How a Bad Night of Sleep Messes With Your Training (and Your Surfing)

Surf Ready Fitness
Dec 17, 2025
3 min read

Everyone knows sleep matters. But as surfers, we’ve all been there:

Early dawn patrol.

Late-night swell check.

Bad sleep… and you still try to train—or paddle out anyway.

The real question isn’t “Is sleep important?”

It’s how much does one bad night actually hurt your performance—and does it change what you should train?

Let’s break it down.

What Actually Happens When You Don’t Sleep Enough?

A large meta-analysis by Craven et al. looked at 69 studies and 227 performance outcomes to see how acute sleep loss (defined as ≤6 hours of sleep in a 24-hour period) affects exercise performance.

👉 You can read the study here:

Craven et al., 2022 – Effects of Acute Sleep Loss on Exercise Performance

https://pubmed.ncbi.nlm.nih.gov/35670940/

The researchers grouped performance into seven categories:

Anaerobic power
Strength & strength-endurance
Speed / power endurance
Endurance
Skill-based tasks
High-intensity intervals

Bottom line:

Performance dropped across almost every category when sleep was cut short.

But one category took the biggest hit…

Skill-Based Performance Took the Biggest L

Skill-based tasks—things that require precision, coordination, timing, and fine motor control—were affected more than anything else.

For surfers, this is huge!

We’re talking about:

Hand–eye coordination
Timing your pop-up
Reading the wave and adjusting in real time
Board control in late drops or sections
Making quick decisions under fatigue

In other words: the exact stuff that makes you a good surfer.

Strength and power still dipped, but not nearly as much.

So yes—you might still squat or deadlift “okay” on bad sleep.

But coordination-heavy work? That’s where sleep deprivation really shows up.

How Much Does Performance Actually Drop?

On average, performance declined by about 0.4% for every extra hour you were awake before training.

That sounds small… until it stacks up.

If you only get 4 hours of sleep, you could be 2–3% weaker or less sharp that day.

That’s the difference between:

Sticking a rep vs missing it
Landing a maneuver vs getting hung up
Being just a fraction late on a takeoff

Not catastrophic—but definitely noticeable.

Not All Bad Sleep Is Equal

Here’s where it gets interesting.

Worst-case scenario:

All-nighters
Going to bed really late

These had the largest negative effect on performance.

Less damaging:

Going to bed at your normal time
Waking up earlier than usual

That pattern seemed to hurt performance less.

Timing matters too

Training later in the day after poor sleep was worse than training in the morning.

Fatigue just keeps piling up as the day goes on.

Takeaway: If you slept poorly and still want to train or surf, earlier is better.

Why Does One Bad Night Mess You Up So Much?

A review by Fullagar et al. breaks down what’s happening under the hood:

👉 Fullagar et al., Sleep and Athletic Performance https://pubmed.ncbi.nlm.nih.gov/27373613/

Key issues include:

Higher stress response (sympathetic nervous system dominance)
Poor glycogen refueling
Slightly increased inflammation
Slower reaction times and worse decision-making
Reduced motor learning and coordination memory

That last point matters a lot for surfers.

If your brain isn’t consolidating movement patterns well, your timing and feel are off—even if you’re strong.

Practical Takeaways for Surfers

Here’s how I’d apply this in the real world:

Sleep loss hits coordination harder than strength
If you’re fried, it’s not the best day for complex, skill-heavy training.
One bad night won’t ruin your progress
Long-term gains depend on consistent habits, not one rough night.
Adjust, don’t skip
Reduce load, volume, or complexity instead of forcing a max-effort day.
Train earlier if you’re sleep-deprived
Morning sessions usually feel better than pushing it late.
If you have to choose
Go to bed at your normal time and wake up early.
Don’t stay up late trying to squeeze things in.