Pace and Difficulty

Training is not just about how far or how fast you go. . .

. . . it’s about understanding what “pace” and “difficulty” mean, and how they show up differently in your body, your effort, and your recovery.

Two athletes can move the same pace and have completely different experiences. One can walk away refreshed. The other can limp home wrecked.

The difference? Not just fitness. It’s how pace and difficulty interact.

Defining these terms with precision is an important part of understanding how your training plan reflects your bigger goals. Below, we’ll focus on differentiating Exercise Intensity (EI) from difficulty (D), and show you how we can interpret this information and then leverage it for maximum gains in your training. Whether you’re a seasoned runner or adventurer, or just returning to structured workouts, this clarity is essential. We build from here.

Defining “Faster” in Training

The definition of “faster” seems self-evident. But when we talk about getting faster in training, it’s important to clarify what that really means. There are two key definitions of “faster,” and both matter for athletes and adventurers of all levels:

·         Higher Speed for the Same Effort: You can cover more distance or go at a higher pace without working any harder than before. In other words, your cruising speed improves.

·         Same Speed for Less Effort: You can maintain a given pace, but it feels easier than it did before. This means your efficiency has improved. For example, running at a 10 min/mile now requires less energy or exertion than it did previously.

At first glance, the first definition (higher speed at same effort) sounds like the obvious goal of training. However, the second definition (same speed with less effort) is actually the foundation for most training progress. When you can hold your usual pace but with less exertion, you’ve unlocked the ability to either go longer at that pace or take less rest while moving at that pace. These two forms of improvement are the true foundation of sustainable training (and athletic growth).

Progression Through Extension and Compression

In training wisdom, progress is usually achieved via extension or compression of workouts. Both of these rely on improving your efficiency (definition #2 above: same speed, less effort) which enables you to handle more work over time:

·         Extension is gradually increasing how long or how far you can maintain a given effort or pace. For example, if you initially do a workout of 5× (10 min on, 5 min easy) – that means 5 sets of 10 minutes at work pace with 5-minute easy recoveries in between each 10 min chunk, totaling 50 minutes of work – an extension progression might be doing 6×(10,5) or 5×(12,5) the next time. This adds more total work duration (e.g. 60 minutes of work instead of 50) at the same pace.

·         Compression is gradually reducing the rest or recovery taken while moving at a given pace, and by doing so, packing the same total work into less time. Using the same 5×(10,5) workout example, a compression progression could be 5×(10,4) or 5×(10,3) . . . still 5 sets of 10-minute work bouts, but with only 4-minute or 3-minute easy segments between. You’re doing the same 50 minutes of work, but with shorter rests, which makes it more challenging.

In practice, a training plan will have you repeat a certain workout or pace, and a week or two later progress it by either extending the reps/duration/distance or compressing the rest. Over weeks and months, these small steps build your capacity. The iterations are almost endless. You can keep stretching out how long you hold a pace, or keep trimming down the recovery, as your fitness improves. The main idea is progression by extending or compressing the work over time.

Intensity vs. Difficulty: Not the Same Thing

One common source of confusion for athletes is the difference between Exercise Intensity (EI) and workout Difficulty (D). In exercise science, Exercise Intensity (EI) refers to how hard you’re working in objective terms. It’s often tied to metrics like pace. A very fast run (relative to your ability) is high intensity, and a slower jog is lower intensity. However, intensity is not the same as difficulty. A workout’s Difficulty is about how challenging it feels overall, which depends on more than just how fast you go. Difficulty includes factors like how long you maintain that effort and how much rest you get. In other words, difficulty is the subjective strain of the session (how hard it feels), whereas exericise intensity (EI, or just “intensity”) is the objective level of effort or speed.

To illustrate this difference, every workout in the Heretic Trail program is labeled with both an EI (to denote the intensity domain or effort level) and a Difficulty rating (how hard the session should feel on a 1–5 scale). Let’s look at two scenarios that show how a workout can be high-intensity but not very difficult, or low-intensity but very difficult:

