Plan by energy, not by the clock — match tasks to your state

Why hour-based plans fail

You plan Sunday night: Monday 9-11am report writing, 11-12 emails, 2-4pm client calls, 4-6pm reporting.

Monday 9am: brain fog, coffee not kicking in, it takes you 40 min to open the doc. By 11 you’ve just landed in the report, but now you’re supposed to do emails. 2pm, you’re completely drained from the morning, but you’re supposed to dive into the calls.

The problem: the plan was decoupled from your actual energy. You treated your brain like a linear machine producing the same at every hour. It doesn’t — and an ADHD brain even less.

Energy isn’t linear — the research

Individual chronotype

Roenneberg et al. ^[1] documented that optimal vigilance timing varies by 5-8 hours between extreme chronotypes (lark vs. owl). A true morning chronotype peaks at 8-10am; a true night chronotype peaks at 5-10pm. Forcing a chronotype to work against the grain = massive productivity loss.

The ultradian cycle

Kleitman ^[3] described as early as 1963 the Basic Rest-Activity Cycle (BRAC): ~90 minutes of vigilance followed by ~20 minutes of dip. This cycle exists in daytime too, not just during sleep. Hence the 90/20 Pomodoro format.

ADHD dopamine depletion

ADHD stimulants (methylphenidate, amphetamines) have a known action curve: peak 1-2h after intake, decline over 4-6h (IR) or 8-12h (LA). Your cognitive energy depends on your medication timing if you take any.

Additional factors

• Quality of sleep the previous night (measurable impact from 30 min of missed sleep).
• Food (post-heavy-meal slump, late-morning hypoglycemia).
• Menstrual cycle: documented impact on attention and executive function in people who menstruate, especially late luteal phase.
• Emotional load (conflict, anxiety, excitement).

5 to 8 h

gap between optimal vigilance peak of extreme chronotypes

The principle — match tasks to energy

Bijleveld & Aarts 2014 ^[2] sum up the literature: performance on cognitively costly tasks is 2 to 3 times higher during high-energy windows than during low ones. For low-energy tasks (execution, sorting, simple admin), the variation is negligible.

Practical conclusion: reserve your high-energy windows for high-energy tasks. Fill the low windows with low tasks.

Classifying tasks

HIGH energy tasks (high cognitive load)

• Creative writing, design, solving new problems.
• Negotiations, interviews, important presentations.
• Intense learning, dense reading.
• Strategic decisions.
• Difficult conversations.

Realistic daily count: 1 to 3 blocks of 60-90 min. Never 6.

MEDIUM energy tasks (moderate load)

• Routine meetings.
• Writing on a mastered topic.
• Code/document review.
• Familiar phone calls.
• Routine admin.

LOW energy tasks (low load, execution)

• Email triage.
• File sorting.
• Groceries, cleaning.
• Documentary scrolling.
• Repetitive tasks without decisions.

Important: these categories are personal. For some, phone calls are HIGH energy (social tension). For others, LOW. Don’t copy someone else’s list.

Calibration — 2 weeks of energy journal

Before planning by energy, you need to know where YOUR windows are.

You’ll discover two things:

1. Your high windows are probably shorter than you thought (2-4h/day for most ADHD adults).
2. Your low windows are probably more numerous than you thought.

That’s normal. Don’t plan 8h of HIGH energy work if you really have 3h available.

Building the hybrid plan

Example of a typical day

• 7-9am (LOW energy on waking): morning routine, breakfast, medication if prescribed, quick email triage of urgencies.
• 9-11am (HIGH peak post-medication): deep work block — writing, design, high-stakes task.
• 11am-12 (MEDIUM): meeting or call, tasks requiring interaction.
• 12-2pm (LOW post-lunch): lunch, walk, light nap, manual or admin tasks.
• 2-4pm (second HIGH peak if medication still holds): second deep work block OR, depending on your pattern, important meetings.
• 4-6pm (MEDIUM-LOW): emails, execution, prep for tomorrow.
• Evening: rest, social, decompression. No cognitive tasks.

Adjust to your chronotype and medication.

Special cases

You’re a night owl

Your HIGH windows are probably 4-10pm. Forcing a 9-5 schedule costs you dearly. Strategies:

• Negotiate flexible hours if possible.
• Protect at least 1 HIGH block in the evening for high-stakes personal tasks.
• Accept that morning 9am is LOW for you — don’t plan creative tasks.

You’re without ADHD medication

HIGH windows are shorter and less predictable. Strategies:

• Maximum 1-2 HIGH blocks per day, 60 min each.
• More LOW energy blocks planned — accept that it’s a normal part of your day.
• Lean more on body doubling and 50/10 Pomodoro to compensate.

You have a menstrual cycle

The follicular phase (post-period, week 1-2) is usually more HIGH energy. The luteal phase (last week before period) is often more LOW. Calibrate across 2-3 cycles.

Plan big HIGH blocks in the follicular phase when possible. Late luteal = softer tasks and more rest. It’s not an “excuse”, it’s a physiological data point that can be measured ^[4] .

I spent 15 years trying to “discipline” myself to work in the morning. I eventually accepted that my peak is 5-9pm. Now I do deep work in the evening, admin in the morning, and I perform 3x better. I wasn’t lazy, I was just in the wrong slot.

Common mistakes

For AuDHD folks

AuDHD energy includes sensory and social load as an extra dimension. A day at an open-plan office is more costly in energy than a day at home, even with the same cognitive load.

Add to the journal:

• Hours in a sensorially loaded environment.
• Number of unfamiliar social interactions.
• Masking level (1-10).

Classic pattern: “social-heavy” days are LOW energy days the next day. Anticipate in the plan — don’t schedule HIGH energy Tuesday if Monday was a big social day.

See also: Decompression after masking protocol.

Useful tools

Takeaways

• Cognitive energy is not linear: chronotype, ultradian cycle, medication, menstrual cycle, sleep all modulate it.
• Calibrate first: 2 weeks of journal to find YOUR windows.
• 1-3 HIGH blocks max per day, protected like appointments.
• LOW windows are real and useful — fill them with LOW tasks, not scroll.
• For AuDHD folks, include sensory and social load in the energy calculation.
• Redo a 1-week journal every 6 months to recalibrate.

Moi aussi — raconter ça

Going further

• ADHD Pomodoro — blocks adapted to each energy
• Managing hyperfocus — protect HIGH blocks
• 5-minute rule — starting when energy is missing
• Sunsama — energy-based planning app