How Quickly Can You Expect to See Muscle Gains?

Learn just how quickly (or slowly, depending on your outlook on life) you can expect to see gains in muscle mass after you start a muscle building program.

Brock Armstrong
5-minute read
Episode #346

Woman thinking about flexingIn today’s fast-paced society of “instant everything,” buying something online without having to leave your house isn’t enough; we also want it delivered the same day. It seems to be getting harder and harder to wait for anything. Even fitness is being rushed by people who seek out quicker and easier hacks to achieve what we used to be happy to accept as the long, hard road to greatness. Don’t get me wrong: I don’t think this is necessarily a bad thing. It’s just the way the world is moving.

Although, with the new research suggesting that erythropoietin (or EPO for short), the forbidden substance that cyclist Lance Armstrong admitted to using in his Tour de France victories, doesn’t actually work, maybe we have learned our lesson on trying to take shortcuts? Probably not ... but that is not what I wanted to get into today. We'll save that for another day.

For at least the last thirty years, trainers, athletes, and scientists alike have all assumed that the gains made in the first few weeks of a weight training program are an illusion. Not like the kind you see at a magic show or at a science museum but more of a biological slight of hand. The sport scientists all agree that the swelling caused by muscle damage is what makes muscles seem bigger and that for any real muscle size improvements you will have to wait at least six to eight weeks. Even the National Strength and Conditioning Association (NSCA) agrees with this timeline. 

Well, a new study has just been published that seeks to turn some of these old body building ideas on their head. Or at least make a significant change to that timeline. Which is good news for you folks who are in a hurry to look buff at the beach this summer!

The new study, published by the National Strength and Conditioning Association is titled “The time course of short-term hypertrophy in the absence of eccentric muscle damage.” Which is a fancy way of saying: how long it takes to build muscles when you only move the weight in one direction. Yes, I know that still seems confusing, but I will break it down for you. 

Eccentric versus Concentric

First, let’s talk about what the word eccentric means. According to the USCD page about Muscle contractions: “As the load on the muscle increases, it finally reaches a point where the external force on the muscle is greater than the force that the muscle can generate. Thus even though the muscle may be fully activated, it is forced to lengthen due to the high external load. This is referred to as an eccentric contraction.” Still confused? OK. Picture your mom doing a bicep curl with a huge dumbbell in one hand (fun, right?). When the dumbbell is moving down toward the floor, the bicep muscle is elongating which indicates an eccentric contraction. When she is moving the dumbbell up away from the floor, the muscle contracts which indicates a concentric contraction. Got it? Great! Let’s move on. Mom, you can take a knee. 

In this new study, the researchers attempted to eliminate some of the confounding effects of swelling (that occurs because of muscle tissue tearing) by having the subjects perform only concentric muscle contractions. When the test subjects were doing biceps curls, like your mom just did, they lifted the weight upward, but then a lab-coat-clad scientist jumped out of nowhere and grabbed the weight out of their hand, lowered it for them, and then handed it back before the next repetition. This routine is how they avoided the eccentric contractions that are thought to induce majority of the muscle damage.

The reason they were so concerned with limiting the muscle damage and were focusing so closely on the potential swelling that might appear after crushing a hard lifting session was so that they could dispel some very particular criticisms of an older and similar study. 

Back in 2011, a study titled “An examination of the time course of training-induced skeletal muscle hypertrophy” observed a remarkable 3.5% increase in muscle size (as measured by computerized tomography or CT scan) after just two workouts. Yes, a 3.5% increase after just two workouts!


All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Brock Armstrong Get-Fit Guy

Brock Armstrong was the host of the Get-Fit Guy podcast between 2017 and 2021. He is a certified AFLCA Group Fitness Leader with a designation in Portable Equipment, NCCP and CAC Triathlon Coach, and a TnT certified run coach. He is also on the board of advisors for the Primal Health Coach Institute and a guest faculty member of the Human Potential Institute.