Cardio: When and How much?

At my in-person facility a lot of people come to us because they want to get stronger. They want to establish an exercise routine and between the group classes, the technical expertise of the coaches, and the strength focused environment, we’ve developed a great program to take someone from never having set foot in a gym to a competent gym goer within 4 months. An in person coach and a group is a great setting to get strong, build some muscle, and create a solid exercise routine. We need all of this in our training, however, if we are training for complete body health, there is one component that it hard to capture in a gym environment and harder to capture in a group environment: low intensity endurance or “zone 2”

If you’re reading this, I likely don’t need to explain the massive list of health benefits of this type of training. Its benefits on the heart, lungs, and mitochondria is unparalleled. Since we are all at different levels of endurance based on genetics and training history, however, what zone 2 cardio looks like for two people, even if those two people are similar weight size and strength, may be completely different. Having everyone work at the same pace for their cardio would be the strength equivalent of having everyone squat 185lb. Some people this would crush, some people it wouldn’t be enough of the right stimulus, because we all have different levels of strength. So how then would we gauge our zone 2 stimulus and make sure we are doing work at the right intensity.

The answer, for those of us who have been around the gym for a while, is simple, we use an RPE scale. RPE or Rate of Perceived exertion was originated for endurance training, and while they used a 0-20 scale, the same principles apply to endurance as they do to strength with 1 being very little effort and 10 being all out. This zone 2 work should be done at an RPE 3-4, or relatively easy. A good gauge is to test if you can hold a conversation while exercising. Someone you are talking to should be able to tell that you are breathing heavier than normal, but you should be able to get out full sentences without broken speech to catch your breath. If you have moved into the modern era of wearables and have the ability to accurately measure your heart rate during exercise, aim for a target HR that is 5-10 BPM below 180-your age. Keep in mind, just as we use a percentage recommendation alongside RPE if lifting, your RPE for cardio should always take precedence over whatever a wearable is telling you. If you're in the right heart rate zone, but you can't breath and the exercise “feels hard” , drop back the pace accordingly. Your body always knows the answer, we just have to quiet the noise and listen.

Zone 2 training is as easy to do as it should feel while you're doing it. The key to starting out is to gradually increase the amount you can tolerate week to week until you’ve reached the upper limit for your schedule or for health benefits. Research into this topic shows that the most cardiovascular and mitochondrial benefit occurs around 180 minutes or 3 hours of this style of training performed weekly. That may seem like a lot, but give yourself 6-8 weeks to build up to this amount of training and you’ll likely feel more recovered from your workouts due to an increased cardiovascular efficiency. When planning these sessions, frequency is more important than duration. It is better to have four 20 minute sessions than one 90 minute session. It is for this reason that I recommend folks start out with 2-3 15-30 minute zone 2 sessions per week. If after 2 weeks, these sessions feel solid and you do not feel any extra fatigue or stress from your training, begin to add 5-10 minutes to 2-3 of the sessions per week. In no time you’ll be up to three 60 minute sessions, right at the maximum benefit window.

We’ve got a solid understanding of what these workouts are supposed to feel like and how much of them we need in a week, that is great, however we still need an actionable plan. How do we implement this into our already busy lives and our already scheduled 3-4 days in the gym doing strength, conditioning, and hypertrophy training? We have a few options depending on your preferences of where, when, and how you’d like to train this quality.

Option 1: Outside the Gym Cardio: This is the most frequently used one by folks who have a prior history of endurance activities. Maybe they liked to cycle or ran cross country or were on the swim team back in the day. These folks benefit from choosing a modality they found fun in the past and scheduling time to do it outside of gym hours. This can be in the morning before work assuming you normally train after work or vice versa if your schedule is opposite. A short workout like  this could also occur during a lunch break, assuming you planned your day accordingly. Keep in mind that being outside does require some equipment like the right shoes or a bike and it carries some more risk of injury than other options. Rolling your ankle on a tree branch during a run a few miles from your house can really mess up your day! If you choose to go outside, plan safe routes to avoid objective hazards. You may also need to consider the weather and time of year for this training. Not everyone loves running outside when it is below freezing. This style often gives you time to yourself, and time outside, which while not included in the benefits of zone 2 training, have great positive mental health benefits.