·         Scenario 1: High Intensity, Moderate Difficulty. Imagine you hop on a treadmill and run or hike at a pace you could hold for 20 minutes in an all-out time trial (TT). That’s a pretty fast pace – clearly a high-intensity effort for you (near your max sustainable speed for that duration). Now suppose your workout is prescribed as 10×(1 min on, 1 min walk/jog off) at that 20-minute TT pace. In total, you’d be doing 10 minutes at this fast pace (broken into 1-minute bursts) with ample one-minute recoveries in between. Assuming you’re well-rested and conditioned, this session won’t feel too taxing. It’s more of a maintenance or speed-touch workout – you get to practice moving quick, but the short reps and equal rest mean you never accumulate much fatigue. You’d likely finish feeling energized, not exhausted. On a difficulty scale of 1 to 5, this might rate around a 3 – a solid day, but nothing that pushes your limits. In this case, the intensity of each fast rep is high (it’s your 20-minute race pace), but the overall difficulty of the workout is moderate because the volume is low (only 10 minutes total at that pace) and recovery is generous.

·         Scenario 2: Lower Intensity, High Difficulty. Now imagine a different day on the treadmill at a much slower speed – a pace you estimate you could hold for 2 hours in an all-out effort. This is a lower-intensity pace (clearly much easier per minute than your 20-minute TT pace). But the workout prescription is 4×(30 min on, 5 min walk/jog off). That means 4 repeats of 30 minutes at this “2-hour” pace, with only a short 5-minute easy break between each. Even though each minute isn’t fast, you’re stringing together a lot of minutes at that pace – two full hours of hard movement in total, broken into four large chunks. Given the sheer volume, this becomes a very difficult workout. By the last rep, you’d be digging deep: muscles aching, fuel running low, mind fighting fatigue. We’d peg the difficulty at least a 4 out of 5. It’s the kind of session that would only appear after months of buildup, and it would likely require a few days of recovery afterward. In summary, the intensity (EI) here is relatively low, but the overall difficulty is high because of the long duration and minimal rest. In sports science terms, you’ve accumulated a huge training load from this workout.

These two scenarios highlight why every planned workout has both an Exercise Intensity target and a Difficulty rating. You can’t judge a session’s challenge level by pace alone; how the workout is structured matters immensely. Both types of training have their place, but they must be understood and executed in context.

Adjusting Workouts (Preserve D and EI!)

One of the key skills in effective training is learning to adjust on the fly to meet the intended Exercise Intensity and Difficulty. Here are two important guidelines we give athletes regarding EI and difficulty – one before/during the workout and one after the workout:

1.      Before/During the Workout – Match both the intended Difficulty and EI, but modify intensity (by modifying volume) if needed. That is, always aim to complete the workout at the prescribed levels for both D and EI, but if it’s necessary to modify in order to finish, reduce the reps/distance/duration (EI) and not the difficulty.

Example: Your session for the day is planned as a moderate (say Difficulty 3 out of 5), so it should not turn into a gut-busting grind. But once in a while, despite the plan, you might find that a workout is feeling harder than it’s supposed to. Maybe you’re unusually fatigued, or the weather is brutal, or you’re just having an off day.

If the workout is feeling harder than prescribed, do not slow down the target pace (EI) but do cut it short.

This means you might drop one or more repetitions, or reduce the distance or duration of a segment. But you keep the planned pace. Preserving the pace is critical.

The single biggest mistake athletes tend to make when struggling is that they often slow down to complete the full volume of the workout (because they’re fixated on hitting a certain mileage or time). In our approach, the pace and effort are the more important variables to meet . . . it’s better to do a bit less intensity volume than prescribed than to alter the intensity. For example, if you were supposed to do 5 repeats but you’re faltering, it’s preferable to stop at 4 solid repeats at the right pace rather than slog through a fifth at a slower pace. You’ll still reap the intended training stimulus, without overstressing your body by reaching into the reserves you might not have. Keep in mind: the goal of training is to teach your body the right signals, not to check every box no matter what.

2.      After the Workout – Communicate the reality of what happened, and Learn: if you did have to adjust a workout (or if it just felt much harder than it should have), let your coach know or make a note of it in your training feedback. This feedback is critical. A workout coming out too difficult isn’t a failure or a test you “failed” – it’s data.

There are many reasons this can happen. Perhaps life outside training has been stressful or you slept badly, leaving you with accumulated fatigue. Perhaps you’re coming down with a bug, or still carrying soreness from prior sessions. Or it could be that the workout was a bit too ambitious in its design – training is an ongoing feedback loop, and sometimes the best plans still overestimate (or underestimate!) what you can handle on a given day.

