Does Zone 2 Cardio Matter? Benefits of Low-Intensity Training

The significance of Zone 2 cardio has picked up steam in recent years thanks to a combination of influencers and professional athletes who pushed the idea that training at low intensity is physically beneficial, and also of tremendous long-term benefit. In several cases, people have gone so far as to say that Zone 2 training is really all you need to do from a cardiovascular standpoint if you want to be functionally healthy.

Obviously the recognition that you’re training at the second lowest of the five acknowledged cardio zones begs the question of whether or not there are some unlockable benefits at the higher zones that aren’t attainable by remaining in Zone 2. Therefore, a second question should be asked: Does Zone 2 cardio really matter, and even if it matters, is it necessary?

What is it about Zone 2 cardio that is so special?

Specifically, Zone 2 cardio refers to exercise that transpires within the range of 60 to 70 percent of your maximum heart rate, and that is commonly described as “easy” or “light” in intensity. For most people, this level of exercise is typified by movements like brisk walking, slow jogging, relaxed biking, or calm and steady rowing. During a Zone 2 workout, you would expect to be able to carry on a conversation with little difficulty.

Zone 2 cardio can extend for well over an hour for most healthy people, which is helpful because it is a comfortable way to burn extra calories. Internally, Zone 2 cardio also strengthens your aerobic system, helps your body to burn fat for energy, and also improves your insulin sensitivity. 

The bottom line is that Zone 2 cardio checks all of the boxes required for everyday people to achieve cardiovascular health without any of the discomfort associated with harder levels of training.

Can Zone 2 cardio’s benefits be achieved through training in other zones?

Most of the benefits that are achievable through Zone 2 cardio are also achievable through training in the higher zones, and potentially with a higher upside depending on what your personal goals are. 

By picking up the pace of your training just a little bit, you’ll enter Zone 3, where you’ll elevate your aerobic endurance and cardiovascular efficiency to an even greater degree. On top of that, you’ll also make meaningful improvements to your muscular endurance.

Pragmatically, if you wish to make a good-faith effort of participating in any endurance running events, or in other race-based competitions, even if it’s only a 5K run (3 miles) or 1,500-meter swim, you must complete a significant portion of your training in Zone 3. That way, you’ll actually be able to pick up your pace and won’t be stuck in the lowest gear the entire time.

In the higher zones, you’ll be treading into training territory that will enable you to build the type of speed, power, and energy efficiency required for completing the best possible sprint-based efforts. This is especially true of Zone 5, which is the essence of HIIT sessions, where you’re required to expend every ounce of energy you can for a short period of time. 

At this high effort level, you’ll primarily be building your anaerobic capacity rather than your aerobic capacity. Even so, evidence shows that anaerobic training produces effects similar to those of aerobic training, even if the output is less sustainable. 

So are zones overblown?

The discussion of Zone 2 cardio can be used to explore what it means to be physically well-rounded, and also the danger of failing to recognize what you have actually been preparing your body to do during training. 

If you regularly indulge in Zone 2 cardio, you should expect to shed calories, burn fat, improve your body composition, and improve the health of your heart. For many people, this represents everything they ever needed out of cardio, and they have no reason to venture outside of Zone 2. 

Moreover, Zone 2 cardio can help people of any age fulfill the American Heart Association’s weekly recommendation for aerobic activity, which is 150 minutes per week. Again, the secondary benefit here is that this goal can be achieved with minimal stress to muscles or joints. In essence, as you progress in age, Zone 2 cardio will grow in its appeal, as cardio in the higher zones become more challenging to sustain.

For the time being, however, if the mood suddenly strikes you to play a game of backyard football, or join a softball league and have to sprint to beat out a throw to first base, or especially if you decide to enter a local 5K charity run, you might be shocked by how little Zone 2 cardio has prepared you to perform any of these tasks. What’s more, your sudden need to deliver an all-out effort might leave your muscles very sore, and might even result in an injury.

Balance your zones

In order to achieve a well-rounded semblance of fitness, it is in your best interest to spread your cardiovascular activity across the full range of training zones. Spending time in each will leave you with a body that is extremely fit, and is prepared to tackle any challenge. As for whether or not Zone 2 cardio matters, the answer is undoubtedly yes, but there’s not need to spend all of your time in Zone 2 when there’s value to training your way through all of the other zones as well.

Summary

1. Zone 2 cardio became popular through promotion by social media influencers and professional athletes.

2. In essence, Zone 2 cardio is low-impact cardio that is easy on joints, helps the body burn fat efficiently, and can be continued for an extended period of time.

3. Practically speaking, Zone 2 cardio is the easiest way to achieve the weekly training recommendation of the American Heart Association.

4. Cardio in Zone 3, 4, and 5 can produce similar benefits to Zone 2, along with improving muscular endurance and anaerobic capacity, making it ideal for people competing in sports.

5. In addition, cardio in Zones 3-5 also produces similar aerobic effects as Zone 2, albeit at a greater physical toll.

6. To build a tolerance for cardio at all effort levels, you are advised to schedule workouts in all cardio zones so that you are physically and mentally equipped to handle training at any difficulty or duration.