Effort and Output
Three Things #189: October 5, 2025
It’s that time of year again: marathon training is in full swing. It’s been two years since my last marathon, and I’m two years older. Being older and not having run very much for a couple of years has made this season’s marathon training that much harder.
As a result, for the first time ever, I’ve begun to pay attention to heart rate while running. I’ve noticed that it’s higher than I expected, and higher than I’m used to. Whereas I used to only look at speed and distance, I’m mostly running indoors these days, and there’s a lot less to look at, which is maybe why I’m paying more attention to my vitals. And I understand heart rate zones and pace zones a bit better than I used to.
For instance, I now know that you want to spend most of your training in Zone 2, which is an easy, conversational pace. The advice I’ve read suggests at least 80%, and that you also want to add a little bit of Zone 5 (max effort) work each week, e.g., one set of intervals. I’ve also noticed that even when running feels easy, my heart is in fact working harder than I expected, in Zone 3 or sometimes even 4. This is a bit dangerous. If you spend too much time in the higher heart rate zones, you’re doing a lot of work but you won’t have much to show for it. Zone 2 is the sweet spot for endurance training; more than this and you’re just putting unnecessary stress on your heart.
The more training I do, and the more I think about heart rate zones, the more I see parallels to the way I do other kinds of work.
Thing #1: Know Your Zones ⏱
The first thing to understand is that effort is like a muscle. The analogy may feel strained, but in my experience it’s surprisingly apt. When you’re not used to work, even a little bit of work feels stressful. When you’re “in the zone”, you can work for hours and not even notice it, feeling like a machine. This is precisely like running.
You notice this effect after a holiday, or after you’re sick. That first day back at work is brutal. You open your laptop and stare at the screen blankly, unclear what to do first, and a bit intimidated by the task. You need to warm up those “work muscles” again and get back in the zone. Usually within a few hours, or a day or two max, you’re fully warmed up and work feels normal again.
It’s the same with running. When I run every day, getting back into the groove each time is effortless. I’m confident and feel hungry before I start a run. The running itself feels effortless, easy, and light. I’ll run without thinking about it even if I’m short on sleep, jet lagged, or even feeling a little under the weather. The entire experience feels joyful, and I always feel better after a run regardless of the condition I was in when I started.
But when I haven’t been running for a while, it’s anything but joyful. The very thought of running gives me anxiety. Will I be okay? How much slower will I be? Might I injure myself? Did I get enough sleep? Etc.
Work is the same. The more you work the work muscle, the easier work becomes. The longer it’s been, the more “sore” you’ll feel, and the slower it is to get back into it. This is why it’s so important to keep up a healthy work routine whenever possible.
The second thing to understand is that effort is not the same thing as output. Any athlete will tell you that it’s possible to train hard and it’s possible to train effectively, and these two aren’t the same thing. Take heart rate and pace zones. The most effective training, at least for distance running, is running that feels easy—too easy, in fact. Pushing harder is, ironically, worse for you, unless done in a very strategic manner (more on this in a moment).
It’s not always easy to precisely measure the output of our work, and in my experience most quantitative metrics fall short: for instance, developers should never be measured on lines of code output. But you know it when you see it, or when you feel it. You know when you’re working effectively, and you know when you’re not. The best example of working effectively is the feeling of being in a flow state, where the work feels effortless and you just know that you’re doing competent work. And the best example of the opposite is busy work, especially when you’re tired, unfocused, or unwell: staring at the screen, unable to process the information in front of you. We’ve all experienced the latter, and I think most of us have experienced the former.
I don’t love the term “work smart, not hard” because it’s not about “smarts” or intelligence, per se, but it is about understanding your own work style and rhythms and controlling for them. It’s about understanding what time of day, what time of the week or month, etc., you can be most effective. It’s about understanding what type of work energizes you, and what type drains your battery, and spending as much time as possible on the former and as little as possible on the latter. It’s about understanding how to structure your day, and your life, around productive work sprints. It’s about making sure you have adequate rest time, that the other things in your life are in order, that you’re healthy overall, and that you have the opportunity to step back, clear your mind, and consider the big picture.
Naval Ravikant put it best when he said that we want to work like a lion: do a few short sprints where we’re exceptionally focused, able, effective, and inspired, and spend the rest of the time, most of the time, working at a lower intensity. In other words, rather than spending most of our time running in Zones 3 and 4, which I think is what most people do, and which is unfortunately ineffective as discussed above, we should spend 80% of our working hours in Zone 2, and “sprint” in Zone 5 when and where possible, in a smart way.
Thing #2: Jog 🏃
Let’s start with the Zone 2 work. The pace of this work should feel unchallenging and sustainable, like an easy run. Working at this pace, you should be able to go all day without feeling overly burdened or stressed. The canonical activity in this zone is catching up on email or Slack messages. It’s hard to specify the content of this work, because it will vary from person to person based on discipline, role, preference, and personality. For me, in addition to catching up on comms, this would include taking meetings, reading articles and papers, thinking time, travel, attending events, and speaking engagements.
