Why You Need Better Aerobic Fitness

If you've read any of my conditioning articles you're probably well aware that I'm a huge proponent of using aerobic work to bridge the gap between our main strength sessions. This has cascade effects such as improving recoverability, work capacity, and keeping stress levels at bay (improving your ability to handle stress over time.)

If you have better aerobic fitness your ability to bring more oxygen and nutrients to skeletal muscle (we develop more capillaries which are like having more roads to reach more surface area) will be higher.

Recovery and repair need oxygen and nutrients to fuel that process. Someone who has more roads can cover more ground faster and improve the whole muscle function.

By having more capillaries “roads” there is a higher ability for waste products (such as lactate) to leave muscle and not impair the recovery process. The whole goal is better delivery and better clearance.

More aerobic fitness also means more mitochondria and therefore more factories to process the oxygen to generate more energy for repair.

“Lifting weights faster” does not replace aerobic conditioning. Here’s why:

The adaptations in the heart are not the same - lifting weights thickens cavity walls whereas cyclical work (running, rowing, biking ect) in the 60-70% (Zone 2) of max heart-rate stretches cavity walls.

Another thing to note, is to maintain the same level of cardiac output (a product of heart-rate and stroke volume which is an important element when improving aerobic fitness) by lifting weights faster for longer durations is simply not sustainable - a key component to getting the most from your aerobic work is that it is somewhat easy and a pace you could sustain for longer durations.

Lastly, when lifting weights, blood pressure rises to maintain muscular contractions. This reduces stroke volume and therefore restricts venous return (blood back to the heart) - this results in your heart-rate increasing which inhibits “stretching” (eccentric hypertrophy in the image shown) and takes away from the results we are going after.

Can you improve qualities like strength-endurance with things like complexes, sure, but the intent takes precedence and if your goal is to improve recovery, work capacity, and how long you live (yea, that’s a big one), then devote time to aerobic conditioning.

If you're interested in learning more about Energy Systems development, check out my Playbook here.

The Aerobic System

The aerobic system provides the majority of the energy production for any activity lasting longer than 60 seconds, regardless of the intensity level. This system is also responsible for recovery between explosive bursts as well as producing the energy necessary to sustain everyday life.

For years aerobic work was frowned upon which would make you slower and gain fat. Of course, knowing what we know now about Energy Systems we know that we can utilize Aerobic work to facilitate recovery, improves our ability to generate ATP for explosive sports, and increase the length of our life.

Why Aerobic Work Is Necessary:

• Research has shown that life expectancy is directly related to aerobic fitness and may help protect against premature death due to cardiovascular disease
• The aerobic system is the most “metabolically adaptable” energy system in that it can produce ATP from multiple energy sources.
• The aerobic system produces more molecules of ATP per molecule of substrate.
• The aerobic system is the most adaptable system when it comes to room for improvement

In short, training the Aerobic System involves two kinds of adaptations: cardiovascular and skeletal muscle.

Among these adaptations include increasing the functional capacity of the heart, increasing the size of the vascular network, and increasing the number of mitochondria and the function of mitochondria.

The Cardiac Output Method

With this method, you may stop reading when you hear the words “low-intensity” or “steady-state,” but as I said before, be open-minded because this is the premier method for improving the aerobic system.

The reasoning is simple: without an efficient aerobic system, your ability to recover between sessions and between working sets will not be what it could be. Moreover, improving your aerobic system can literally extend how long you live.

The connection between aerobic fitness and lifespan is pretty well established, with numerous studies to back it up like this one here. In fact, this method was the single most beneficial method for my own training and took my conditioning to a level I didn’t know existed.

Moreover, if you have better aerobic fitness your ability to bring more oxygen and nutrients to skeletal muscle (we develop more capillaries which are like having more roads to reach more surface area) will be higher.

Recovery and repair need oxygen and nutrients to fuel that process. Someone who has more roads can cover more ground faster and improve the whole muscle function.

By having more capillaries “roads” there is a higher ability for waste products (such as lactate) to leave muscle and not impair the recovery process. The whole goal is better delivery and better clearance.

More aerobic fitness also means more mitochondria and therefore more factories to process the oxygen to generate more energy for repair.

Here are the two primary methods I use to develop aerobic fitness for my clients.

The hardest part for most is that it’s too easy (yes, it’s easy to do), and it can be somewhat boring, but how we customize these sessions while still keeping the intent intact is key.

First off, let’s discuss what cardiac output is. Cardiac output is the amount of blood the heart pumps through the circulatory system in one minute. In layman’s terms, it’s a product of heart rate and stroke volume, so this training style influences the heart’s ability to pump blood to the extremities. More importantly, it can increase the cavity volume known as ‘eccentric hypertrophy,’ particularly of the heart’s left ventricle.

