As summer comes to a close, it’s fitting that we conclude the season with a discussion of endurance. We’ve talked about strength (and hypertrophy), speed, power, and agility. The 5th and final capacity of athleticism in our training discussion is endurance. And of course it’s always important to keep in mind that all of these capacities are of equal importance to any lifelong peak performer.
As is our tradition, let’s begin with some definitions. Endurance has both physical and character attributes. It combines cardiorespiratory fitness (the aerobic base and VO2max which enhance the efficiency of oxygen utilization) with muscular fatigue resistance (sustaining submaximal output for extended periods). Endurance also equates with the ability to withstand hardship and be tolerant of stressful situations.
The athlete or fitness enthusiast who possesses endurance has a faster recovery rate compared to those with less of this quality. This is expressed in two manners. Intra-workout, or between bout recovery, is more rapid. It takes you less time to be ready to go again. Inter-workout recovery, or the time (hours, days) required to bounce back after big sessions, is also reduced. There is some metabolic magic going on there.
Endurance is also tied to higher levels of functional independence in later life, reported quality of life, and longevity itself. This probably makes total sense. Do more, be more. Kick ass at life instead of getting your ass kicked. Not just in athletics or fitness, though. Enduring critters participate more in daily life without being sidelined by exhaustion, injury, or illness. That’s fact.
Endurance is probably the most approachable form of training. It’s not overly technical nor does it have extensive equipment requirements. It’s usually not intimidating for most folks. As long as you build up slowly and use good periodization and program design [like our T2 plan], endurance training poses a very low injury risk.
When we train for endurance, our workouts take on a fairly recognizable shape. Steady-state efforts, higher reps, longer intervals, and lengthier workout durations are all characteristics of endurance training. That aforementioned aerobic efficiency results in better fat burning (utilization of fat as a fuel substrate) at lower intensities. This also correlates with a raising of the lactate threshold, or crossover point, in which our bodies shift to more carb-burning and lactate production as demand increases. High endurance means you can go a little harder before you hit that metabolic shift.
Most folks recognize endurance training to be classically represented as steady-state Zone 2 aerobic exercise, or Z2 cardio. While this is the standard means of training, it doesn’t have to be the only way. You can build endurance with interval and circuit training quite effectively and we’ll talk about that as well.
Zone 2 cardio, as in just heading out the door for a walk, jog, ruck, bike, swim – or jumping onto any elliptical, rower, stair climber, etc. – works just fine. But, and this is a major point, finding your personal jam is key. Folks who love and desire that easy, meditative, parasympathetic flow state are naturally drawn to long, slow sessions. Others find that boring as hell and a big turnoff. These folks often do better with a mix of low to moderate intensity intervals and circuit applications to keep things interesting. And of course there’s specificity. It’s great to cross-train using alternative modes, but if you are serious about a sport, most of your endurance training should be in that sport. This is because many of the neuromuscular and tissue adaptations are specific to each sport. For example, if you want to be really good at cycling, you need to spend a significant amount of time on the bike.
At TLA, we utilize the popular 5-zone model to describe aerobic/anaerobic training. Zone 1 is recovery. Zone 2 is endurance. Zone 3 is tempo/threshold. Zone 4 is power/stamina. Zone 5 is redline. There are other terms and I’ve published multiple articles and tables as a resource which can be found in the search box at thelifetimeathlete.com using keywords such as zone training, etc.
You can quantify output in multiple ways. In a very approximate sense, how long you can go at a specific effort will typify the zone you are in. Capable of going for hours? You are in Z1. Sustainable for 1-2 hours, that’s Z2. 10-30 minutes? Z3. 2-5 minutes (the literature suggests 3-8 but I find most lifetime athletes fit better at 2-5) going strong? Z4. Less than a minute and more like under 20 seconds per bout? Z5.
You can slice and dice the zones quite a bit more and be as techy and graphy as you like. Most folks in our community seem to do best with good science kept relatively simple.
I mentioned VO2max, or maximal oxygen uptake, previously. That’s aerobic power, or your top-end output for just a few minutes, like running 1 mile or less. It has a relationship to endurance because the more powerful and efficient your motor is the more work you can do when that motor is just idling along at lower rpm’s. That stated, we do most of our really intense VO2 max interval work during our power-focused training. We still sample Z4 during endurance training, but we emphasize Z2 work. There is beauty in balance. Trying to do everything, all the time, is known where I come from as a shit show.
You can determine that you are in Z2 a number of ways. Heart rate monitoring is very effective. You can hold 70-75% (or so) of max heart rate, or other percentages of VO2max or functional threshold power (FTP). You can take 180 minus your age for a ballpark HR. If you can sustain most of your output using nasal inhalations, this can keep you in Z2 (although I’ve found it holds many trainees at Z1). The talk test is a great one. If you can carry on a conversation using brief sentences, you’re in Z2. Giving a long lecture would be Z1 and the ability to only use short phrases of a couple words suggests Z3.
