If you do the same total amount of weightlifting each week, it doesn't matter if you split it up over several days or do it all at once—your muscles will grow the same amount. Objective measurements show that how often you train doesn't change the results as long as the total work stays the same.

Our current analysis shows that training frequency appears to have little effect on muscle growth when total weekly effort stays the same. The evidence we have reviewed leans toward the idea that splitting your workouts across multiple days or doing them all at once leads to similar results. What we have found so far comes from one assertion that we analyzed. 1 studies support, 0 studies refute. We looked at objective measurements that track muscle changes over time. These measurements suggest that how often you lift weights appears to have little effect on the outcome, as long as the total amount of work remains equal [1]. Volume just means the total amount of lifting you do each week. Our analysis of the available research indicates that this total amount matters more than the schedule you choose. We want to be clear that this is a partial view. The evidence we have reviewed so far is limited to a single data point. As more research becomes available, our understanding will likely improve. Not enough evidence exists yet to rule out other factors that might play a role. We avoid claiming this is a final answer. Instead, we report what our current review reveals. The evidence we have reviewed leans toward the idea that your weekly workout schedule can be flexible. You can spread your lifting sessions across the week or group them together without expecting a major difference in muscle growth. Focus on keeping your total weekly effort steady. Pick a schedule that fits your life and lets you stay consistent.