Training a Muscle 2x vs 3x a Week for Growth (New Study)

Summary by Krater

This video deconstructs a recent study comparing muscle growth from 2x versus 3x per week training across slow-twitch and fast-twitch fiber groups, and puts the findings into the broader context of scientific research on training frequency and volume. It concludes that while 3x per week training with 9 to 12 weekly sets yields slightly greater muscle growth on average, substantial hypertrophy is still achieved with lower training volumes and frequencies.

From the video

Answers: Does training muscles 3 times a week build more muscle than 2 times a week?

• muscle hypertrophy
• training frequency
• training volume
• slow-twitch muscle fibers
• fast-twitch muscle fibers
• meta-analysis

Exercises

• leg extension · machine · 3-4 sets to failure
• leg curl · machine · 3-4 sets to failure
• biceps curl · dumbbells · 3-4 sets to failure
• bench press · barbell · 3-4 sets to failure
• assisted pull-up · machine · 3 sets 8 reps
• lateral raise · dumbbells · 4 sets 12 reps
• incline reverse fly · dumbbells · 3 sets 12 reps
• standing calf raise · machine · 3 sets 8 reps
• deadlift · barbell
• front squat · barbell
• one-arm row · dumbbell
• reverse fly · dumbbells
• tricep pushdown · cable · 3 sets 10 reps

What it concludes

• Both slow-twitch and fast-twitch fiber groups grew more with 3 times per week training (9-12 weekly sets) compared to 2 times per week training (6-8 weekly sets).
• Having proportionately more fast-twitch fibers did not lead to greater gains when training 3 times per week versus 2 times per week.
• The vast majority of individuals grew better training 3 times per week, though the average extra growth was small at 1-3% for quads, hamstrings, and biceps, and 4-5% for triceps.
• Meta-analytic data shows that when total weekly set number is kept the same, splitting sets across higher or lower frequencies makes no significant difference in muscle growth.
• Performing 9 or more weekly sets per muscle group produced more muscle hypertrophy than fewer than 9 weekly sets.
• Substantial muscle hypertrophy can still be attained with lower amounts of training and lower frequencies depending on personal goals.