Periodisation: what the evidence says about linear and block plans

Your coach hands you a plan: six weeks of sets of 12, then six weeks of eights, then four weeks of fives. The bloke on the next rack has trained by feel for years and squats 180 kilograms. The real question underneath is not which periodisation model wins, but how much you gain from carving training into phases at all.

The answer is less dramatic than the seminar version, and more useful.

What we know reliably

The evidence is consistent here: progressive loading and enough total volume do the heavy lifting. Roughly 10 to 20 hard sets per muscle group per week, with the last reps close to failure, and loads that genuinely climb over months, covers most of what determines your results. How you arrange the phases sits on top of that, not underneath it.

Second, a planned progression beats standing still. A programme where weight, reps or set count change according to some rule reliably outperforms one where you grind the same three sets at the same load for months. That advantage belongs to the progression itself, not to any particular model.

Third, and this is the finding most lifters need: when linear periodisation (gradually moving from higher reps to lower reps across weeks) is compared with undulating periodisation (changing rep ranges session to session or week to week), differences in strength and muscle size are small, often barely measurable. Sometimes one edges ahead, sometimes the other. What is consistent is precisely that the gap is small.

Fourth, in strength athletes it is reasonably well established that cutting volume before a competition helps. Seven to fourteen days at roughly half the usual number of sets, with bar weight kept heavy, tends to lift performance on the day. That narrow slice of periodisation has clearer support than the full system of phases does.

What is likely but not settled

Block periodisation, where you spend longer stretches on volume, then intensity, then sharpening, is usually recommended to advanced athletes. The reasoning is sound and it is widespread practice in elite sport, but in ordinary trainees this is still poorly researched. Studies tend to show outcomes broadly similar to other well-run structured plans, without a clear winner.

It is also plausible that periodisation matters more the more advanced you are. A beginner grows on almost anything, while someone five or ten years in fights for every kilogram. That expectation follows from the general slowdown described in the piece on the ceiling on muscle growth rather than from head-to-head trials in advanced lifters.

Deloads sit in the same category. A planned lighter week every fourth to sixth week, with volume cut by a third to a half, is sensible and helps plenty of people keep going. Direct evidence that it is compulsory is surprisingly thin.

Autoregulation, where you pick the load based on how many reps you have left in reserve, looks at least as good as a fixed prescription and possibly slightly better. That fits with daily fluctuation and with the fact that two people on the same programme do not progress the same way. Still, the number of comparisons is small and the question is open.

What gets passed on wrongly

The first error is the claim that one correct model exists. When an article declares block work superior to linear, that is usually inherited coaching tradition speaking, not the data.

The second is putting too much weight on short trials. Most comparisons run six to twelve weeks, while periodisation is a tool for planning across a year. A short window cannot show the thing phases are built for.

The third is the idea that different phases pick off different fibre types, with heavy fives doing one job and sets of 15 another. It is a tidy story, but what training actually changes at the fibre level is far less selective than the story suggests, as the article on fast and slow muscle fibres explains.

The fourth is assuming a more elaborate plan must deliver more. A five-block spreadsheet feels serious, and that feeling is not neutral: part of the difference people notice comes from expectation and belief in the programme rather than from the structure.

What this means for your training

Sort the well-supported basics first. Train each muscle group two to four times a week, accumulate 10 to 20 sets weekly, use loads anywhere from 5 to 30 reps, and log your numbers so progression is a fact rather than an impression.

With that in place, choose a model on practical grounds:

• Linear suits you if you like predictability and have a fixed date ahead, such as a max test in three months.
• Undulating suits you if the same scheme bores you quickly, or if your day-to-day form swings a lot.
• Blocks suit you if you have trained for years and your joints complain when heavy singles and high volume land in the same week.

Do not swap models every few weeks. Any of them needs two to three months before it tells you anything. If you are stuck, check sleep, food, technique and set count before rewriting the structure, and if you are coming back after time away, follow a proper ramp such as the one in the piece on returning to training after a long break.

Nutrition needs less phase-matching than people imagine. Protein around 1.6 to 2.2 grams per kilogram of body weight and an energy intake that matches your goal does the same job in every model. The one sensible adjustment is to avoid a deep deficit during your highest-volume weeks.

When to see a doctor

Get checked if joint pain lasts longer than two to three weeks and does not ease with lighter training, if you get numbness, pins and needles or weakness in an arm or leg, if pain wakes you at night, if a joint swells, or if persistent fatigue comes with a sudden drop in strength, loss of appetite or a missed menstrual cycle. No arrangement of phases substitutes for an examination.

In short

• Progression and adequate volume carry the strongest evidence; phase structure is a layer on top.
• Linear and undulating models differ by small, inconsistent margins.
• Block periodisation is barely studied in recreational lifters and rests more on practice than proof.
• Cutting volume for seven to fourteen days before a competition has solid support.
• Pick a model you will actually follow for three months and measure the outcome, rather than hunting for the perfect spreadsheet.