Intermittent Fasting: A Useful Tool? or a Burnout Shortcut?

Since it’s January, I wanted to take a short break from the Leadville updates to talk about a popular topic in the health, wellness, and fitness world—and shed some light on how I actually implement a widely used dietary strategy: intermittent fasting (IF).

It’s been around for a while, and most of us have heard the abridged cliff notes that make it sound almost too good to be true.

“Really? All I have to do is limit my eating to a specific window and all my hopes and dreams will come true?”

That’s like reading the first page of a 57-page IKEA instruction manual and thinking, How hard could it be?

Intermittent fasting isn’t a shortcut—it’s a structure. And like any tool, it works well when applied correctly and backfires when misused.

What Intermittent Fasting Actually Does Well

When applied appropriately, intermittent fasting can be useful for three main reasons:

• It simplifies eating decisions

• It helps with calorie adherence

• It improves insulin sensitivity

That last point is the most important—and the most misunderstood.

IF often gets marketed as a fat-loss hack, but its biggest physiological benefit is giving the body intentional breaks from constant insulin signaling. In a world where many people eat from the moment they wake up until they go to bed, those breaks matter.

Where people go wrong is assuming that more restriction automatically means better results. That’s not how the body works.

IF and Weight Loss: Let’s Clear This Up

One of the main reasons people try IF is weight loss. Here’s the honest truth:

When calories and overall energy balance are equal, intermittent fasting is neither better nor worse than a traditionally structured diet. IF does not boost metabolism.

What it does do well is create boundaries. For people who struggle with constant snacking, late-night eating, or unstructured meals, those boundaries often lead to better calorie control—and that’s where fat loss actually comes from.

So if IF helps you eat more intentionally and consistently, it can be effective. If you feel it just adds more stress to your day, it won’t.

Why Insulin Sensitivity Matters in the Real World

Insulin sensitivity refers to how efficiently your body moves sugar from the bloodstream into your cells for energy. When you’re insulin sensitive, smaller amounts of insulin do the job effectively. When sensitivity is low, the body releases more insulin to achieve the same result.

In real-world terms, better insulin sensitivity usually means:

• More stable energy between meals

• Fewer cravings

• Easier fat loss without aggressive dieting

• Better recovery from training

• Improved long-term metabolic health

Intermittent fasting can support insulin sensitivity by creating regular periods where insulin levels come down. That “downtime” is beneficial—but only if the rest of your lifestyle supports it.

The Biggest Mistake: Stacking Stress on Top of Stress

This is where most people derail an otherwise good idea.

They combine intermittent fasting with high-intensity training, assuming they’ll get a better bang for their buck. In reality, this often turns into burning the candle at both ends.

Fasting is a stressor.
High-intensity exercise is also a stressor.

Even though exercise is a good stress, your nervous system doesn’t differentiate—it still responds by increasing cortisol. Now layer that on top of work stress, poor sleep, family obligations, travel, and everyday life.

The result is chronically elevated cortisol.

And here’s the key connection: chronically elevated cortisol reduces insulin sensitivity. So when IF is paired with too much intensity, it can cancel out the very benefit people are chasing.

How to Use IF Without Undermining Its Benefits

The solution isn’t complicated—it’s just not extreme.

When implementing IF, the goal should be to limit unnecessary stress while preserving movement and muscle.

This is where low- to moderate-intensity activity shines. Walking, especially short walks after meals, is incredibly effective for blood sugar control and recovery.

If you’re lifting weights, try to do it inside your eating window, ideally late morning or early afternoon. Keep the sessions productive but manageable—leave reps in the tank and walk out feeling better than when you walked in.

Some people do well with simple, every-other-day work like kettlebell swings and squats. Nothing fancy. Nothing exhausting. Just enough stimulus to maintain strength and muscle.

The goal isn’t to do more—it’s to do the correct amount.

“But I Train First Thing in the Morning…”

You can still use intermittent fasting—you just need flexibility.

Morning cortisol is naturally highest after waking. What we want to avoid is hard training at 5 a.m. followed by not eating until noon. That’s how stress compounds.

Instead, consider:

• Shortening the fast on training days

• Having a piece of fruit before training

• Getting protein in shortly afterward

On non-training days, you can extend the fast a bit longer. IF doesn’t need to look identical every day to be effective.

Who Intermittent Fasting May Not Be Right For

Intermittent fasting isn’t a one-size-fits-all strategy. While it can be useful for many people, there are situations where it may do more harm than good—at least in its traditional form.

People with a history of disordered eating should approach IF with caution. Structured fasting windows can reinforce restrictive behaviors and disrupt hunger cues, even if the intent is health-focused.

Individuals under high physical or psychological stress may also struggle with IF. If sleep is poor, work stress is high, or recovery is already compromised, adding another stressor—especially one that limits energy intake—can worsen fatigue, stall progress, and negatively impact insulin sensitivity rather than improve it.

High-volume or high-intensity athletes often need more frequent fueling to support performance and recovery. For these individuals, long fasting windows can interfere with training quality, muscle preservation, and hormonal balance unless carefully modified.

Pregnant or breastfeeding individuals should avoid intermittent fasting, as energy and nutrient needs are elevated and consistent intake is important for both parent and child.

Finally, people who are already under-fueling or chronically dieting may find that IF amplifies symptoms like low energy, irritability, poor sleep, and stalled fat loss. In these cases, improving overall intake consistency often yields better results than further restriction.

Bringing It All Together

Intermittent fasting isn’t magic—and it isn’t punishment.

Used correctly, it creates regular breaks from constant insulin signaling, improves insulin sensitivity, and helps people eat with more intention. In real life, that shows up as steadier energy, fewer cravings, better recovery, and fat loss that doesn’t require ever-increasing restriction.

Used incorrectly—stacked on top of high-intensity training, poor sleep, and chronic stress—it drives cortisol higher and can reduce insulin sensitivity, working against you instead of for you.

The goal of IF isn’t to eat less and train harder.
It’s to eat more intentionally, train intelligently, and manage stress.

When intermittent fasting supports your physiology instead of testing your willpower, it becomes a sustainable tool—not another thing you have to recover from.