All of those methods, and others, are totally fine. Going out on a limb here, you’ll simply get to the point where you just can go by feel most of the time. Sure, there can be fatigued states, dehydration, cardiac drift, and other factors which benefit from more exact monitoring, but you can trust your inner instincts here. Endurance training is science, but it’s not rocket science. Hair-splitting and micromanaging is not necessary. If your effort is more than just totally easy, but is very manageable and borderline comfortable, you’ve got Z2 dialed in.
By far the most classic endurance workout is simply a steady, Z2 effort in any continuous movement. Running, biking, swimming, rowing, Nordic skiing, paddling, hiking, etc. These sessions don’t require much in the way of warmup or cooldown. Just start a little easy and cruise along. There are certainly benefits to doing as little as 10-20 minutes of this type of exercise. But 30-60 minutes per session is a real sweet spot. This provides a mix of good training stimulus and easy recoverability. Doesn’t usually require intra workout fueling and fits well into most folks schedules.
Higher levels of endurance can be built by going longer, as much as 2-4 hours depending on the athlete and sport. This type of workout can really test your limits. It will require planning, proper food and hydration, pacing, and some recovery days in the aftermath. That’s because, even though intensity is relatively low, duration is long enough to cause microdamage in tissues and depletion of glycogen stores. Extra long workouts are not really necessary for general fitness, but they are essential for any serious endurance athlete to achieve peak performance in their sport.
A really long (let’s say 2-3 hours) endurance session can also be a grand adventure. Hike, bike, or run to a beautiful destination. Turn it into a social event with a picnic. Or make it a soul-searching vision quest.
You don’t have to peg your HR at the middle or top end of your Z2 range either. It’s OK if you lollygag a little, go easy in Z1, or even take a break or two. This is especially true in any session that feels “longer” for you. It’s also fine if the terrain presents a hill and your effort temporarily touches Z3, or even Z4…however this should be brief in a truly endurance-focused workout.
But if you are someone who doesn’t really dig the steady-state workouts and finds them to feel like mind-numbing, torturous grinds (or any other descriptors you prefer), there are plenty of ways to mix things up and still get a great cardio workout.
We often think of interval training as being solely high intensity interval training. However, in our quest for aerobic fitness and durability, low-to-moderate intensity intervals are excellent. You can take any of those modes of training we’ve been mentioning, like cycling and cross-country skiing, and apply an interval technique to a workout. One way is to hold effort at the upper end of Z2/lower end Z3 for a few minutes and then back off to the Z1-2 border. This works well with longer intervals of 5-10 minutes and shorter (active) rest periods of 1-2 minutes. That’s roughly a 5:1 work to rest ratio and it allows you to dance across the full range of Z2, experiencing a few subtle gear changes in the process.
Interestingly, another way to really spice up an endurance workout is to use some alactic pickups in the session. In this fashion we use a short, submax sprint to “perk” things up, then back off and go easy for a significantly longer period of time to fully recover. If you are running, for example, and you speed up from what you might call marathon or jogging pace to your mile (or slightly faster) pace – but only hold it for 5-10 seconds. That’s a great application of this technique. Then jog slowly for 50 seconds making it a 1:5 or greater work to rest ratio. The alactic (without producing significant amounts of lactic acid) effort is not quite hard enough and certainly not long enough to cause a large metabolic shift into anaerobic glycolysis. I usually don’t suggest folks try to hit Z4 or Z5 because this connotes sustaining the output long enough to drive heart rate up into those zones. We’re not actually doing that here. We’re giving a high, but very brief effort so you “taste” the speed, but avoid most of the fatiguing aspects. While the pacing is different from that zone dance session we just talked about, the heart rate graph will actually look very similar. These types of workouts have been called fresheners, because they break up the monotony and keep things fresh, yet still work primarily in the aerobic energy system. They also help to improve mechanics…a facet often overlooked with endurance slogging. These are not recovery workouts, though, in most cases.
But what if you’d like to experience a workout that doesn’t emphasize steady state cardio, yet still builds aerobic fitness as well as muscular endurance. These can be the type of sessions that work on fatigue resistance and all-day durability throughout the body (and mind). Circuits, ladders, pyramids, clusters, and all sorts of methods can be blended into some great (and fun) conditioning tools and games. As long as the average output intensity sums up in Z2, and we explore changes in density (work to rest intervals), the sky’s the limit. In fact, we have dozens (possibly hundreds at this point) of workouts in our T2 library that do exactly that. You’re only limited by your creativity and imagination.
You can jump to this quick read, Endurance Training Primer, to see an example of this approach. Or just peruse the following video.
In The Lifetime Athlete Training Tribe, our Annual Training Plan features the Endurance Block each fall. We build volume, aerobic fitness, and physical work capacity every September, October, and November. We perform this block in fall because it fits well with autumn weather and many traditional endurance sport seasons. Some of this training progressively increases distance and duration in the modes of choice of the team members. Other aspects of the conditioning system use our capacities of strength, speed, power, and agility…to positively affect endurance. Get results. Have fun. Don’t get hurt. That’s our focus.
Endurance is more than just Zone 2 cardio. It’s tied into that will to win, refuse to lose, never say die attitude. Endurance is a quality that every Lifetime Athlete needs…and deserves.