If you’ve missed the past couple tips or are just tuning in, today’s tip is part three in a brief discussion of “cardio training” (cardio, for short).
In part one, I covered heart rate zones and what cardio does and doesn’t do (weight loss, perhaps surprisingly, being in the category of what it doesn’t exactly do).
In part two, we looked at the body’s energy systems, the transactional approach to cardio, and why it’s minimally effective for weight management.
Today I’ll tie those ideas together, offer a high-level template for effective cardio work (for a variety of benefits), and hopefully clear up any potential confusion. Let’s get to it.
Transactional vs. structural
Last week I stated that the transactional approach to cardio for weight management does work, but it’s error prone, slow, inefficient, and often unsustainable. By transactional, I mean trying to balance “calories in” with “calories out” and ending up at a deficit in order to produce fat loss. (By the way, focusing purely on “getting in the mileage/time”, as opposed to varying pace and heart rate, is the transactional cardio approach for racing events.)
Then I suggested that a structural approach to cardio is a better option and teased how it relates to M&Ms. While I hate to disappoint, I don’t mean the “candy-coated chocolates” in this case but rather “Muscles & Mitochondria”.
In other words, a structural approach to cardio means using specific training strategies to produce adaptations to our muscles and mitochondria and experiencing fat loss and improvements to strength, power, and endurance as byproducts.
To understand why this is a better approach and what it means for practical application, you need to understand what mitochondria are as well as two specific characteristics of muscles. Here are some simple analogies:
Mitochondria
These are the energy factories of cells. They’re basically the structures that take in fuel and release energy that the cell then uses to “do stuff”. Producing more of these structures and making them more efficient leads to better overall health and endurance.
Muscle
Characteristic #1: What most people typically think of as a muscle—the biceps on the front of the upper arm, for example—is actually composed of groups of muscle fibers. Moving faster or lifting a heavier weight requires more of those groups to be activated as compared to moving slower or lifting a lighter weight, relative to your abilities. That’s muscle-characteristic #1.
Characteristic #2: Each group of those fibers is like a non-dimmable light: all of its composite fibers are either on or off. So if you want more light—that is, to move faster or lift heavier — more groups are activated. If you want less light—that is, to move slower or lift lighter — fewer groups are activated.
Varying movement speed, weight lifted, and work-to-rest ratios during cardio work recruits different quantities of muscle groups and employs different energy systems. That leads to our desired mitochondrial adaptations as well as muscular strength, power, and endurance capabilities and body composition adaptations (assuming you’re following a decent nutritional protocol).
Cardio methods and uses
So what does this look like in practice? And how is it different than HIIT?
HIIT—High Intensity Interval Training
First, “high intensity interval training” is a misnomer. It’s actually moderate intensity (i.e. weight), high-density (i.e. more reps per time period) interval training. That distinction is important because of the resulting muscle activation and energy system dynamics.
HIIT is usually structured as a circuit of one or a few exercises, often lifted somewhat quickly, with incomplete recovery periods between exercises and/or subsequent circuits. This usually results in the glycolytic energy system being used throughout much of the training (see last week’s tip for details).
While that leads to some quick progress to strength, endurance, and often body composition, progress slows or stalls after a few weeks. In the short term, it’s an excellent strategy to peak for a specific event (e.g. Spartan race, marathon, triathlon, beach vacation). But in the long term, the body struggles to recover from subsequent training sessions, and the very real probability of stagnation, overtraining, and regression increases.
To solve this problem in our structural approach, we need to train using two different types of sessions.
LSD—Long, Slow Distance
The first type of session is what you probably consider traditional cardio: long, slow distance. Pick an activity like hiking, jogging, biking, swimming, dancing, yard work, or any other low-intensity option, and go for 1-3 hours at an easy, steady pace. (Thirty minutes or less is OK, especially if you’re just starting out or are low on time. But longer is generally better.)
The point of this type of session is not burning a bunch of calories but rather improving the efficiency of the mitochondria. For best results, aim to breathe through your nose or chat with a friend the entire session. Or, if you’re wearing a heart rate monitor, stay near the top of zone 2 (i.e. less than 70% of your max).
PR—Power Repeats
The second type of session is likely new to you unless you train at TNT (or similar gym) or if you follow StrongFirst or other mainstream fitness “deviants” (← said purely with love & respect): power repeats.
In this type of session, you’ll be using some type of explosive movement(s): kettlebell swings or snatches, medicine ball throws, skiers/rowers, box jumps, jerks, sprinting (on foot or a bike), or another similar activity.
There are three primary differences between this type of session and HIIT:
- Reps are lower, usually in the 3-6 range. For activities like sprinting, less than 8-10 seconds is best.
- Weight, if used, is often heavier. However, you still need to move it fairly quickly. (Remember that both heavier weight and faster speed recruit more groups of muscle fibers.)
- Rest periods allow for complete or near-complete recovery.
These dynamics mean that you’ll mostly be alternating between the alactic energy system (when moving) and the aerobic system (when resting). Accordingly, you’ll eventually be out of breath immediately after completing a work set (heart rate in zone 3 to high zone 4). But you should be able to easily carry on a conversation by the end of the rest period (heart rate back into zone 2).
In any case, carry on for 30-60 minutes, until just before your power/speed drops noticeably, or you’re still breathing heavily by the end of your rest period. And, again, the point of this session is not to burn calories (although you certainly will). The long term, structural outcomes include the development of more mitochondria, the ability to move and produce force quickly (speed and power, respectively), and potentially a modest increase in strength.
All of those benefits will help you to move faster during a race, improve your general health and have more endurance for daily tasks, or, if you’re following a reasonable nutrition program, drop a few pounds.
Putting it into practice
Unless your goals revolve around pure strength development (i.e. Olympic or powerlifting), adding one session per week of both LSD and PR to your training regimen will produce a variety of positive results.
If you’re looking for a little more, try the following: PR x 2/week, LSD x 1/week, strength-focused training x 1-3/week, and a day or two of rest.
My only other suggestion is to pick something that you enjoy for your LSD work. In most people’s opinions, it’s typically the most boring of the three protocols. So if you opt for an activity you enjoy, you’re much more likely to do it!
And in the long term, another benefit of all of that activity could be helping you feel less anxious about enjoying the occasional package of actual M&Ms. 😉