As the title kinda gives away, this post is mostly about cardio. But there are also cups of tea, World of Warcraft and Navy Seals, so bear with me. (3.600 words, estimated reading time 18-19 min.)
Let’s take a hypothetical situation: you need to start training from scratch. What would you need to know, do right now, plan for the foreseeable future, and beyond that?
Maybe you’ve never trained and you don’t know where to start. Maybe you thought you knew but you’re not getting where you thought you would. Maybe you’re just fine, you’re not second-guessing your training at all, and it’s ‘just for a friend’.
I’m glad you asked, or just considered the question with some interest. Even if it’s only because you paid for it on Patreon. My own interest came from this:
- I’ve known some serious setbacks (you can read my sob story) and I had literally to start over from scratch. Clearing my head from all the fitness bullshit I might have bought into over the years (and inoculate myself to prevent relapse) seemed a good place to start. [2021 EDIT: I’ve unlinked the 2018 sob story because it really wasn’t that bad compared to leukemia, chemo, subsequent detraining, and starting from scratch again. I stand by everything else in that post, though.]
- My kid trusted me to program her training and I didn’t want to betray that trust so I wanted to get things right from the start. Also, I wanted to inoculate her against fitness bullshit.
- I had to coach untrained and detrained adults (and I’ll probably do it again) some of whom suffered from serious cases of fitness bullshit intoxication. Starting from scratch was the best way to cure them and inoculate them against relapse.
Now, don’t expect a training-from-scratch program or specific recommendations yet. Before that, and even if your interest in the question is purely hypothetical, you’re like the university professor from the old zen koan and you need to empty your cup of tea first.
Eventually, there will be a program, it will be science-based, adjustable to particular histories, budget-friendly, etc. But most importantly, you will understand why it is laid down the way it is. That’s what today is all about.
A little knowledge
If you’re training from scratch (whatever the reason) the first thing you’ll need is a well-defined goal; the second, a plan to reach that goal, or at least enough of an outline to specify means; and the third, an incentive to stay on track.
And just because I like to take cheap shots at the marketing techniques of the fitness industry, I’ll give this piece of common sense an acronym and a name: the GPI® formula. It’s not as sexy as MASS® (or™) or CrossFit®, but it reminds me of two things I like (the Gender Parity Index and the Genuine Progress Indicator).
GPI® = Goal + Plan + Incentive
And when I’m tired of being poor and honest, I’ll register it for real and sell a 20 hrs course about it as part of the Analytic Fitness™ Certification. But today, I’ll stick to the crash course.
Knowledge implies action.
Etienne Njagi Steward
Now, I’m not into motivational crap. As you must have guessed, I’m more into Zen crap. But I understand the need, so I’ll compromise, and quote my favorite Zen poet-warrior, Etienne Njagi Steward: “Knowledge implies action”. That’s a motivational quote for those who need it, but it’s also true. In fact, the right amount of relevant knowledge can give you all the fitness goals and incentives you’ll ever need. And a good chunk of the plan, too.
To be honest, I think a lot of people muddle the issue of fitness goals, but let’s not get side-tracked. Without further ado, I give you the only piece of knowledge relevant to starting from scratch, namely this diagram:
In order to understand it, you need to know 3 things: (1) what a Hazard Ratio is; (2) what the hours/day on the bottom line are hours/day of; and: (3) what the MET scale is. Can you take a guess?
Here’s a hint: I pulled that diagram from a meta-analysis published by The Lancet in 2016 titled Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality?
And like that, your guess has just been educated.
Everybody should read that study. It’s an eye-opener. But it’s also 9 pages on 2 columns and it’s a little short on exercise recommendations. Since I’ll have to spell the consequences out for training I might as well save you some reading. So here we go.
The Hazard Ratio (HR)
Hazard Ratio is a concept from the branch of statistics called survival analysis. To be honest, I had never heard of it until recently. So if you have, and you think I’m mistaken, please suggest edits. You don’t even have to be nice.
Otherwise, you can read the Wikipedia entry, it’s fascinating and the topic is wider than you think. (Trigger warning: a lot of it is about death.) Cornell University also has a summary for statistically-savvy people.
Simplifying a lot (but I hope that’s okay in that case) let’s say that you want to compare risks of death in two populations, A (the reference) and B, for a given period of time. You take the death rate of A during a period of equivalent length, normalize it to 1, and normalize the death rate of B over that period relative to that ‘1’. That’s your HRs for A and B. If the HR of B is higher than 1, a member of B is at a higher risk than a member of A.
