75 Hard: What’s Really Happening to Your Body

Vanessa Harris
May 26
4 min read

Somewhere around day 45 of 75 Hard, I looked in the mirror and thought, Hm. I still look the same. My arms were maybe a little more toned, my waist slightly less soft. But the transformation I had secretly hoped would scream “before and after” wasn’t there. Not in any obvious way.

And then I walked up a flight of stairs without getting winded.

And I caught myself smiling after a morning workout, not because I pushed through, but because I wanted to be there.

And I realized I no longer wanted to hit the snooze button in the mornings.

That’s when it clicked. The most important progress was happening under the surface. Deep in my tissues, inside my cells, and all throughout the nervous system I’ve spent years trying to calm.

This is the kind of change that doesn’t ask to be photographed.

It asks to be felt.

A New Kind of Strong

Before I started this challenge, I was 30 pounds heavier than I’d like to be, sitting at a desk for over 40 hours a week, and working out occasionally but not consistently. I felt sluggish in my body. Foggy in my mind.

Now I’m outside every day. I’m lifting weights again. I’m drinking over 100 ounces of water and eating mindfully with intention, not perfection. But more than that, I’m remembering things I didn’t realize I had forgotten:

The way my body responds to movement like an old friend.
The rhythm of a structured day that begins in stillness.
The quiet joy of finishing what I started.

I’ve been a swimmer, a dancer, a weightlifter, a trainer. These aren’t just chapters in my past. They’re grooves in my fascia, patterns in my posture, breath memories held deep in my lungs. As I move now, my body isn’t learning something new. It’s remembering.

What’s Happening Inside (Even if You Can’t See It)

We tend to measure success by what’s visible. But what if we’re looking in the wrong places?

Here’s what’s been happening inside my body, and yours too if you’re on a similar path, even if the mirror hasn’t caught up yet:

Cellular Renewal: Every time I eat nutrient-rich food, drink water, and sleep well, I support my body’s ability to create new, healthier cells. Some cells, like gut lining and skin, turn over in days or weeks. Others, like muscle cells and mitochondria, take longer. But the change is real.
Mitochondrial Efficiency: Exercise has increased the number and efficiency of mitochondria in my cells. These are the little powerhouses responsible for converting food and oxygen into energy. This means I feel more alert, less fatigued, and more capable throughout the day.
Cardiovascular Adaptation: Walking daily and lifting weights has helped my heart become more efficient. My resting heart rate is lower. My body delivers oxygen to my muscles faster, so I recover quicker and feel less winded doing simple things.
Muscle Protein Synthesis: Lifting weights consistently has jump-started muscle repair and growth, even if it’s not obvious yet. This process takes time and trust.
Hormonal Regulation: Regular movement and consistent sleep have improved my cortisol rhythms. That means less anxiety, fewer energy crashes, and better sleep at night.
Nervous System Reset: I used to live in a near-constant state of “go.” Now, my parasympathetic nervous system, the one responsible for rest, digestion, and healing, is starting to take the lead. I can feel it in my jaw, my breath, my thoughts.

None of this showed up on the scale. But all of it changed how I move through my life.

If You’re Just Starting Out…

You don’t need a challenge to begin. You don’t need a plan so intense that it burns you out before it can build you up.

You just need to start showing up for yourself, one small act at a time. For me, 75 Hard gave me a container to do that. But the real transformation didn’t come from crossing off tasks. It came from doing them with intention.

So if you’re at the beginning of your journey, or somewhere in the middle wondering why nothing seems to be changing, keep going.

Drink your water.

Go for the walk.

Lift the weight.

Get some sun on your face.

Sleep when you’re tired.

Eat in a way that makes your body feel supported.

Pause long enough to notice what feels different, not just what looks different.

You are becoming someone your body can trust.

And that is the kind of progress you don’t need to prove.

With lightness and curiosity,

Vanessa