The InsideTracker Guide to Gaining Muscle

By Catherine Roy, January 9, 2023


Increasing muscle mass does more than just alter your physical appearance. It’s actually crucial for sustaining your health in the long term. Sufficient muscle mass helps you manage your weight, build and maintain strong bones, increase your metabolism, and keep you active as you age.

So, have we convinced you it’s time to add some lean mass? The InsideTracker platform has you covered when you choose “Strength & Power” as your goal. But here, we’ve broken down the science to provide you with some top recommendations for achieving serious #gains.


Nutrition plays a valuable role in muscle building and recovery. Learn what you need to know in The Ultimate Guide to Fueling.


Biomarkers associated with gaining muscle

As an anabolic hormone, testosterone builds muscle, improves strength, and aids in recovery. Low levels can lead to a decrease in lean muscle mass, overall energy, and competitive drive. SHBG, or sex hormone binding globulin, binds to free testosterone, impacting it’s bioavailability. Achieving an optimal level of SHBG is just as important as maintaining a healthy testosterone level.

Biomarkers 101 - Testosterone Copy (1)

Creatine Kinase, or CK, is an indicator of muscle damage. It is found inside healthy muscle cells. CK’s presence in the bloodstream means those cells have been damaged, allowing CK to seep in. Low levels are normal and expected after exercise, but constant intense workouts paired with inadequate rest can cause CK levels to stay chronically high. CK levels should return to normal 5-6 days after strenuous resistance training.

A high level of hsCRP can indicate a high level of inflammation. Inflammation breeds more inflammation. Ensuring adequate recovery after strenuous exercise can help to control inflammation levels. Chronically elevated cortisol can result in decreases in muscle mass. An opposite of testosterone, an anabolic hormone, cortisol is a catabolic hormone that works to break down muscle. Controlling the level of stress (physical and psychological) will help you build muscle.

Optimizing these biomarkers is key for gaining muscle, but not all recommendations relate to biomarkers. That's why we’ve pulled together these non-biomarker recommendations to further pack on the lean muscle.


Add strength training to your gym routine

In order to grow, a muscle must first be broken down. The most effective way to do this is by adding strength training (i.e. the use of body weight or weights) to your weekly gym sessions. Focusing on moderate weights, high repetitions, and short rest intervals has been proven to be the most effective means of training for muscle growth.1

The American College of Sports Medicine (ACSM) guidelines recommend 1-3 sets of 10-12 different exercises for 8-12 reps. Start by adding this 3 days per week.2 Focus on a total body routine using a challenging weight that targets each major muscle group: back, shoulders, biceps, triceps, abdomen, quadriceps, and hamstrings.


Time your rest periods

Adding in strength training can be a beneficial tool, and since muscle hypertrophy, or growth, is best achieved when muscles are close to fatigue, shorter rest periods between 1- 3 minutes are ideal.1

When you head to the gym, make sure you have a watch, phone, or clock in sight to ensure consistent rest periods throughout your workout. You may be tired when starting your next set, but we promise, it’ll pay off! 


Give your body the fuel it needs: protein + carbohydrates

Think of protein as the car and carbohydrates as the gas. Both are important to drive gains in lean muscle. Protein supplies your body with the amino acids necessary to generate new muscle tissue, enhance recovery, and sustain immune function during high volume training. Protein intakes ranging from 1.4-2.0 g/kg of body weight are optimal for gaining and maintaining muscle mass.3

The addition of carbohydrates to your protein source has been shown to be more advantageous in increasing muscle mass than protein alone.4 Carbohydrates stimulate the release of insulin which impacts muscle protein breakdown.


Eat before & after your workout

So when exactly should you be eating protein and carbs? Well, it really all depends on when you ate before you workout.As a general rule of thumb: you have a two hour window on either side of your workout to gain maximum benefit.5

  • Fasted workout: If you’ve gone longer than 5-6 hours without eating, you should eat immediately after your workout. A protein shake containing carbs or a mixed meal are both great options.
  • Pre- workout meal or snack: A mixed meal or snack within 1-3 hours of your workout functions as both a pre- and immediate post workout meal, since the time it takes to digest the meal will flow into the recovery period. Your next scheduled protein-rich meal (eaten 1-2 hours post-workout) will be adequate to maximize muscle growth.
  • Post workout meal: Your post workout meal, whether eaten immediately or 1-2 hours after your workout should contain 20-30 grams of complete protein to stimulate muscle protein synthesis.6 Intakes greater than 30g showed no greater improvement in stimulating synthesis.7

There is no evidence to suggest that protein powders are any better or worse than whole food protein for increasing muscle protein synthesis.5,7,8 So no matter your protein of choice, you’ll still reap the benefits.