Now, from the diagram above, you can see that the HR for all populations that total more than 4 hrs/day and less than 35.5 MET are higher than 1 (from 1.08 to 1.59, to be precise). So the guys at the extreme right have an HR of 1.59 which amounts to a 59% higher risk of death during the period under consideration than the guys at the extreme left (the general formula is: 1.x amounts to (10*x)%).
Hours/day of what?
By now, this should be a rhetorical question. We’re obviously talking about hours of sitting. But I’m about to add something else to the conversation.
At the end of the day, what really matters is the metabolic cost of what you do (I’ll come to that soon). And since the metabolic cost of standing at a desk is the same as the metabolic cost of sitting at a desk, you might as well count hours of standing at a desk (counter, cash register, etc.) as well.
This doesn’t mean that spending money on ergonomics and standing desks is worthless. It just means that from a physical activity standpoint, standing at a desk is just as effective as watching a YouTube training video. And it will have the same effect on your HR.
The MET scale
Gym rats measure intensity by how much they sweat. Gym bros, by how close to their max weight/reps they lift. CrossFit® addicts, by a formula that proves that everybody else is wrong about the need for good technique, how high you should swing a kettlebell, life, the universe, and everything (but it’s bullshit).
Everybody else uses the MET scale. Especially gals and guys carrying out survival analysis for stuff like advising policy-makers or allocating public resources to public health-care and welfare system (in countries where there’s such a thing).
So even if it’s not your favorite metrics for gains, bear with me. It’s not as fun, but it’s still pretty important stuff.
MET stands for Metabolic Equivalent of Task. A value of 1 on the MET scale corresponds to 1 kcal per kg (of bodyweight) per hour and is roughly equivalent to the metabolic cost of sitting quietly for one hour (which is quite ironic, when you think of it). The MET acknowledges only 3 intensities:
- Low-intensity physical activity (MET≤3): walking at the kind of speed people go at when they shop, commute, or walk around the house (3 km/h), or biking at the kind of speed they go at when they commute.
- Moderate-intensity physical activity (3<MET≤6): anything from brisk walking (5.5 km/h or more) or leisure biking at 16 km/h (both MET 5); or walking slower than that but carrying an additional load of 10-20% of one’s bodyweight (under 20 kg for most people).
- Vigorous physical activity (6<MET): everything more demanding than the above, like sprinting or bicycle racing, but also rucking when carrying an additional load above 25% of one’s bodyweight (more than 20 kg for most people) or even hiking if you climb enough hills and your backpack is heavy enough.
MET values can be accrued and are often specified as MET-hours (MET-h) over a given period and sometimes as MET-minutes (divide by 60 and you get the MET-h). I’ll get back to that. But first I need to get something out of the way.
That something concerns only people who already train and may
have bought into some bullshit retain some misconception about fitness. If you think that there’s a kernel of truth in the meme below, read on.
Otherwise, feel free to skip the aside.
Isn’t strength training ‘vigorous’? You may have noticed that almost every activity referred to above falls into the ‘cardio’ category. But if you look at MET scale tables, you will find that calisthenics is sometimes counted as vigorous physical activity, and so is carrying loads over 20 kg (above 20% of body weight for most people). Shouldn’t bench-pressing 100 kg be 5 times as vigorous as carrying 20 kg? Nope. The metabolic cost of bench-pressing 100 kg is high, for the 5-30′ it takes to complete a set of low reps (remember, we’re talking strength here). And then, it drops down to low for the 3-5 minutes of sitting on your ass between sets. With that ratio of work/rest, strength training averages out to ‘low intensity’.
What about high reps for cardio then? Well, sorry, it’s a nice meme, but it’s bullshit. The short story is this: every time you brace (or more precisely, use the Valsalva maneuver) you forfeit cardiovascular adaptations. Unless you maintain anatomical breathing, there is no ‘cardio’ effect from high reps, and there are very few lifting scenarios where it’s okay to breathe anatomically while lifting weights. And when it is, the weight is too light to cause strength adaptations (unless you are detrained). For a longer story, check Alex Viada’s The Hybrid Athlete. I’ll return to the topic in future posts.
There are some advanced strategies that turn lifting into cardio. But they are not what you think. Essentially, they turn your rest periods into cardio. They are also pretty advanced, very strenuous, and almost always leave your strength and power at the bottom of a bottomless pit. Like Grit™ Strength would if you are not an untrained adult. (For those who live in blissful ignorance of mainstream fitness fads: picture something like CrossFit® but a little less scary, designed for conventional gyms instead of ‘boxes’, and that actually sponsors exercise scientists to test if it’s any good. That’s Grit®.) And in case you wonder, it’s not just ‘shorter rest periods. Actually, if you wonder at all, you’re not using those techniques, so move on. Otherwise, you have my blessing to count the fraction of gym time you spend using these techniques as vigorous physical activity, somewhere around 7 MET.
