Why you can crash after a day you enjoyed

A crash after a day you enjoyed can feel confusing, because enjoying a day and having the energy for it are two separate things. A day can be full of joy and still take a lot of energy. Guidance pages describe pacing as a way to work with this: spreading activity through the day, building in rest, and mixing what drains you with what restores you ^[6][7]. The ideas below are about that.

Why can I feel flat after a day I enjoyed?

Autistic adults in two interview and focus group studies describe being absorbed, finding it tiring to move from one activity to the next, and, for some, needing long stretches to recover. Neither study asked about a crash after an enjoyable day ^[4][5]. This is what people described, not a full explanation.

Switching from one activity to the next took energy. In interviews with 24 autistic adults, some people said it left them exhausted ^[4].
Stopping could feel out of reach. The same people described getting so absorbed that stopping did not feel possible, and one said they forgot to eat and drink along the way ^[4]. Switching tasks and stopping when absorbed goes into this.
Some described feeling joyful, productive and full of energy while absorbed in an activity ^[4].
Tiredness made the next step harder. In six focus groups with 32 autistic adults, people described tiredness that made it harder to act, and several said they needed long stretches to recover ^[5].

If it was time with people that used up your energy, Recovering after time with people looks at what recovery can be like.

What can help when energy drops after a full day?

These ideas come from guidance pages. You can treat them as a menu and pick what suits the day.

The Royal College of Occupational Therapists describes stopping, pausing and resting between activities where possible. It also describes building rests into the activities themselves, and sitting down to rest wherever you can ^[7]. The same page suggests breaking activities into smaller tasks and spreading them through the day ^[7].

The National Autistic Society describes building in time to relax and recover ^[6]. Its page lists hobbies or interests that give energy back, and time with family or friends if that helps you recover ^[6]. It also describes setting aside time and a comfortable place to stim ^[6]. (Stimming is a repeated movement or sound that feels soothing.)

How can I plan a day around my energy?

A plan can begin before the day does. Here is what the guidance pages describe.

An energy limit. The National Autistic Society calls this energy accounting: a daily or weekly limit, an estimate of how much each activity drains, and a note of which ones restore you ^[6].
A mix of draining and restoring activities across the day or week ^[6].
A choice about what to do and what to drop. The RCOT page balances what needs doing with what you want to do, says you do not need to do everything, and says tasks can be handed off or dropped where possible ^[7].
Activities that give energy ^[7].
Things within reach. The page describes planning ahead, creating routines, and keeping what you need together and in easy reach ^[7].
Keeping track of energy. The page describes measuring and tracking how you use energy ^[7]. A short note after each day is one way to do it, if it feels useful.

A day with very little energy covers these pages in more detail.

How can you try pacing on an ordinary day?

Here are three small ideas to change until they fit you.

One example is a dinner with friends on Saturday. Before the day, a quiet slot goes into the calendar for Sunday morning. It is already there, so it does not have to be argued for later.

Another is a notes app on the phone. After each day a line goes in: what happened, and how the evening went. After a few entries, a pattern may show.

And for invitations, a sentence that says yes and leaves room:

"I'd love to come, and I might need a quiet evening afterwards."

What does research on pacing say?

Most research on pacing is with people who have chronic fatigue syndrome (CFS, also called ME/CFS, a long-term illness with severe tiredness). It is a different group from autistic adults, so it is background and not a description of you.

One study of 579 adults with CFS who wore activity monitors for 3 to 7 days sorted their activity into four patterns. About 30% were classed as "boom and bust", which is the study's own pattern label ^[1].
A 2019 study of about 430 adults with CFS or ME, drawn from four samples, compared groups by how much energy they had available and whether they stayed within it (the "energy envelope" idea). People with more available energy had higher functioning scores, but this gap was smaller for those who overexerted themselves ^[2]. The data were questionnaires from one point in time.
A 2023 review of 14 trials found that activity pacing interventions reduced fatigue in people with CFS, compared with no treatment or usual care. The improvement was larger for interventions that encouraged a gradual increase in activity ^[3]. This is evidence in people with CFS, not in autistic adults.

When can a clinician look at it?

An NHS page on tiredness suggests seeing a GP when tiredness goes on without a clear reason, affects daily life, or comes with other changes such as weight loss or changes in mood ^[8]. A clinician can look at tiredness that keeps going, together with you.

About this article

The ideas come from interview and focus group studies with autistic adults ^[4][5], guidance pages from the National Autistic Society, the Royal College of Occupational Therapists and the NHS ^[6][7][8], and studies with adults with chronic fatigue syndrome ^[1][2][3]. The three ideas under "How can you try pacing on an ordinary day?" are Mindum's own wording, and you can change them to sound like you.
The studies with autistic adults record what people say about their own experience. Most people in the Australian study were employed and well educated, and the authors note that autistic people who use little or no speech were less represented ^[4].
Tiredness has many possible causes, and a clinician can look at it with you.

Sources

King E, Beynon M, Chalder T, Sharpe M, White PD. Patterns of daytime physical activity in patients with chronic fatigue syndrome. Journal of Psychosomatic Research. 2020;135:110154. doi:10.1016/j.jpsychores.2020.110154
O'Connor K, Sunnquist M, Nicholson L, Jason LA, Newton JL, Strand EB. Energy envelope maintenance among patients with myalgic encephalomyelitis and chronic fatigue syndrome: Implications of limited energy reserves. Chronic Illness. 2019;15(1):51-60. doi:10.1177/1742395317746470
Casson S, Jones MD, Cassar J, Kwai N, Lloyd AR, Barry BK, Sandler CX. The effectiveness of activity pacing interventions for people with chronic fatigue syndrome: a systematic review and meta-analysis. Disability and Rehabilitation. 2023;45(23):3788-3802 (first published online 2022). doi:10.1080/09638288.2022.2135776
Rapaport H, Clapham H, Adams J, Lawson W, Porayska-Pomsta K, Pellicano E. "I live in extremes": A qualitative investigation of Autistic adults' experiences of inertial rest and motion. Autism. 2024;28(5):1305-1315. doi:10.1177/13623613231198916
Buckle KL, Leadbitter K, Poliakoff E, Gowen E. "No Way Out Except From External Intervention": First-Hand Accounts of Autistic Inertia. Frontiers in Psychology. 2021;12:631596. doi:10.3389/fpsyg.2021.631596
National Autistic Society. Autistic fatigue: a guide for autistic adults. Last reviewed 20 August 2020. autism.org.uk
Royal College of Occupational Therapists. Lift Up Your Everyday: Managing energy. Page undated, copyright 2026. rcot.co.uk/energy
NHS. Tiredness and fatigue. Last reviewed 2 June 2023. nhs.uk

By Mindum. An app to track and regulate emotions, energy, and focus.