Build muscle

Why muscle mass is a longevity biomarker

Muscle is not just about looking strong. It's a metabolic organ that regulates blood sugar, stores amino acids, secretes anti-inflammatory myokines during contraction, and protects against falls, fractures, and frailty. A meta-analysis of 16 prospective studies (81,358 participants) found that low skeletal muscle mass index was associated with a 57% increased risk of all-cause mortality ^[1]. A separate meta-analysis of nearly 2 million people showed that higher muscular strength independently predicts lower death risk regardless of age ^[2]. Building and maintaining muscle is one of the most protective health investments at any age.

How muscle grows: the science of hypertrophy

Skeletal muscle hypertrophy occurs when muscle protein synthesis consistently exceeds muscle protein breakdown, producing a positive net protein balance over time ^[3]. The primary driver is mechanical tension, the force generated during resistance exercise, which activates the mTOR signalling pathway ^[4]. While metabolic stress (the "pump" from higher-rep training) and exercise-induced muscle damage may contribute, current evidence identifies mechanical tension as the dominant stimulus for hypertrophy.

A 2025 meta-regression estimated that each additional weekly set increases hypertrophy by approximately 0.24%, with 100% posterior probability that gains rise as volume rises, though with diminishing returns beyond roughly 12 sets per muscle group per week ^[5]. This confirms that volume is the primary training variable you can manipulate for growth.

Training principles that actually drive growth

Progressive overload is the non-negotiable foundation. Muscles must encounter increasing demands over time through more weight, more reps, or more sets. An umbrella review of resistance training variables concluded that at least 10 sets per muscle group per week, trained across at least two sessions, produces optimal hypertrophy ^[6]. Working in the 6-12 rep range with 60-75% of your one-rep max provides the best balance of mechanical tension and training volume, though a broader range (6-30 reps) can be effective when sets approach failure.

Compound exercises, such as squats, deadlifts, bench press, overhead press, rows, and pull-ups, should form 60-70% of your program. They recruit multiple muscle groups, allow heavier loading, and produce the greatest overall training stimulus. Isolation exercises (curls, lateral raises, leg extensions) complement compounds by targeting muscles that may be undertrained.

Periodization, proximity to failure, and recovery

Training the same way indefinitely leads to plateaus. Periodization, the systematic variation of volume, intensity, and exercise selection over weeks and months, prevents stagnation. A common approach alternates between accumulation phases (higher volume, moderate intensity) and intensification phases (lower volume, higher intensity). Deload weeks every 4-6 weeks, reducing volume by 40-50%, allow accumulated fatigue to dissipate.

Meta-regression data from 2024 shows that training closer to failure enhances hypertrophy, but the relationship is not linear ^[7]. Reserving true failure for the last set of each exercise while keeping 1-2 reps in reserve on earlier sets is a practical compromise that maximises growth stimulus without crushing recovery.

Nutrition for building muscle

A caloric surplus of 200-400 calories above maintenance provides the energy needed for muscle construction without excessive fat gain. The landmark meta-analysis by Morton et al. (49 studies, 1,863 participants) identified a protein intake breakpoint at 1.6 g/kg/day for maximising resistance-training-induced gains in fat-free mass, with the 95% confidence interval extending to 2.2 g/kg/day ^[3]. Distribute protein across 4-5 meals with 30-50 g per serving to keep muscle protein synthesis elevated throughout the day.

• Post-workout protein (within 2 hours) combined with carbohydrates replenishes glycogen and accelerates recovery, though the anabolic window is wider than previously believed (4-6 hours)
• Creatine monohydrate (5 g daily) is the most researched and effective supplement for strength and hypertrophy. A 2024 meta-analysis confirmed it significantly increases both upper-body (+4.4 kg) and lower-body strength when combined with resistance training ^[8]
• Carbohydrates fuel high-intensity training at 3-5 g/kg body weight for moderate training volume, higher during intense phases
• Sleep provides the greatest anabolic window. Growth hormone secretion peaks during deep sleep, making 7-9 hours essential for recovery and muscle repair

Building muscle for long-term health

Sarcopenia, the age-related loss of muscle mass and function, begins as early as the fourth decade and accelerates after 60. A systematic review of randomised controlled trials in older adults with sarcopenia confirmed that resistance training significantly improves muscle mass, strength, and physical performance ^[9]. A 2022 systematic review and meta-analysis also found that resistance training is associated with a 15% reduction in all-cause mortality risk, with 30-60 minutes per week being sufficient for measurable benefit ^[10].

Building a strong muscular foundation earlier in life creates a reserve that protects against falls, metabolic disease, insulin resistance, and cognitive decline as you age. Whether you're 25 or 65, progressive strength training combined with adequate protein intake is the single most effective strategy for building and preserving the muscle mass your body needs.

Common mistakes to avoid

Ego lifting with poor form increases injury risk without improving the training stimulus. Controlled eccentrics (3-4 seconds on the lowering phase) increase time under tension and maximise mechanical loading on muscle fibres. Neglecting lagging muscle groups creates imbalances that eventually cause pain or injury. Training to true muscular failure on every set leads to excessive fatigue accumulation. And skipping deload weeks is one of the most common reasons for stalled progress in intermediate lifters.