Exploiting the MET scale
We are now halfway to have an incentive for training from scratch.
Halfway only, because “eliminating the detrimental association of sitting time with mortality” is only half of the picture. In fact, life expectancy is only half of the picture. But it’s a pretty big deal, so it’s worth spending some time on it.
The relation between life expectancy and fitness is really straightforward. As we’ll soon find out, the range of options to increase your life expectancy through exercise is quite narrow. But how do we get that range? Well, it amounts pretty much to milking the MET scale. It’s not exactly rocket science but there are some pitfalls we might want to avoid, so let’s start with that, shall we.
Conan Hackerman do?
When I said earlier that METs may be accrued over time, I meant that you can set a ‘bulk’ MET goal for a given period of time, and chip off that total one bout of physical activity at a time. That’s how the Lancet study gives you the arithmetic needed for goal-setting.
Say that you need at least 35.5 MET-h per week to completely eliminate the effect of up to 8 hours of sitting per day. That’s an average of 5 MET-h/day over a week. It could be:
- 1h of walking at 5.5 km/h (5 MET) every day on a treadmill or with a GPS (because 5.5 km/h is pretty tough so you want to have some feedback to keep the pace). For your information, it was the pace the Roman legions walked at. With 25kg of equipment.
- 1/2h of girevoy (8-10 MET, I’m not kidding, you’ll know if you tried) every day or 1h of girevoy every other day and some moving around on rest days. Or half-an-hour of loaded march every day is you’re a Roman legionnaire who sits on his ass at the camp.
There is, however, a limit to that kind of thinking. To see that, let’s answer that: what would Hackerman do?
Yup. But nope.
Why wouldn’t that work? Because unfortunately for Hackerman, although the MET scale is continuous, there’s a cut-off around 3 MET when it comes to health benefits. Simply put, anything under 3 MET doesn’t count against your weekly total.
Even Hackerman could not hack his way into physical activity with WoW, GW2, or DotA. Even with AoC (although seeing all those athletic types might motivate you a bit). If you’re pulling off all-nighters with MMORPGs, you’ll have to earn it. My daughter and I do that on occasion, but we average around 50+ MET-h/week so we’re off the hook.
So, Cardio or… Cardio?
So far the science seems to back two options for starting from scratch: moderate-intensity cardio, or vigorous-intensity cardio. But actually, there are three options: moderate-intensity cardio, vigorous-intensity cardio, or any combination thereof.
But there’s cardio and cardio. For instance, what about anaerobic cardio? Like sprinting, high-intensity interval training, high-repetition weight training, CrossFit®, etc.? Well, here’s the thing: cardio-respiratory capacity is a predictor of longevity. Which is another way to say that the only thing that matters when it comes to avoiding premature death is aerobic fitness. So, anaerobic fitness is useful in that department only insofar as it contributes to improving aerobic fitness.
Where does that come from? Well, from a recent (March 2018) review published in Frontiers in Bioscience, and titled: Survival of the fittest: VO2max, a key predictor of longevity? If you read the study (as I did) you’ll find out that the titular question is rhetorical: VO2max is the strongest independent predictor of longevity. And it’s a measure of… [cue the drums] cardio-respiratory fitness (CRF). This study adds some bells and whistles to aerobic cardio though, and I’ll have to come back to it in another post. Below is a quick run-down for the case you’d follow the link and skim through the study. Otherwise, you can skip the aside.
What about METs? The authors of the Frontier… review recommend 500-1000 MET-minutes/week (section 5.4, p. 1509). Before you strain your brain with sexagesimal arithmetic, that’s 8-16 MET-h/week. Don’t start to celebrate tho. The Frontier… study is more recent than the Lancet‘s, but the authors don’t reference it. In fact, they are just re-hashing recommendations from an ACSM position paper from 2007. Their figures are not lower because they know something that you don’t, but because they don’t know something that you do.
