--- title: Not Gaining Muscle? 5 Overlooked Reasons description: Why am I not gaining muscle? Five overlooked reasons, from eating too little and too few rest days to poor sleep, hormones and gut health, and what to do. --- [![HealthBank](https://blog.healthbank.io/hs-fs/hubfs/HB_Logo.png?width=100&height=91&name=HB_Logo.png)HealthBank/Blog](https://blog.healthbank.io) [Blog](https://blog.healthbank.io) [Write for us](https://blog.healthbank.io/write-with-healthbank?utm_source=blog&utm_campaign=contributor&utm_medium=nav) [Help centre](https://help.healthbank.io) [Contact](https://www.healthbank.io/talk-to-us) [Back to HealthBank](https://dashboard.healthbank.io/app/dashboard) [Blog](https://blog.healthbank.io)  ›  Fitness # Why Am I Not Gaining Muscle? 5 Overlooked Reasons [![Robbie Clark](https://blog.healthbank.io/hs-fs/hubfs/Blog/Authors/robbie-clark-avatar.png?width=32&height=32&name=robbie-clark-avatar.png)Robbie Clark](https://www.healthbank.io/p/robbie-clark) 26 Oct 2026 Written by [Robbie Clark](https://www.healthbank.io/p/robbie-clark), BExSc (Nutrition), M (Nutr+Diet), Accredited Practising Dietitian (APD) and Exercise Scientist · Last updated 19 October 2026 · [7 references](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#references) The short answer - **Not eating enough** is the most common reason. Muscle gain stalls in an energy deficit, even if you keep getting stronger.[1](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-1) - **Too little recovery:** training hard with no rest days can lead to persistent fatigue and poorer performance.[3](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-3) - **Poor sleep:** one night without sleep lowered muscle protein building by 18%.[4](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-4) - **Hormones and gut conditions** such as low testosterone or coeliac disease can play a part. A doctor can check with blood tests.[5](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-5),[7](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-7) - Aim for about 1.6 g of protein per kg of body weight a day.[2](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-2) Training hard but not seeing the muscle you'd expect? I see this a lot. There's usually a reason muscle growth isn't happening at the pace you'd like, and it often isn't your program. Here are five reasons that are easy to overlook. ## How does muscle grow? Resistance training puts stress on your muscle fibres. In the hours and days afterwards, your body repairs them and builds new muscle protein, making the fibres thicker and stronger. Muscle grows when you build muscle protein faster than you break it down over time. That means growth happens while you recover, not while you lift, and it depends on your training, what you eat, how well you sleep and your overall health. ## 1. Are you eating enough to build muscle? Under-eating is one of the most common reasons people struggle to put on size. Many people try to lose fat and build muscle at the same time, swap between eating less and eating more, and end up with mixed results. A review of resistance training studies found that people in an energy deficit gained less muscle than those eating enough, even though their strength improved just as much. A deficit of about 2,100 kJ (500 calories) a day was enough to stop muscle gain.[1](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-1) The energy your body needs to maintain your weight is called your total daily energy expenditure. It includes the energy you use at rest (your basal metabolic rate), plus the energy used in activity and digestion. To build muscle, you need to eat a little more than this. Protein matters too: gains level off at about 1.6 g of protein per kg of body weight a day.[2](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-2) For how much extra to eat and the best foods, see [what to eat to lose fat or build muscle](https://blog.healthbank.io/blog/what-to-eat-to-lose-fat-or-build-muscle). Get support from a practitioner who helps with sports nutrition Find practitioners on HealthBank who work with sports nutrition, strength training and body composition goals. Many offer a free discovery call, online, by phone or in person. [Find a sports nutrition practitioner →](https://www.healthbank.io/practitioners?specialties%5B%5D=Sports+%26+Performance+Nutrition&specialties%5B%5D=Strength+training) ## 2. Are you training too hard without enough rest? Lifting heavy is good for building muscle, and feeling tired after a hard block of training is normal. But if you push hard without enough recovery, you can end up in a state where your performance stalls or drops for weeks or months. In more severe cases, this is called overtraining syndrome.[3](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-3) Signs include persistent fatigue, workouts feeling harder than they should, poorer performance, trouble sleeping and changes in mood. Some people also get sick more often. To prevent it, an international consensus statement recommends at least one full rest day a week, varying your training, eating enough (especially during heavy training), getting enough sleep, and easing off when you're unwell or performance drops.[3](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-3) ## 3. Are you getting enough sleep? Sleep is when much of your recovery happens. In one study, healthy young adults who went a night without sleep had 18% lower muscle protein building the next day than after a normal night. Their cortisol (a stress hormone that breaks down tissue) rose by 21% and their testosterone fell by 24%.[4](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-4) Most adults need 7–9 hours of sleep a night.