By Jordan Smothermon
We start our endurance cycle this week and it’s built around a couple of central ideas.
1. Make your “slow” fast.
2. Increase continuous time under load without rest.
We started training endurance as a cycle in the first place because one of the primary fitness attributes of a vast majority of military athletes is having the ability to move over ground under load, continuously, at pace. This idea essentially illustrates that many aspects of military athletes’ jobs largely rely on endurance with high strength, power, and work capacity demands – that they need to be able to repeat for long days back to back – and the importance of each could change mission to mission.
Those are myriad, variable attributes to build into one athlete. So, our training is myriad and variable; and our training does not rely on the staid training practices of particular category of sports. Rather, we draw from the deep pool of data and practices of many training applications and modes – with necessary innovations from our experience and your feedback along the way (of course, we make mistakes, too).
One of those training applications is endurance sports. Endurance sports probably have the richest trove of scientific data to sift through – both a blessing and a curse. One of the primary themes of endurance training is building and maintaining an aerobic base – a nebulous term, written about ad nauseam and argued about endlessly, which has led to its muddled meaning and confused importance. Nevertheless, the best and most successful endurance athletes and coaches in the world always start with building a “base.”
So what is an aerobic base? It is, in a sentence, your mode-specific (e.g. running, cycling, swimming, rucking) ability to move at a sustainable pace for an extended period of time. How much time? Andrew Coggan and Joe Friel, two leading minds in endurance training, say 4 hours. That’s our time standard as well.
Base, then, in many ways is slow, consistent movement. In order to make your “slow” fast, you have to train at a low intensity.
“Slow,” however, is really an inaccurate term. Your base pace shouldn’t be slow, but rather easy.
Steve House, the world-renown alpinist and author of the recent book Training for the New Alpinism says the term, “Long, Slow Distance (LSD) should be replaced with Long, Easy Distance.” The better your aerobic base is, the more efficiently you move, so the faster you move with the same energy output. A well-trained base isn’t slow.
In this cycle, when we say easy to moderate pace, we’re building your base. Stick to that low intensity. House (and he’s not the only one to say this) goes on to say that the biggest problem with most athletes’ training is their easy days aren’t easy enough and their hard days aren’t hard enough. Everything falls into the valley of moderate intensity, which leads to you never getting the benefits of easy training, which leads to never really being rested, which leads to being too fatigued to really go hard and get the benefits of hard training. It’s a landscape of immediate, steep gains and long plateaus into a distant horizon.
What are the benefits of base training? Twofold. First, base training increases mitochondrial density in your muscle cells. Mitochondria are the power factories that increase your ability to metabolize fat, the primary source of energy at low intensity.
Second, it increases the formation of capillaries in your muscles. The more and deeper your capillaries go, the better they are at delivering oxygen to your muscles. These are crucial adaptations that take time to build. And they simply do not happen at high intensities.
In fact, athletes that almost exclusively train at high intensity have such a small aerobic base that, oftentimes, their body will push them to move fast, increasing their heart rate and pushing the main energy system they’re using from utilizing fat to utilizing sugar. Their body doesn’t have the adaptations to move efficiently at an easy pace. Mark Twight wrote his essay “There Is No Such Thing As A Free Lunch (TINSTAAFL)” based on his experience trying to gain the same endurance training based on high-intensity gym-based training, and how it simply didn’t work. He concludes that it actually set him back. Twight’s accomplishments as an alpinist outstrip his fame as a strength coach, yet he lost hard-earned gains made over years as a world-class outdoor athlete during his nascent development as a strength coach for thinking there was a short cut to endurance training. There isn’t.
Twight, as an alpinist, was and is more than a simple endurance athlete. So are military athletes of all stripes. You have to be capable in many modes. Especially, though, you have to be capable under load. Rucking and running under load are distinguishing attributes that separate median soldiers from elite ones.
The importance of rucking brings up another point: impact on your joints and connective tissues. Too much gym time makes you soft to the impact of running and rucking. We all feel our joints after just two days. In a sentence, you can’t Front Squat your way to a fast ruck time – you have to ruck in order to build speed and toughen your joints to the pounding.
Over the course a long movement, you want it to be easy both aerobically and for your joints. Pain on mile three of a 10-mile movement equals a long day under a ruck. This is why endurance training is so important. It allows you to get to a mission objective without being too smoked to perform at your maximum and then get back out. Other fitness attributes play into that as well, certainly, but under those – strength, stamina particularly – is where endurance moves you from point-to-point
In our first endurance cycle, we focused on building speed under load. The idea was based on dominating a ruck assessment of, say, 3-miles – a common assessment distance for rucking. The idea here is that we want you to move non-stop, even during transitions like today (vest to no vest), for the prescribed amount of time.
Today, at 60 min, I was tired but not crushed at the end. I could have kept going. Nathan covered about 6.5 miles but could probably do 8 in under an hour moving his fastest. He pulled up appropriately on his intensity, but never stopped. At that pace, he’ll be able to do the 90 min. session tomorrow. I covered about 6 miles today. He’s a better endurance athlete than me, so his easy is faster. But we’ll both be able to repeat today’s effort for tomorrow without being wasted. That’s important.
Endurance gains are made over time based on consistent, numbers-based efforts. It’s not romantic or mysterious. It’s not hard to understand. It’s simply effective.
It reminds me of that adage, “It’s easy to be hard. It’s hard to be smart. But it’s usually a good idea.”
Will it work? Can we build a base over 3-4 weeks, maintain some degree of it over the rest of the cycles, then come back and actually make gains rather than retread lost ground? We’re not sure. Certainly, our run times from the interval work in the first endurance cycle has maintained some gains – we’re faster today than before that first endurance cycle. But that’s very different from what the objectives of this cycle are. Most athletes spend months building base, then train heavily in that mode over time. We can’t do that due to maintaining other fitness attributes and the time demands on military athletes – professional responsibilities, etc.
Friel, House, Coggan, and Twight might argue that, no, we can’t see improvements in aerobic base since we don’t train for it long enough. Our sessions are too short and our cycles are too brief. I’d argue we won’t see major, but rather marginal gains, that will be lost and built upon marginally as the cycles ebb in and flow out, but that, ultimately, our easy will become fast. Not as quickly as a pure endurance athlete, but military athletes aren’t pure endurance. Our approach must strike a balance between all of the things you must be capable of doing.