Spread the same hours further apart
Four sessions over a month beat four sessions over a weekend, with identical total time.
Do this
Break study or practice into shorter sessions with gaps between them - hours, then days, then weeks. Revisit material just as you are starting to forget it. Any spaced repetition app automates the timing, but a paper schedule works.
Why it works
Forgetting a little and then retrieving forces reconstruction, which strengthens storage. Massed practice keeps material in a temporarily accessible state that decays fast. The effect has been replicated for over a century across ages, materials and subjects.
Where it fails
Useless if you need the information tomorrow - cramming genuinely does work for very short horizons, it just does not last. Spacing also requires starting early, which is precisely what people who cram cannot do.
How you’ll know
Test yourself on something you learned a month ago. If it comes back with effort rather than not at all, spacing is doing its job.