What about strength? The Frontier… study also points at interesting stuff about other predictors of longevity, like grip strength (“poor handgrip strength has been linked to premature mortality, and this association tended to be stronger in women” (p. 1509)). But in fact, grip strength is statistically non-independent of CRF: knowing CRF ‘screens off’ grip strength, because the predictive value of the latter is correlated with CRF. Now, why the hell would the predicting value of grip strength be correlated with the predicting value of CRF? They don’t say. I have some hypotheses, but I’ll keep them for the next post. For now, the general take-home message is that strength has little independent value for predicting life expectancy. [Edit: This paragraph has been edited out: VO2max is the strongest predictor of all-cause mortality, but strength (and grip strength in particular) is independent of it. I’ll cover that in part II]
Now, even if you did not read the aside, just look at the highlighted sentence. Does it mean that you should not consider strength training? Nope. And I’ll conclude on that (for today) in a minute. But first, here’s all the motivation you should ever need to exercise, in one nice graph. (There is also a hi-res version my patrons can download).
Details about the HIIT (high-intensity interval training) vs. LISS (low-intensity steady state) will come later in the series, but ‘low-intensity’ is not MET-low, but heart-rate/VO2max low (around 60-70%, at the high-end of MET-moderate). Why should you combine them? That will come in due time, but there are some hints in my post about the Tabata study.
A Problem with Cardio?
There is a problem with cardio, however.
In order to improve our CRF, our body needs to build the delivery system (heart and blood vessels). This process is anabolic: we synthesize proteins that make up our heart muscle and the blood vessel linings. Anabolism requires a steady supply of resources: the building blocks of protein (amino acids) and some energy for moving them around.
All our energy comes from food. Either directly, or through stores we build through other anabolic processes, for lean days (pun intended: most of it is fat, and yes, it means that building fat stores is part of anabolism). Our body is very efficient at breaking down stores into simpler molecules to be used as building blocks, releasing energy in the process. It’s called catabolism and our body uses catabolism to fuel anabolism.
That’s metabolism 101. That’s why we are so efficient at building fat stores with anything that’s not immediately useful to move or build body parts Also, why exercise is great for fat loss only if you are in a calorie deficit (but that’s another story). Fat stores catabolism fuels long-duration effort (‘cardio’) but its building-block by-product is fatty acids and fatty acids are not amino acids (duh).
So if you’re doing a lot of cardio, fat metabolism is not going to cut it (pun intended, bros): it provides with the energy to move around, but not with the building blocks for growing the delivery system. But you can still improve the efficiency of the delivery system without having to grow it, just by paying maintenance costs.
Does that sound too good to be true? Well, it is, because the maintenance costs are going to be paid on your own amino acid stores. You guess where I’m headed, don’t you? If you don’t, here’s another nugget of metabolic gold: the efficiency of the delivery system increases if it doesn’t change but the amount of tissue to deliver oxygen to decreases. And that tissue is where your stores of amino acids are located.
So your body has a double incentive to cannibalize amino acids stores to pay the maintenance costs of the delivery system when you do your cardio. Now, I can almost picture some of you jumping around, screaming at the top of their (no-cardio) lungs “I told you so! Cardio will kill my gains!”
As much as I’d like to raise the bar (pun intended, but it’s really used up) it’s not necessary. First, there’s a reality check.
And second, there’s an argument, which is even better: none of the above matters if your body needs the muscle mass to work in synergy with the delivery system, in which case it will simply make you hungrier and pay the maintenance costs for both from food. So, if you’re doing cardio right and it catabolizes your muscles, it’s your fault. You’re just not eating enough. (Or maybe, not enough of the right food, but that’s for a follow-up.)
Now, because real-life is better than memes, and because an example is always good to support a general argument, here is how you can stimulate the muscles and the cardiovascular system in one go. But don’t try this at home. Yet.
Conclusion (for today)
When it comes to fitness goals, there are basically three kinds of people: those who muddle the issue, those who miss the point, and those who don’t give a shit and do what they have to.
In the first category are those who exercise because they think it’s fun, or because they want to look good naked, or because they want the rest of the world to think that they are the strongest, the fastest, or the best all-around gym exerciser on Earth.
And that is absolutely okay. There’s nothing wrong with that or with screaming from the rooftops and/or posting on Instagram, Facebook, or whatnot, to try and motivate other people to develop the same interests.
But the emphasis on positive motivators encourages the notion that, would you lack them all, there would be nothing wrong with not exercising, misleading so many people who end up in the second category.
The third category is made up of people who know that there’s only one scenario in which there’s really nothing wrong with not exercising: if you don’t care whether you’ll live to the end of your natural life or die early. So they don’t give a shit and do what they have to.
And so, they do their cardio.
^ You can read it for free if you register with The Lancet and if you do not want to for some reason you can Google Scholar it and read a preprint of it.
My Patreon supporters at level Gourmet or higher have it in the Info Dump.