Option 2: In the Gym Cardio: Some people just like going to the gym. It is the place where you do the thing, so set yourself up to do the thing there. Most gyms have some cardio equipment that can be used for this style of training. Choose one that you are comfortable with, whether it is a treadmill, elliptical, stationary bike, or stairmaster. They all are going to work your aerobic system. These options are great for folks who maybe have an injury history that might prevent them from running. Ellipticals and stair masters have a much lower impact on the joints than running in any form, so these are great options for those people. Getting this training done at the gym, also can be convenient. You're already there 3-4 times a week for your other training, maybe try staying 30 minutes later or getting there 30 minutes early before an easier lifting day to get in a session as you're starting to build up your duration. Keep in mind that as you do this type of training for the first time, doing it directly before a hard strength session might have some negative impact on your ability to lift, especially in the lower body. Even though we are focusing on the aerobic system, we do still have to use our muscles to move!

Option 3: In the Gym, but more fun: Often the biggest complaint I hear about doing this type of training is that it is boring. Sitting on a bike or treadmill, or even going for a jog around the neighborhood can be mind numbingly boring, even with some music or a podcast. Those of us with a background in strength training like the variety that we get from those sessions and we might feel the need to have this same experience in our zone 2 training as well. Luckily, this can be easily done, and with minimal equipment. There are a ton of exercises that can be strung together into innumerable combinations to get an aerobic training effect with “gym style” movements. The keys here are to choose exercises that are unloaded and can be done at a consistent pace. Be mindful of explosive exercises as it is easy for us to over exert on these to push ourselves right out of the correct effort zone. Here are some examples

Ex 1: 30-60 mins: Body weight squat Ladder x 3, 6, 9…30, Step Up x 3 each, x 6, x 9…30, burpee x 1, 2, 3 ….10. This would look like Squat x 3, Step up x 3, Burpee x 1, Squat x 6, Step up x 6, Burpee x 2, continued for 30 mins. If you make it to the top of the ladder, start back down at 3/1 again and build back up

Ex 2: 30-60 mins: 1 minute on 1 minute on. Rower or Assault bike 1 min, Step Up or walking lunge x 1 minute. Alternate between these two exercises for as long as you’d like.

Ex 3 30-60 mins: KB Swing ladder 1-10-1, light forward sled drag between each rung. This would look like KB Swing x 1, Sled Drag, KB Swing x 2, Sled Drag. Make sure to keep the sled light and “be slow” on the swings to prevent an effort spike.

The hardest part of these styles of workouts is making sure we stay in the right effort zone, so be honest about your exertion level, and track your heart rate if needed. We shouldn’t feel these too much in the muscles and we certainly should be able to carry conversation during these efforts. A major benefit of this option is you can set up a workout with a few stations and perform these with some friends! Keeping each other on target with some casual conversation is a great option as well.

Whether you want to hit the open road, get on the treadmill, or set some step up/assault bike circuits in, there is something for everyone who wants to add some aerobic training into their routine. Let’s be honest, anyone who is “training for life” needs to include some of this into their routine, because this style of training is one of the most important for cardiovascular health. So look at your next week of training, and schedule some time to get in a few short sessions. In a few months you’ll be feeling great.

Citations:

1 Maffetone P, Laursen PB. Maximum Aerobic Function: Clinical Relevance, Physiological Underpinnings, and Practical Application. Front Physiol. 2020 Apr 2;11:296. doi: 10.3389/fphys.2020.00296. PMID: 32300310; PMCID: PMC7142223.

2 San-Millán, I., Brooks, G.A. Assessment of Metabolic Flexibility by Means of Measuring Blood Lactate, Fat, and Carbohydrate Oxidation Responses to Exercise in Professional Endurance Athletes and Less-Fit Individuals.Sports Med 48, 467–479 (2018). https://doi.org/10.1007/s40279-017-0751-x