump squats, heavy lifts, sled pushes, and most HIIT (high-intensity interval training).

The Difference Between Aerobic and Anaerobic Training

Aerobic exercise is anything easy enough that you can keep going for a long time, like jogging or a brisk walk, since your body has time to use oxygen for fuel. You use the aerobic system whenever you do anaerobic training while amping up to that higher intensity, or coming back down from it.

Read More: Cardio vs. Strength Training

What Is the Anaerobic Zone?

The anaerobic zone is also known as heart rate zones 4 and 5, or about 80% to 100% of your max heart rate (220 minus your age gives you a ballpark max, though it's pretty far off for some people). Zone 4 feels hard but still manageable for a few minutes, and zone 5 is all-out max effort that you can only sustain for a few seconds, up to a minute or two, depending on your conditioning.

One thing to be aware of is your heart rate lags behind your effort somewhat, so your watch might never pass zone 3 during a 10-second sprint even though your muscles are fully anaerobic. For short sprints, just go by feel instead of watching your heart rate, and if you can't get out more than one or two words, then you've arrived.

Who Should Do Anaerobic Fitness Training

Anaerobic fitness training is worth doing for most people who already exercise, especially lifters who want better conditioning but don't want to cut into their strength training time with long cardio sessions. Runners and other endurance athletes should definitely do anaerobic training, since they'll need to rely on their anaerobic system for going up hills or speeding up to pass someone at the finish. If you're completely untrained, then you'll want to build a base with easier cardio for a few weeks first. Talk to your doctor before going all-out if you have a heart condition or high blood pressure.

Benefits of Anaerobic Training

Here are some of the benefits of regular anaerobic training:

• Lowers blood pressure and resting heart rate
• Improves blood fats and insulin levels
• Raises your VO2 max (the most oxygen your body can use during hard exercise and a big marker of overall fitness)
• Short sprints of 10 seconds or less build your anaerobic power and aerobic fitness at the same time
• Reduces body fat while adding a bit of lean mass
• Squat-based intervals improve cardio fitness as much as bike intervals while building a stronger squat

Anaerobic Exercise and Fat Loss

Anaerobic efforts run mostly on carbs, and they still help you lose body fat, but interval training tends to show a bit of an edge for reducing waist size and body fat percentage compared with other workout styles. It also trains your body to burn more fat during exercise the longer you stick with it.

However, compared with steady-state (aerobic) cardio, there's not a huge difference. Some reviews call it a tie, and others give intervals a slight edge, so the biggest actual benefit of anaerobic exercise is the time you save. HIIT gets similar body composition results in about 40% less training time, and sprint intervals match HIIT's fat loss in about half the time.

Running-based intervals cut the most body fat, and the ideal amount is a minimum of three sessions per week for more than eight weeks. You can still get benefits from small doses of anaerobic training, but they'll mostly boost fitness rather than cut much fat.

Your eating habits still carry a lot of weight here (pun intended), so be sure to align them with your goals or else you'll likely spin your wheels.

Read More: The Truth About Fasted Cardio For Fat Burning

How to Build an Anaerobic Workout

• Match your rest to your effort. Warm up for five to 10 minutes, then rest about a minute after sprints of 10 seconds or less and two to four minutes after 20- to 30-second efforts (skimp on rest and your sprints turn into a sad jog).
• Keep hard days to two or three a week. Anaerobic work is stressful (the good kind, mostly), so keep the rest of your cardio easy and give your body time to recover before the next one.
• Fuel your repeat efforts. Creatine improves high-intensity performance and recovery, so a daily scoop of Purist® Creatine Plus can help you hold your power through those last few intervals.

Read More: Low-Impact Cardio Workout

Anaerobic Cardio Workouts to Try

Air Bike Sprints

The REP® Strive™ Air Bike featuring VPR™ lets you change resistance by adjusting the fan blade angle, so you can go hard at a 7 or 8 or keep it easier at 4 to 6.

Try eight rounds of 10 seconds all-out, with 50 seconds of easy pedaling (the console connects to ANT+ heart rate monitors if you want to keep an eye on your heart rate zones).

Treadmill Sprints and Sled Pushes

The Strive™ Curved Treadmill runs without a motor and flips into sled mode with eight resistance levels, up to 550 lbs. on the flat deck.

Do six 20-second sprints with two minutes of walking after each, then stop the belt, switch to sled mode, and hit four 15-second pushes with two minutes of rest between them. Our HIIT treadmill workout is another good option.

At-Home Anaerobic Circuit

All you need at home is a kettlebell, a jump rope, and some floor space. Go hard for 20 seconds, rest for 40, and move to the next exercise, repeating the whole circuit three or four times.

• Jump squats
• Kettlebell swings
• Burpees
• Fast jump rope
• Mountain climbers

Pro Tip: Do fast step-ups instead of jumps if your knees are not having it.

Takeaway

Two or three short, hard sessions a week in heart rate zones 4 and 5 can build your speed and heart health and cut body fat in less time than steady cardio. Take rests that are long enough so you can go hard again, and be sure to recover before putting another super intense workout into your week.

FAQs

What are the benefits of anaerobic interval training?

Anaerobic interval training raises your VO2 max, lowers blood pressure and resting heart rate, and builds speed and power. It can also reduce body fat and waist size about as well as longer steady cardio, in less time.

What are some effective anaerobic exercises I can do at home?

Jump squats, burpees, mountain climbers, kettlebell swings, jump rope, and stair or hill sprints all work well as anaerobic exercises at home. Go as hard as you can for 10 to 30 seconds, then rest long enough that you can repeat the same effort. Circuit-style strength workouts with short rests also improve body composition, strength, and cardio fitness, so fast dumbbell thrusters and goblet squats are also good candidates.

Is anaerobic training good for runners?

Yes, anaerobic training helps runners and other endurance athletes surge up hills, kick at the finish, and raise their VO2 max. Hill sprints, short track repeats, and zone 4 tempo intervals are the go-to options. Keep hard sessions to two or three per week and run most of your miles at an easy, conversational pace.