The Mike Mentzer workout app. Heavy Duty, without the bro-science.
Mike Mentzer built Heavy Duty on a stubborn idea most gyms still refuse: one brutally hard set per exercise, taken to momentary muscular failure, with days — sometimes a week — of recovery between sessions. Forty years later the evidence has caught up with him. Intensiq is the tracker that runs the protocol the way he described it.
Heavy Duty, in one paragraph
One set per exercise. Taken to the point where another honest rep is impossible. Rest 4–7 days between sessions of the same movement. Track the load. Only add weight when the previous set beat the target. Everything else — high-volume splits, five-day-a-week programs, "muscle confusion" — Mentzer considered noise.
Why an app finally makes it work
- Failure is measurable. Intensiq tracks bar speed and time-under-load, so "failure" is a number, not a feeling.
- Recovery is tracked. The app uses HRV and prior TUL to schedule the next session — no more guessing whether five days was enough.
- Progression is automatic. Load bumps only when the last set was honest, in-window, and to failure. No more "add 5 lbs every session" cargo-cult.
- Cadence is enforced. A 4/2/4 tempo (or Mentzer's later 10/5/10) is voiced through your headphones, so momentum can't cheat the set.
How Intensiq's routine maps to Heavy Duty
Intensiq defaults to a Big Five compound workout that lines up cleanly with Mentzer's late-career "Ideal" routine — pulldown, chest press, seated row, overhead press, leg press — one set each. Swap in a Nautilus pullover or a hammer strength row if you have the equipment; the tracker doesn't care what the machine is called, only whether the set was honest.
Who this is for
Readers of Heavy Duty II and The Wisdom of Mike Mentzer. Anyone who has spent six days a week in the gym for two years and is quietly wondering if Mentzer was right. He was. The tracker is free.
The tracker is free, forever. Twelve minutes a week is all the protocol costs you.
Start free — forever →