Progressive Overload Calculator

How Double Progression Works

Most apps just add weight weekly. That works for 2 months, then you stall. RepStack's rule engine uses double progression — adding reps first within your target range (e.g., 8-12), then bumping weight only when all sets hit the ceiling.

Here's a typical progression on bench press in the 8-12 rep range:

• Session 1: 80kg × 8, 8, 8 — starting weight
• Session 2: 80kg × 9, 8, 8 — added 1 rep
• Session 3: 80kg × 10, 9, 9 — reps climbing
• Sessions 4-7: gradual climb to 80kg × 12, 12, 12
• Session 8: 82.5kg × 8, 8, 8 — weight bump, reps reset

This method generates 7 sessions of progress between weight increases instead of forcing a jump every week. The slower progression protects your joints and builds the volume base that drives hypertrophy.

The 5 Decisions the Calculator Makes

Every session, the rule engine evaluates your performance and prescribes exactly one of five actions:

• Add reps: You hit within your rep range but not the ceiling. Add 1 rep on your best set next session. The most common prescription — it means things are working.
• Increase weight: All sets hit the top of your range (e.g., all sets at 12 in an 8-12 range). Bump by the minimum increment (2.5kg barbell, 2kg dumbbell) and drop to the bottom of your range. The e1RM floor ensures you never actually get weaker.
• Hold: Some sets fell below your minimum reps. Repeat the same weight and aim for the minimum on all sets. One bad session isn't a crisis — it's normal.
• Deload (difficulty): You rated the session "very hard" (4/5 or 5/5). Drop weight by 10% and rebuild. This catches overreaching before it becomes overtraining.
• Deload (plateau): Same e1RM for 4+ sessions or two consecutive sessions below minimum reps. Drop 10% and work back up. The reset often breaks through sticking points.

When to Deload (and When Not To)

A bad session isn't a plateau. Two consecutive sessions below your rep minimum is. Sleep, stress, nutrition, and recovery all cause session-to-session variation. The rule engine doesn't overreact to a single off day.

Deloads are prescribed in three specific scenarios:

• Perceived difficulty 4+: If you rate the session "very hard" or "failed," a 10% deload prevents accumulated fatigue from compounding.
• Two sessions below minimum: If you can't hit your rep floor two sessions in a row, the weight is too heavy. Drop 10% and rebuild.
• Plateau (4+ sessions): If your estimated 1RM hasn't budged in 4 sessions despite adequate effort, something needs to change. A 10% deload with a fresh run-up often breaks through.

A deload is not a rest week. You still train at the reduced weight with full effort. The lower weight gives your joints and nervous system a recovery window while maintaining the training stimulus.

The e1RM Floor: Why You Never Actually Get Weaker

When the calculator bumps your weight, it checks that your new estimated 1RM doesn't drop below your previous best. This is the e1RM floor — a safety net unique to RepStack's rule engine.

The math: e1RM uses the Epley formula — weight × (1 + reps/30). When you move from 80kg × 12 to 82.5kg × 8, your e1RM goes from 112kg to 104.5kg. That's technically a temporary dip. The e1RM floor adjusts: if the bump weight at your target reps produces a lower e1RM, it increases the weight to preserve your strength baseline.

In practice, this means the minimum increment (2.5kg/5lbs) almost always preserves e1RM. The floor matters most for larger jumps — like when difficulty was rated "too easy" and the engine suggests a double increment.

Equipment-Specific Increments

Different equipment has different minimum load increases:

• Barbell: 2.5kg / 5lbs (smallest common plate pair)
• Dumbbell: 2kg / 5lbs (typical dumbbell step)
• Cable & Machine: 2.5kg / 5lbs (varies by equipment)
• Bodyweight: Can't auto-increment — the calculator suggests adding external load or progressing to a harder variation (e.g., push-ups → weighted push-ups → ring push-ups)

If your gym has micro plates (0.5kg / 1.25lbs), you can make even smaller jumps. Smaller increments mean more sessions of progress before you need to deload. RepStack users in the app can configure custom increments per exercise.

Why This Beats Linear Progression

Linear progression (add weight every session) works brilliantly for beginners — then it stops working entirely. After your initial neurological adaptations are exhausted (typically 2-4 months), you can't add 2.5kg every session. Attempting it leads to missed reps, form breakdown, and injury risk.

Double progression extends the progression window by adding volume (reps) before intensity (weight). You might stay at the same weight for 4-8 sessions while reps climb, then make a single weight jump. The total training stress increases steadily without the week-to-week weight pressure.

RepStack's rule engine applies this logic automatically to every exercise in your program — tracking your e1RM, detecting plateaus, and prescribing deloads when needed. This calculator gives you a taste of that logic for any single exercise.