If You Love Your Sport, Stop Ignoring These Training Red Flags

The “pain cave” is real, and if you’ve followed elite endurance athletes lately, you’ve seen what it looks like when someone can choose to go there on purpose and stay there longer than almost anyone else. The New York Times recently highlighted Jessie Diggins’s ability to enter that place in big races—driving herself to the edge of what her body can handle and holding it there until the line. Ultrarunner Courtney Dauwalter describes her own pain cave as a dark room in her mind where, when it feels like she can’t take another step, she grabs a “chisel” and goes to work making that space bigger, one hard mile at a time. Eliud Kipchoge talks about something similar from the roadside of endurance, saying long runs make his mind strong and teach him to “respect that pain,” because marathons are won in the uncomfortable work that comes long before race day.

That ability to suffer on demand is part of what makes these athletes special. But there’s an important distinction between that and the red flags I’m going to talk about in this article—and if you love your sport, you need to get really clear on the difference. The pain cave is what you enter when you’re pushing your limits on purpose, inside a structure that’s been built for that effort: months of preparation, a defined finish line, a recovery plan on the other side. Red flags are different. They’re your body and brain telling you that the baseline is off—fatigue that doesn’t clear, performance sliding over weeks, the same niggles coming back, mood and sleep going sideways, recovery trending the wrong way.

You could sum it up like this:

• The pain cave is acute, time‑limited, and part of a planned peak or test. You go in, suffer, come out, and then you recover.

• Red flags are chronic, background signals that something isn’t recovering even when you’re not racing, testing, or going all‑out.

Since we’re around Valentine’s, it’s worth saying this out loud: gaslighting and self‑abuse are not love—whether we’re talking about relationships or the way you treat yourself in training. Loving your sport sometimes means doing hard, uncomfortable things on purpose; gaslighting yourself in the name of your sport means ignoring every warning sign your body gives you and calling it ‘grit’ until something breaks. The whole point of this piece is to help you spot the difference.

What makes athletes like Diggins, Dauwalter, or Kipchoge successful over the long term isn’t just that they can tolerate pain; it’s that, at their best, they and their teams know when that suffering is productive and when it’s crossing a line. Even they have had to learn boundaries—how to distinguish “this hurts because I’m pushing my limits today” from “this hurts because my system is overloaded and something’s about to give.”

I’m not here to tell you to avoid discomfort. I’m here to help you tell the difference between the kind of hard that makes you better and the kind of hard that slowly takes the sport you love away from you.

When the Strong Engine Starts Misfiring

In that “strong engine, weak chassis” analogy from the previous article, most athletes obsess over horsepower: paces, loads on the bar, intervals, hard sessions. Very few pay the same attention to reliability—how well their body actually tolerates and recovers from all that work over weeks and months. That’s where things go wrong.

Most injuries and burnouts don’t come out of nowhere. The body almost always whispers first. It’s just that many athletes are really good at ignoring those whispers because they’re chasing the next performance high or scared of “losing fitness” if they back off for a few days.

Think of the rest of this article as a quick guide to what those whispers sound like—across endurance, strength, and team sports—so you can catch problems early and keep enjoying your sport instead of spending another season watching from the sidelines.

Red Flag 1: Fatigue That Doesn’t Add Up

Everyone gets tired; that’s part of training. But not all fatigue is created equal.

There’s the normal “good tired” you feel after a hard block, where a few easy days and some sleep bring you back to feeling sharp. Then there’s the fatigue that hangs around, starts leaking into everything, and doesn’t really match what you’re doing on paper.

Some examples:

• Workouts that used to feel comfortably hard suddenly feel like a fight, even though the plan hasn’t changed much.

• Easy days don’t feel easy anymore; you’re breathing harder, your legs feel heavy, and you don’t really “switch off” during the session.

• You wake up tired several days in a row, even when your sleep is technically fine.​

This isn’t about one bad day. It’s when 3–5 sessions in a row feel heavier than they should, and you need more caffeine, more hype, and more self‑talk just to get through normal training.

If that’s you, don’t badge it as toughness. See it for what it is: a sign that your body is paying interest on your recent training debt and you haven’t given it enough time to clear the balance.

Red Flag 2: Performance Quietly Sliding

Another subtle warning sign: you’re not just plateauing—you’re slowly getting worse.

This can look different depending on your sport:

• Runners, cyclists, or team athletes: your usual paces feel harder, or your heart rate is higher than normal for the same work.

• Lifters: weights that used to move fast now grind up, or you’re losing a rep or two at loads that used to be automatic.

• Field sport athletes: your accelerations and jumps feel dull; you’ve lost a bit of “snap” even on good days.

