Five variables before spring

Range comes first: full range on a light spring beats partial range on a heavy one. Then tempo — a four-second return is dramatically harder than a one-second return at the same load.

Then base of support, complexity and assistance. Each of these increases demand without changing the load, which means technique holds while difficulty rises.

Progression variables in order of usefulness
VariableHow to apply itWhy it comes first
RangeWork to full available rangeLoad is useless outside your controllable range
TempoSlow the eccentric to 3–4 secondsDoubles time under tension at the same spring
Base of supportTwo feet to one, kneeling to standingAdds stability demand, not load
ComplexityCombine limb movementsTrains coordination alongside strength
AssistanceReduce spring where it assistsCounter-intuitive but genuine progression
Spring loadAdd resistanceCrudest variable — use last

Why spring is the crude option

Adding a spring can be a 30% jump in load, which is far too coarse a step for most progressions. It also frequently changes which muscles do the work rather than making the same muscles work harder.

On assisted exercises it is worse than crude — it makes the movement easier while feeling like progress.

Reassess every six weeks

If everything in a session feels comfortable, that is the signal to change something. If nothing does, you have progressed too fast and should step back a variable.

A useful test is whether you can still hold position at the end of a set. If yes, add difficulty. If no, you are already at the right level.

Progress is not linear

Motor control improves in steps rather than smoothly. Weeks where nothing seems to change are normal and usually precede a jump.

This is why six-week review windows work better than week-to-week judgements.