You’re spending around 80% of your time in this zone, so this is where the majority of your input goes, but it’s not where the majority of your output comes from. To be clear, even in Zone 2 you should be making an effort to work productively and not waste your time, but productivity shouldn’t be your focus. Instead, your focus should be on structured inputs. Create a task list, order it, choose 1-3 main tasks each day, and execute them in sequence. Zone 2 is all about plodding, productive, linear work.
It’s also worth considering how to plan your work week. Here I’ll turn back to my workout schedule: I work out six days a week, and take one day off a week to rest and recover. I generally start the week with a hard workout, since that’s when I’m fully rested, then have an easy day or two, then another hard day, then another easy day or two. The point is to spread out the hard work and give yourself a chance to actively recover in between hard workouts. Think peaks and troughs, or hill climbing, with one or two smaller hills and one big summit each week.
Of course it’s not possible to perfectly predict when you can sprint. It largely comes down to when you feel inspired. But as I’ve paid attention to my energy level throughout the day and throughout the week, I’ve actually become pretty good at predicting when I can sprint, and I encourage you to try doing the same. For instance, I’m an early bird so I know that I’ll always be higher energy in the first part of the day, before lunch. I try to structure my day so that I do the hardest, most important thing first, and then take on easier, less stressful work in the second half of the day.
You probably also have a peak of energy and inspiration at some point during the day or week. For most people, this isn’t Monday, when you’re still recovering from the weekend and working off social jet lag, and it isn’t at the end of the week either. So it might make sense to schedule your sprint time mid-week.
For some people, it will make sense to take an hour or two each day for sprinting, and spend the rest of each day in Zone 2. For others, it will make sense to take a sprint day each week, or even a sprint week each month—I’ve written about this sort of personalized pacing before, and have found it to be terrifically productive in my daily life.
The key idea is to spend the majority of your time in a sustainable pace zone so that you’re well rested and in good form when it comes time to sprint.
Thing #3: Sprint ᯓ🏃🏻♀️➡️
Zone 5 is where the magic happens. If Zone 2 is all about doing the essential tasks and “building a base” of work capacity (as we say in running), Zone 5 is where the real progress is made. Running a lot in Zone 2 will turn you into a capable but slow distance runner: able to run very far, at a slow pace. Adding some Zone 5 work is what will turn you into a speed demon—or, in the context of work, it will allow to work deeply with great inspiration and accomplish things you didn’t think were possible.
As with running, the key ingredients for effective Zone 5 work are preparation and focus. The day before a Zone 5 workout you need to make sure you eat well and rest well. You need to get enough sleep (if I don’t sleep well the night before, I postpone sprinting for an easier workout). You need to carefully plan when and where you work out. Timing is important because ideally you want to work out at the time of day when you’re relatively high energy. And place matters because when you’re sprinting as fast as you can, you don’t want to be dodging potholes or other runners (hint: use a running track). In other words, you want to set yourself up for success.
For me, the most important ingredient for a Zone 5 work day is time. I need long, uninterrupted spans of time. Some people prefer to “sprint” for only about an hour, but I find that my effective minimum is about three hours. Any less than this and I begin to feel anxious about what comes next, whether a meeting, a workout or anything else. There’s something about three hours that allows me to totally switch off the anxious part of my brain, because it just feels like “enough” time.
You also want to minimize distractions. Turn off all notifications on all of your devices. Close all of your chat apps. Zone 5 work time is NOT the time you want to be checking email or Slack messages, or scrolling social media. These things are all strictly forbidden while sprinting. Many people find it helpful to have a ritual involving the five senses to get into the zone: a particular visual scene, a particular beverage, a particular type of outfit, a particular type of music (or silence), etc.
There are different kinds of zone 5 work. One kind is building, focused on a deliverable. If you’re a writer, a coder, or a designer, this is when you can really get into the zone and get the bulk of your work done. In my experience, my productivity is at least 3x and possibly as much as 10x when I’m in focused, sprint mode, relative to Zone 2. I can spend all day trying to deliver an article or a project, noodling here and there, constantly fighting distraction and context switches. Or, I can knock out the entire thing in an hour or two during a sprint, and then switch to Zone 2 work for the rest of the day.
But there’s another Zone 5 mode which is more about ideation and creativity. This is where the running metaphor breaks a little bit, because it’s not about sweating or getting your heart rate up. It’s basically the opposite. For me, this means leaning back in a comfortable chair, with a coffee or tea at hand, and several hours of reading material: an academic paper, a white paper, or a technical book. This is where the important synthesis work happens: integrating the things I’ve been working on with reports of others’ work, with deeper ideas from books or, sometimes, podcasts. This could also be done during a walk outside—walks are known to be especially useful for ideation and creativity.
It’s impossible to be in Zone 5 work all the time because it’s draining and because we just can’t carve out that much time each week to shut out the world and completely focus. However, it’s absolutely essential, regardless of the nature of your work, that you find at least some Zone 5 time each week. The key idea here is to take the time to understand your work, your energy level, and how you structure your week, to carve out some time for deeper, more intense, more effective work. Try it, you’ll be amazed at the results.