Short‑term dips can be part of a smart plan. Sometimes you intentionally push into a heavy block and expect to feel a bit slower before a deload. The red flag is when there is no planned deload, yet over 1–2 weeks, you see a clear downward trend in performance, not just random day‑to‑day noise.

Your engine might still feel strong in your head, but your dashboard (times, reps, bar speed, jumps) is blinking at you. When that happens, the answer is rarely “do more.” It’s almost always “do a little less, a little smarter, right now.”

Red Flag 3: The Same Niggles Keep Coming Back

Very few serious injuries are truly random. Most of them were preceded by a bunch of little episodes that were easy to shrug off.​

Pay attention to:

• The same calf, hamstring, groin, shoulder, or low back feels “a bit tight” or sore after certain sessions.

• A niggle disappears when you rest, but returns like clockwork when you ramp up intensity or volume again.

• You notice you’re subtly changing your technique to avoid discomfort—shortening your stride, shifting weight on a lift, avoiding certain cuts or jumps.

Those “hot spots” are tissues that are telling you, “We’re not keeping up.” Ignoring them and hoping they go away as you add more load is like ignoring a rattle in your car and then being surprised when something finally breaks.

It doesn’t mean to stop everything at the first whisper. But you do need to modify the stress on that area: adjust volume or intensity, change the exercise selection, add some targeted strength or isometric work, or target the rest and recovery. Doing nothing and pretending it’s fine is a choice—but so is playing the long game.

Red Flag 4: When the Joy Starts to Slip

Overreaching and overload don’t just hit your muscles; they hit your nervous system and your mood.

Early signs often show up as:

• Feeling unusually flat or indifferent toward sessions you’d normally look forward to.

• Getting irritable or snappy around training or competition time.

• Feeling “wired but tired”—you’re restless, struggle to switch off, but also feel drained.

For people who truly love their sport, losing that sense of excitement is a big deal. When you start dreading the session, not because it’s hard, but because you feel like you’ve got nothing to give emotionally, that’s a flag.

It doesn’t mean you’ve fallen out of love with the sport. It usually means the total load—training plus life—is more than your system is currently coping with. Instead of questioning your passion or character, question the inputs: the schedule, the sleep, the intensity, the other stressors, and the lack of lighter days.

Red Flag 5: Recovery Data Trending the Wrong Way

You don’t need to be a data geek, but if you already use basic metrics, you might as well listen to them.

Useful things to keep an eye on:

• Resting heart rate slowly creeping up over several days.​

• Sleep quality worsening: more awakenings, a harder time falling asleep, feeling less refreshed.​

• Simple field tests (a few jumps, a short sprint, even a grip‑strength squeeze) consistently down across multiple sessions.

Any single day can be an outlier. What matters is trend plus context: if all the arrows—fatigue, mood, minor pain, and your simple metrics—are drifting in the wrong direction while your training is ramping up, you’re not being “hardcore” by ignoring it. You’re just gambling with your availability.

The win here is not obsessing over every number; it’s using patterns to nudge you toward better decisions.

What To Do When You Spot a Red Flag

Noticing a red flag isn’t a reason to panic or tear up your whole plan. It’s a prompt to course‑correct before the price gets higher.

Here’s a simple way to respond:

• Pause and review the last 10–14 days. Look at overall load: how many hard sessions, how many high‑impact efforts, how well you actually slept, and what life stress was layered on top. Often, you’ll see exactly where things spiked.

• Dial back, don’t slam on the brakes. For most athletes, a smart first step is reducing volume or intensity by 20–40% for 5–7 days rather than stopping completely. Keep a little quality in there so you still feel athletic, just with less total stress.

• Support your weak links. If the same areas keep grumbling, make them a priority: add two short sessions a week of targeted strength or control work, not just stretching or foam rolling. Think, “What needs to be stronger or more robust for my sport’s demands?”

• Adjust the plan, not your standards. You’re not lowering your expectations by backing off; you’re protecting your ability to hit those expectations over months and years. The best athletes are ruthless about adjusting inputs to protect long‑term output.

• Get outside eyes when needed. A good coach or clinician can often spot patterns and blind spots you can’t see from inside your own head. If the same issues keep returning, get help sooner rather than later.

Loving your sport isn’t about proving how much you can suffer; it’s about making choices that let you keep showing up, year after year. The athletes who last aren’t the ones who never see red flags, but the ones who notice them early and adjust before they become breaking points. That adjustment doesn’t mean doing less of your sport or living in the gym—it means treating strength and conditioning as non‑negotiable maintenance for your chassis, the same way you’d maintain any important relationship. With a bit of intention, you can build and protect a stronger body with short, focused work—even at home—so that every hour you spend in your sport has a solid structure underneath it. If your goal is a long, healthy relationship with your sport, listening to those warnings and doing the work to stay strong isn’t weakness—it’s respect, both for your body and for the game.