I know what you’re thinking, “Can’t I arrive at these same adaptations by simply lifting weights!?” No, you cannot! The reason is, eccentric hypertrophy (stretching) of cardiac tissue is a result of low-intensity conditioning done for longer durations, and the heart-rate needs to be in a specific range for this to occur.

On the other hand, weight-training results in more of ‘concentric hypertrophy’ of cardiac tissue, which is a thickening of the walls—two very different things. So, improving cardiac output is done in very specific settings with very specific measures.

And no, this type of work will NOT take away from your strength gains when done correctly. Let’s dive right into programming.

Guidelines:

• Select 2-3 pieces of cardio equipment
• Perform 10-20 minutes of steady-state ‘conversational style’ work on each
• Perform 1-2 sessions a week as their own training session
• Heart-rate 60-70% of MHR (Zone 2)

Sample Programming:

• 15 Minutes of Air Bike
  15 Minutes of Rowing Machine
  15 Minutes of Light Sledpull Powerwalk (a weight you can walk continuously with without stopping)
• AMRAP 60:
  50 Double Unders
  40 Calorie Air Bike
  30 Calorie Air Runner or Rower
  20 Hollow Rocks
  10 No Push-up Burpees *If you find your HR gets too high (over 150) after the burpees rest for 60s.
• 10 Rounds of:
  20 Calorie Air Bike
  20 Calorie Rower
  100 Ft. Odd Object Carry
• Calories/Reps of:
  50-40-30-20-10
  Air Runner (or 4:00, 3:00, 2:00, 1:00 run)
  Calorie Air Bike

For most people, 40-60 minutes 2-3x per week is enough, but if you’re already more aerobically inclined, you can go as long as 60-90 minutes.

On the other hand, if you have zero aerobic fitness, start with 20 minutes and progress to 30 minutes over the course of eight weeks. Remember, this work is intended to be ‘easy,’ so if you can’t carry on a conversation while doing it, you’re going too hard!

High-Intensity Intervals

High-Intensity Intervals aim to use a variety of sustainable exercises with incomplete bouts of rest after each round. The intent is to stimulate higher oxygen utilization and improve the aerobic abilities of fast-twitch fibers.

Notice, I used the word “sustainable,” so when we think about movements that can be sustained for longer durations, we are not thinking about using locally demanding movements like a push-up or pull-ups that have high rates of peripheral fatigue. Most trainees will be limited by local muscle endurance, not their overall level of aerobic conditioning.

When we select movements, they need to be movements you could sustain for 30-60s without stopping.

Guidelines:

• Low resistance movements that can be sustained for the entire interval without stopping
• 15-20 minutes in total duration
• Incomplete rest intervals
• 1-2 sessions per week

Sample Programming:

5 Rounds of:

• Air Bike for Calories x 60s
• Russian KB Swings x 60s
• Rowing for Calories x 60s
• Box step-ups (unweighted) x 60s
• Rest x 60s

Of course, you can get creative using different variations, but the key takeaway is that you should have sustained output for all sets, meaning round one should not look much different from the last round. This style of workout will leave you feeling relatively fresh thereafter and with a good sweat!

Again, choose movements that are sustainable for you and allow you to work for a prescribed duration without stopping—this shouldn’t be a brutally hard conditioning piece.

Sled work and Loaded Carry Combo

Clearly, this method will not come as a shocker to many, but there are more than a few caveats with programming this method. In terms of when you do it, do you perform it in a separate session or on a ME or DE lower day?

In this case, the sets’ duration will be longer, and loading will be lower, making this a better fit for its own conditioning session.

On the other hand, these two modalities could be used for anaerobic work using heavier loads for more sets/shorter durations, but that’s another article.

Sled Work and Loaded Carry Combo is a great way to train aerobic abilities of fast-twitch fibers and maintain posture when the heart rate is elevated and when fatigue begins to set in.

Here’s what you need to know:

Guidelines:

• 8-12 sets x 60s-90s & 90s rest between sets
• Or for a set distance of 400-800 meters for time
• 1 session per week

Sample Programming:

• 1a. Sledpush Sprint: 8 x 60 yards. No rest.
• 1b. Crossbody Farmer Carry: 8 x 60 yards. Rest 90s – 2:00

Or

For time:

• 400 Meter Sled Pull Farmer Carry
• 25% BW on Sled (includes sled weight) + 50% of BW (total in each hand)
• Goal is to stop as little as possible
• Shoot for sub 15:00

Learn How To Write Your Own Strength & Conditioning Programs