Branched Chain Amino Acid:

For those vegetarian and vegan athletes, meeting complete protein requirements can sometimes be difficult. Branched Chain Amino Acid, or BCAA, supplements provide vegetarian and vegan athletes with the amino acids leucine, isoleucine, and valine necessary for promoting protein synthesis, muscle growth, and muscle recovery, that may be lacking in their diet.9 Protein sources such as meat and eggs provide adequate amounts of BCAAs. For meat eaters, supplementing with BCAAs has not been shown to increase muscle mass or impact recovery.



Creatine supplementation combined with resistance training yields greater increases in lean mass, total work performed, and greater gains in muscular mass compared with placebo supplementation in both trained and untrained individuals.10,11,12

Always dissolve creatine in water before taking. For the first week, take 5g four times per day for a total of 20g per day. After the first week, consume 2g per day, once a day. As always, consult your physician before beginning new supplements. Women that are pregnant or breastfeeding should not consume supplements.

Ways To Improve Sleep small

Sleep more & stress less

Sleep deprivation and high levels of stress are associated with increases in catabolic hormones, like cortisol.13 As previously mentioned, cortisol breaks down the protein found in muscle tissue into amino acids, which in turn helps your body counteract stressful situations.

Aim to get 7-8 hours of quality sleep per night in order to maximize muscle tissue growth and repair. Reducing stress through activities like yoga and meditation will also contribute to better sleep quality and management of cortisol levels.



1. “American College of Sports Medicine position stand. Progression models in resistance training for healthy adults.” Medicine and Science in Sports Exercise2009 Mar;41(3):687-708.

2. ACSM- Resistance Training for Health and Fitness.

3. Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, Landis J, Lopez H, Antonio J. “International Society of Sports Nutrition position stand: protein and exercise.” Journal of the International Society of Sports Nutrition. 2007 Sep 26;4:8.

4. Stark M, Lukaszuk J, Prawitz A, Salacinski A. “Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training.” Journal of the International Society of Sports Nutrition. 2012 Dec 14;9(1):54.

5. Aragon AA, Schoenfeld BJ. “Nutrient timing revisited: is there a post-exercise anabolic window?Journal of the International Society of Sports Nutrition. 2013 Jan 29;10(1):5.

6. Moore DR, Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, Prior T, Tarnopolsky MA, Phillips SM. “Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men.” American Journal of Clinical Nutrition. 2009 Jan;89(1):161-8.

7. Symons TB, Sheffield-Moore M, Wolfe RR, Paddon-Jones D. “A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects.” Journal of the American Dietetic Association. 2009 Sep;109(9):1582-6.

8. Witard OC1, Jackman SR, Breen L, Smith K, Selby A, Tipton KD. “Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise.” American Journal of Clinical Nutrition. 2014 Jan;99(1):86-95.

9. Howatson G, Hoad M, Goodall S, Tallent J, Bell PG, French DN. “Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study.” Journal of the International Society of Sports Nutrition. 2012 Jul 12;9:20.

10. Cribb PJ, Williams AD, Hayes A. “A creatine-protein-carbohydrate supplement enhances responses to resistance training.” Medicine and Science In Sports Exercise. 2007 Nov;39(11):1960-8.

11. Brose A, Parise G, Tarnopolsky MA. “Creatine supplementation enhances isometric strength and body composition improvements following strength exercise training in older adults.” The Journals of Gerontology. 2003 Jan;58(1):11-9.

12. Burke DG, Chilibeck PD, Parise G, Candow DG, Mahoney D, Tarnopolsky M. ”Effect of creatine and weight training on muscle creatine and performance in vegetarians.” Medicine and Science in Sports Exercise. 2003 Nov;35(11):1946-55.

13. Dattilo M, Antunes HK, Medeiros A, Mônico Neto M, Souza HS, Tufik S, de Mello MT. “Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis.” Medical Hypothesis. 2011 Aug;77(2):220-2. 

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