Vol. VII · The Training Science

If there is one non-negotiable principle in all of exercise science, it is this: the body adapts to stress, so the stress must increase over time. This is progressive overload. It can mean more weight on the bar, more reps at the same weight, more sets, shorter rest periods, or better range of motion. Without progression, the body has no reason to change. Every training method ever invented — from Milo’s calf-carrying to German Volume Training to 5/3/1 — is a variation on how to implement overload safely over time.

Muscle growth requires three stimuli: mechanical tension (heavy loads), metabolic stress (the “burn”), and muscle damage (controlled micro-tears). The current evidence (Schoenfeld 2016, 2021) suggests: 10–20 hard sets per muscle per week, taken within 1–3 reps of failure, using loads between 30–85% of 1RM. Rep range matters less than proximity to failure. The “8–12 reps for hypertrophy” rule is a useful simplification, not a biological law.

Strength is a neural adaptation: the brain learns to recruit more motor units more efficiently. Hypertrophy is a structural adaptation: the muscle fibres literally get bigger. You can get stronger without getting bigger (neural efficiency gains — common in beginners), and bigger without getting proportionally stronger (sarcoplasmic hypertrophy — common in high-rep bodybuilding). Training for strength: 1–5 reps, heavy loads, long rest (3–5 min). Training for size: 6–20 reps, moderate loads, shorter rest (60–90s).

Linear periodisation: gradually increase intensity, decrease volume over 12–16 weeks. Undulating periodisation: vary intensity within the week (heavy Monday, light Wednesday, moderate Friday). Block periodisation: 3–4 week blocks each focused on one quality (hypertrophy block → strength block → peaking block). For most non-competitive trainees, simple linear progression + weekly undulation + deload every 4–6 weeks is optimal. FitnessByMaddy’s Deload Planner calculates exactly when to back off based on your training age and weekly volume.

Meta-analysis (Schoenfeld 2016): training each muscle 2x/week produces significantly more growth than 1x/week at the same total volume. Why? Muscle protein synthesis elevates for ~48 hours post-training, then returns to baseline. If you train chest only on Monday, you have 5 days of zero growth stimulus. Train it Monday + Thursday and you double the growth windows. This is why full-body 3x/week or upper/lower 4x/week beats the traditional “bro split” for naturals. The bro split works for enhanced athletes because anabolic support extends the synthesis window. For natural trainees: frequency wins.