After fifteen-plus years in the fitness industry, there’s one pattern I see more than almost any other, and it’s not the client who’s obviously under-eating. Those ones are easy to spot and easy to fix. It’s the client who’s only a few hundred calories short each day, week after week, with no visible weight loss to show for it.

If you’re reading this and thinking “that sounds like me”, training consistently, not seeing the results you think you should, feeling flat, picking up niggle after niggle, you’re exactly who this post is for.

I see this show up constantly with clients chasing running goals: hitting the gym three to five times a week, genuinely trying to watch what they eat, leaning toward “low-calorie” options because that feels like the sensible move, and yet the weight won’t budge. It feels counterintuitive, but that mindset is often exactly what puts someone into this trap. It’s not a big enough shortfall to actually lose weight, but it’s just enough of a reduction to make things harder down the track. In my experience, it’s far easier to lose weight starting from a healthy, higher calorie base than it is from a base that’s already been quietly trimmed down for months. If your body’s used to running on less, there’s less room to create the kind of deficit that gets results, you’ve made your own job harder without realising it.

It turns out there’s a real name for what’s going on: Low Energy Availability, or LEA. And while most of the research is done on competitive athletes, I see this exact pattern play out every week in everyday people, busy parents, weekend warriors, people just trying to get fitter and fit training around a full life.

What the research says, and what I see in the gym

LEA happens when someone isn’t eating enough to cover both normal body function and the energy cost of their training. A 2025 review pulling together data from hundreds of athletes found that well over half were at risk of this kind of energy deficiency, and that those affected showed measurable drops in performance, endurance, coordination, concentration and decision-making, plus more time missed to illness.

You don’t need to be a competitive athlete for that to land close to home. Swap “competitive athlete” for “parent trying to fit in three sessions a week” and I’ve seen the exact same thing walk into my gym more times than I can count: someone who’s training hard and eating what they think is “healthy,” but who’s flat by 2pm, can’t concentrate at work, and can’t understand why their running isn’t improving.

The damage starts before you’d ever notice it

Here’s the part that really matters, and it’s backed by more recent research: several studies on short-term, moderate energy shortfalls found stress hormones rising, muscle recovery processes slowing down, and direct drops in strength and endurance performance, all showing up before there was any visible change in body composition. The damage doesn’t wait until the deficit is big enough to see on the scales.

This is precisely the scenario I run into again and again with new clients. They’re not “under-eating” in any dramatic sense. They just haven’t quite adjusted their food to match a jump in training. A few hundred calories short, day after day, and by the time I meet them, they’re carrying a nagging injury, they’re exhausted, and they’ve completely lost momentum with their training. Not because they trained wrong. Because they didn’t fuel what they were asking their body to do.

Why the scales don’t tell you the truth

One of the most consistent findings in this research is that the body doesn’t just sit there and burn fat indefinitely when it’s underfed, it adapts. Metabolism slows, hormones shift, and the body works hard to protect its current weight. Athletes who look completely weight-stable have still been shown to have impaired hormonal function underneath, purely because the deficit is being masked by these adaptations rather than resolved.

I’d say this is the single biggest misunderstanding I deal with in everyday clients. People assume that if their weight isn’t dropping, their eating must be “fine.” In reality, some of the most run-down, injury-prone, unmotivated clients I’ve worked with have looked completely normal on the scales the whole time. That’s the trap, no dramatic weight loss, no obvious red flag, just energy and progress eroding in the background while everything looks fine on the surface.

The pattern I see walk through the door

Bring this research down out of the lab and it maps directly onto the exact clients I see struggling to be consistent:

• Persistent low energy, even with what should be enough sleep, this is the parent who’s dragging by mid-afternoon no matter how “clean” they’ve been eating
• Training sessions that feel harder than they should, this is the weekend warrior who used to bounce back easily and now dreads their long run
• Niggles, tightness or overuse injuries that keep recurring, this is the client who’s had the same calf or hip issue flare up three times this year
• Performance plateauing or going backwards despite consistent effort, this is the person doing everything “right” and still not improving
• Motivation and mood dipping for no obvious reason, this is the client who used to love training and now has to force themselves to show up

Individually, any one of these could be a bad week. Together, over months, with no change on the scales, that’s the LEA pattern, and it’s the number one thing that stops people from training consistently. Not lack of discipline. Lack of fuel.

Why I don’t chase daily numbers with my clients

Given all of that, one of the most useful things I do with a new client isn’t hand them a strict daily meal plan. It’s take an honest snapshot of what they’re already eating, energy in versus energy going out, and use that as the real starting point, not a textbook formula.

From there, we build back up gradually. Because the same research on metabolic adaptation applies in reverse: if someone’s body has adjusted to running on less fuel for a long time, tipping in a big surplus straight away doesn’t fix the problem, it just risks rapid, unwanted weight gain. So we increase calories, and particularly protein, in small, progressive steps, giving the body a genuine chance to adapt rather than shocking it in either direction, the same principle that shows up again and again in this research on how the body responds to energy availability.

Just as importantly, I get clients looking at their intake across the whole week rather than obsessing over a single day. This is the difference between something a busy parent can actually stick to and something they abandon after four days. Trying to hit a perfect number every single day is exhausting and, in my experience, it’s exactly why so many people give up on nutrition altogether. Looking at the week as a whole takes the pressure off and gets the same result, because performance and recovery are built over days and weeks, not any one meal.

Recovery starts with fuel, not just rest

It’s easy to get excited about a training plan, the sessions, the structure, the progression. But if you can’t recover from that training properly, the plan doesn’t matter much. And recovery isn’t just sleep and easy days; the research is clear that it starts with whether your body has enough fuel coming in to actually repair and adapt from what you’re asking it to do.

This is exactly why, after fifteen-plus years of coaching, nutrition sits right alongside training for every single client I work with, not as an afterthought, but as the other half of the equation. What the research shows in athletes, I see play out constantly in everyday people: underfuelling by even a few hundred calories a day, sustained over time, quietly erodes performance and sets someone up for burnout or an overuse injury, long before it ever shows up on the scales.

If you’ve been training consistently but feel like you’re going backwards, tired, achy, unmotivated, injuries that won’t stay away, and the scales telling you nothing useful, it might not be a training problem at all. It might be time to look at what’s actually going in, over the week, not just today.

Why this one hits home for me

I’ve been stuck in this exact pattern myself. Over-trained, carrying more body fat than I needed to, and not able to get outdoors and use my body the way I wanted to. Sometimes you’ve got to feel like you’re going backwards before you can go forwards.

Eating more can feel like the last thing you should do. But it might just be the answer.

Built on years on the start line

I know this pattern personally because I’ve lived on both sides of it. Years of racing ultras, backyard formats and multi-day efforts have taught me firsthand what happens when training outpaces fuelling: first overall at the Blue Goat Backyard 50km Ultra, 16th overall at the UTA100 Mile (160km in 22 hours 36 minutes), five straight years finishing the Canberra 100km, three OXFAM Trailwalker 100km’s, and a solo, unsupported, fasted 134km trek through the Blue Mountains.

Every one of those events taught me something about pacing, fuelling and training load, and that experience goes straight into how I coach.