Try to take a neutral view of adjusting a workout. It’s nothing more than your body responding appropriately to all the stressors in your life (physical, mental, etc.) that can intersect in any given moment. Use that information. With your coach (or on your own if self-coached), figure out how to adjust going forward. Maybe you need an extra recovery day, or to tweak the upcoming training paces, or simply chalk it up to a bad day and move on. Training improvements rarely follow a perfectly linear path – and that’s not only okay, it’s actually to be expected. What matters is that you listen to your body and adjust the plan intelligently.

Often, the best move after an unexpectedly tough day is to take a couple of easy days or rest, absorb the training you did accomplish, and then continue with the progression once recovered. There are always options, but they all start with honest feedback about how the workout felt.

By adhering to these two principles (preserve the intended D and EI, and communicate the reality and learn), you ensure that you’re training the right qualities and staying on track. Over time, this approach prevents small hiccups from derailing you. Every workout remains a productive one, and modifications are successes, not demerits.

The 1–5 Difficulty Scale: Why Easier Is Often Better

Let’s talk more about the Difficulty ratings (1 through 5) and how they’re used in practice.

At Heretic Trail, we rarely assign workouts at a Difficulty 4, and Difficulty 5 is reserved solely for races, peak events, or special Diagnostic TT efforts where you’re giving what you’ve got for that day. The vast majority of day-to-day workouts should feel like a 1, 2, or 3 on that scale. Difficulty 4 (very hard sessions) are sprinkled in sparingly, only when needed and only with plenty of rest before and after. This approach might sound counter-intuitive, especially in a fitness culture that often glorifies “crushing it” every time you work out. You’ve probably heard sayings like “go hard or go home” or “do your easy runs easy and your hard runs hard.” The truth is, if you want consistent progress, most workouts should not be truly “hard.”

Why so much focus on keeping training difficulty under control? Because no single workout will make or break your fitness. What really makes you better is the cumulative effect of consistent training over weeks and months. You’re far more likely to improve by stringing together many moderate, sustainable sessions than by throwing down a heroic effort that leaves you wrecked for days. In fact, sports science research backs this up: significant gains come from regular training stimuli that build up over time, not from one-off maximal efforts. Your body adapts gradually, and it needs consistent signals – not constant exhaustion – to get fitter.

Moreover, if you push too hard too often, you risk overtraining and injury, and you compromise the consistency that true progress requires. A workout marked Difficulty 4 is by definition very demanding; doing one will likely require extra recovery. That’s why in our training plans a level-4 workout might appear only once every few weeks. In between, the focus is on low to moderate difficulty workouts that you can absorb and bounce back from quickly. The exact timing depends on the individual and their progression of training, but the principle is universal: you can’t be red-lining every day or even every week and expect to keep improving without something breaking down.

Finally, it’s worth reiterating: it’s almost universal that athletes are more likely to do a workout too hard than too easy. It’s human nature, fueled by competitive spirit and the pervasive “no pain, no gain” mentality we live in. But remember, training is not an exam, and slogging yourself into the ground is not a badge of honor. “No pain, no gain” is a dangerous myth in smart training environments. Gains come from the right amount of challenge, followed by recovery, and repeated consistently. If you finish a workout thinking, “Hmm, I could have done a bit more,” that’s actually perfect – it means you nailed the intended difficulty and will be able to train again in a day or two feeling stronger. Contrast that with finishing a workout utterly destroyed (a true Difficulty 5 effort) – you might need nearly a week to feel normal again, during which time you’re not doing much productive training. As a coach, I’d much rather you err on the side of slightly too easy than too hard. Over time, those “slightly too easy” days stack up into major fitness gains.

In Summary – Keep It Manageable, Keep It Consistent

For athletes of all experience levels and ages, these principles hold true. If you’re newer to training, this approach will significantly decrease the chance of you burning out or get getting discouraged. You’ll see steady progress without feeling like every session is a killer. If you’re experienced or even elite, understanding the nuance of pace vs. effort will help you train smarter and continue improving. The technical details of pace, intensity, and training structure are there to guide you, but the big picture is simple: consistent, progressive training – done at the right difficulty – beats intermittent all-out efforts every time.

So embrace the easy and moderate days, trust the process of extension and compression, and communicate with your coach and/or log when things feel off. In the long term, your body will reward you with better performance, and you’ll enjoy the journey more. Remember, the goal is to finish most workouts feeling energized, not annihilated. That way, you can show up again tomorrow and keep building on what you did today.

This is the secret to getting “faster” in a sustainable, effective way.