I had assumed lower carbs were better for me — better energy, easier weight management, sharper thinking. I'd been roughly low-carb for two years without ever testing the assumption.
So I designed a 6-week experiment: 3 weeks low-carb (under 80g/day), 3 weeks high-carb (over 250g/day). Same protein, same total calories, same workouts. Track everything.
The results pushed back on what I thought I knew.
The setup
- Weeks 1-3: under 80g carbs daily
- Weeks 4-6: over 250g carbs daily
- Protein: 150g/day in both phases
- Total calories: ~2,500/day in both phases (calories from fat replaced calories from carbs and vice versa)
- Workouts: same 4 lifts/week, same rough volume
- Tracked: weight, lifts, energy 1-5, sleep, focus 1-5
Phase 1: low carb (weeks 1-3)
Days 1-4: Felt awful. Headaches, low energy, poor workouts. The classic adaptation period.
Days 5-14: Energy stabilized. Steady, even, but not high. Workouts felt okay. Focus was actually pretty good.
Days 15-21: Settled into a rhythm. Workouts felt 80% of normal. Lifts didn't move much. Mood was even but slightly flat.
End of phase 1 numbers:
- Weight: -2.8 lb (mostly water)
- Bench top set: same as start
- Squat top set: -10 lb
- Average energy rating: 3.4/5
- Average focus rating: 3.8/5
- Sleep: same as baseline
Phase 2: high carb (weeks 4-6)
Days 22-25: Felt great immediately. Workouts felt easier. Lifts moved up.
Days 26-35: Strong workouts. Recovery faster. Energy noticeably higher than phase 1.
Days 36-42: Settled in. Workouts felt better than phase 1 baseline. Focus was about the same as phase 1 — slight surprise.
End of phase 2 numbers:
- Weight: +3.1 lb from end of phase 1, +0.3 from start of experiment
- Bench top set: +5 lb from start
- Squat top set: +5 lb from start
- Average energy rating: 4.1/5
- Average focus rating: 3.9/5
- Sleep: same as baseline
What I learned
For my workouts, more carbs were better. Strength training depends on glycogen. The numbers were clear.
For focus, both phases were roughly the same. I had assumed low-carb would make me sharper. The data didn't support that.
For energy, more carbs were better. Phase 2 averaged 0.7 points higher on a 5-point scale. That's a meaningful difference.
For weight, low-carb dropped water fast but no actual fat difference. Both phases were similar in calories.
The two-year low-carb assumption was probably wrong for me, at least for the things I cared about.
The caveats
- One person. My response is not your response.
- Subjective ratings aren't hard data. Energy and focus are noisy measurements.
- The order matters. Maybe phase 2 felt better partly because phase 1 had been hard.
- Six weeks is short. Long-term effects might differ.
What I changed
I now eat carbs around workouts (a serving of rice or oats before lifting, a serving after). On rest days, I keep carbs lower. This is roughly the cyclical approach.
It's a compromise based on data, not on a rule I read on the internet.
This isn't advice
If you're considering changing your diet, run your own experiment for a few weeks before committing to a long-term approach. Track the variables that matter to you. Then decide based on your data, not someone else's.
That's the only advice I have.
