The Truth About Workouts & Women's Cycles: What the Science Actually Says

Colenso-Semple outlines that hypertrophy occurs when muscle protein synthesis exceeds breakdown over time. The primary driver is mechanical tension, which can be achieved across a wide range of loads: low‑load/high‑rep (20–30 reps) and high‑load/low‑rep (~5 reps) both produce equivalent hypertrophy when sets are taken close to failure. The old idea of a strict “strength–endurance continuum” (1–5 reps for strength, 8–12 for hypertrophy, 15+ for endurance) is outdated. She cites work from McMaster University showing that even 30‑rep sets are just as effective for muscle growth, provided the effort is high. She emphasizes that volume—total hard sets—should be increased progressively, not rigidly adhering to a fixed number from study averages.

Colenso-Semple references Stuart Phillips’ work at McMaster, noting that a minimum of 1.2 g/kg is needed for active individuals, with 1.6 g/kg being a safe upper target for optimum muscle gain. She advises that most people don’t know their lean mass, so scaling to total body weight is practical. She emphasizes that total protein and calorie intake are far more important than timing, and that protein’s satiety effect can also aid body composition. She dismisses extremely high protein fads, stating there’s no evidence they are game‑changers.

A viral claim suggests women should use shorter rest intervals to gain more muscle, while men need longer rests. Colenso-Semple says this is unsupported. Data show that if you cut rest too short, your second set performance drops (e.g., from 10 reps to 6), reducing total training volume and thus hypertrophy. Both men and women benefit from resting enough to repeat near‑maximal effort. She notes that while circuits exist, if the goal is maximizing strength or muscle size, adequate rest is critical.

Colenso-Semple emphasizes that going from nothing to anything is the biggest step. For a 55‑year‑old untrained woman, just 20 minutes a week of challenging resistance exercise can initiate muscle growth. She suggests starting with a manageable frequency and increasing when ready. She warns against rigid prescriptions from research papers, as they represent group averages; individual sustainability is more important than hitting a specific number of sets or days.