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One-rep max

Your working maximum as a range, from two formulas that disagree — plus the percentages to train off.

kg
reps

Clean reps at that weight. Estimates hold to about 10 and drift badly past it.

Your estimated one-rep max

90–92.5kg

From 80 kg × 5. Epley and Brzycki disagree by 2.5 kg here, and that gap is the honest width of the estimate.

100%
92.5 kgAbout 1 rep
95%
87.5 kgAbout 2 reps
90%
82.5 kgAbout 4 reps
85%
77.5 kgAbout 6 reps
80%
72.5 kgAbout 8 reps
75%
70 kgAbout 10 reps
70%
65 kgAbout 12 reps

Worth knowing. An estimate from a set you have done, not a number to attempt. Technique fails before muscle does — a true maximum is worth attempting only with someone watching the bar.

Train with a coachA percentage table is only worth having when something decides which percentages come in which week.

How this is worked out

Two formulas, one range

Epley gives weight × (1 + reps ÷ 30). Brzycki gives weight × 36 ÷ (37 − reps). They agree at low reps and separate as reps climb, so the answer here is the span rather than a single figure implying a precision neither formula has.

Where it stops working

Both are regressions fitted to particular groups of lifters, and both drift past about 10 reps, where a set is testing endurance as much as strength. They also assume the set went to genuine failure with the technique intact.

Using the percentages

The table is rounded to the nearest 2.5 kg, because that is what loads onto a bar. Percentages are a starting point for a week's programming, not a contract — a bad night's sleep moves them more than a month of training does.

Other tools

  • Trek readinessWhat the trek asks against what you are doing now — the gap, named, and the weeks to close it.
  • Hike timeNaismith's rule, corrected for descent, pack and the stops nobody plans for.
  • Heart-rate training zonesFive zones from your own resting rate, not a formula that ignores your fitness.
  • Daily energy and proteinWhat a day actually costs you, and how much protein supports the training on top.
  • Body compositionBody fat from a tape measure, and the fat-free mass index that actually tracks your training.
  • Interval timerTabata, EMOM, hill repeats — with sound, a wake lock, and a clock that stays right in your pocket.

What would you do with this?

That is the part worth talking through, and the first conversation is free and takes half an hour.

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