[6](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-6) If you're regularly getting less, improving your sleep may help your results as much as changing your training. ## 4. Could your hormones be affecting muscle growth? Hormones such as testosterone, growth hormone, thyroid hormones and cortisol all affect how your body builds and breaks down muscle. A problem such as low testosterone or an underactive thyroid can make it harder to build muscle. If you're training consistently, eating enough and sleeping well but still not seeing results, especially if you also have low energy, low libido or other symptoms, talk to your doctor. Low testosterone is checked with a blood test taken in the morning before eating, and it should be repeated to confirm the result, as levels vary.[5](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-5) Get checked before taking anything Don't start testosterone or other hormone products without a full medical assessment. Taking them without a diagnosis can stop your body making its own testosterone.[5](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-5) ## 5. Could a gut problem be affecting how you absorb nutrients? Your gut digests and absorbs the protein, carbohydrate, fats, vitamins and minerals you need to train and recover. Some conditions can affect this. Coeliac disease, for example, can cause tiredness, unexplained weight loss, and iron and other nutrient deficiencies, as well as gut symptoms like diarrhoea, bloating and stomach pain.[7](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-7) Inflammatory bowel diseases, such as Crohn's disease, can also affect absorption. If you regularly have bloating, abdominal pain, diarrhoea, constipation, reflux or nausea, see your doctor to find the cause rather than putting up with it. ## What should you do next? Start with the basics: eat enough energy and protein, build rest days into your week, and protect your sleep. If you're doing all of that and still not progressing, or you have other symptoms, it's worth getting checked by a doctor and working with a practitioner on your training and nutrition. Get support from a practitioner who helps with sports nutrition Find practitioners on HealthBank who work with sports nutrition, strength training and body composition goals. Many offer a free discovery call, online, by phone or in person. [Find a sports nutrition practitioner →](https://www.healthbank.io/practitioners?specialties%5B%5D=Sports+%26+Performance+Nutrition&specialties%5B%5D=Strength+training) ## Frequently asked questions ### Why am I getting stronger but not bigger? If you're eating less than you need, your strength can still improve while muscle gain stalls.[1](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-1) ### Can you build muscle in a calorie deficit? It's harder. Studies show smaller muscle gains in a deficit, and a deficit of about 2,100 kJ a day can stop gains altogether.[1](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-1) ### How much protein do I need to build muscle? About 1.6 g per kg of body weight a day for most people. Eating more than that adds little extra muscle on average.[2](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-2) ### Does lack of sleep affect muscle growth? Yes. One night without sleep lowered muscle protein building by 18% and reduced testosterone.[4](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-4) ### How many rest days do I need? At least one full rest day a week, and more if you feel run down or your performance drops.[3](https://blog.healthbank.io/not-gaining-muscle-5-overlooked-reasons#ref-3) ## References **Research (PubMed)** 1. Murphy C, Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: a meta-analysis and meta-regression. *Scand J Med Sci Sports.* 2022;32(1):125–137. [PubMed 34623696](https://pubmed.ncbi.nlm.nih.gov/34623696/) 2. Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. *Br J Sports Med.* 2018;52(6):376–384. [PubMed 28698222](https://pubmed.ncbi.nlm.nih.gov/28698222/) 3. Meeusen R, Duclos M, Foster C, et al. Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine. *Med Sci Sports Exerc.* 2013;45(1):186–205. [PubMed 23247672](https://pubmed.ncbi.nlm.nih.gov/23247672/) 4. Lamon S, Morabito A, Arentson-Lantz E, et al. The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment. *Physiol Rep.* 2021;9(1):e14660. [PubMed 33400856](https://pubmed.ncbi.nlm.nih.gov/33400856/) **Australian guidelines** 1. Chan I, Ng Tang Fui M, Zajac JD, Grossmann M. Assessment and management of male androgen disorders: an update. *Aust Fam Physician.* 2014;43(5):277–282. [View source](https://www.racgp.org.au/getattachment/041c8600-4ef8-4f19-a48c-7a0057582b5d/Male-androgen-disorders.aspx) 2. Sleep Health Foundation. How much sleep do you really need? [View source](https://www.sleephealthfoundation.org.au/sleep-topics/how-much-sleep-do-you-really-need) 3. Coeliac Australia. Symptoms of coeliac disease. [View source](https://coeliac.org.au/learn/symptoms/) *This article is general information, not medical advice. Speak with your practitioner or doctor about your own training, nutrition and health.* [Fitness](https://blog.healthbank.io/tag/fitness) [![Robbie Clark](https://blog.healthbank.io/hs-fs/hubfs/Blog/Authors/robbie-clark-avatar.png?width=72&height=72&name=robbie-clark-avatar.png)](https://www.healthbank.io/p/robbie-clark) Written by **[Robbie Clark](https://www.healthbank.io/p/robbie-clark)** Robbie is a Sydney-based Accredited Practising Dietitian (APD) and Exercise Scientist with over 17 years of experience. He holds a Bachelor of Exercise Science (Nutrition) and a Master of Nutrition and Dietetics, and is the Director and Co-founder of HealthBank. [Book a free 15-min call](https://dashboard.healthbank.io/booking/attendance-modes?practitionerId=7a900b23-04a3-4c3c-b14e-e3405c1af6d7&consultationTypeId=4e536270-c479-40a5-af89-691502f4578d) [View Robbie's profile →](https://www.healthbank.io/p/robbie-clark) ## Related articles ### [Fitness What to Eat to Lose Fat or Build Muscle: Protein, Carbs and Kilojoules What to eat to lose fat and build muscle: how much protein you need, whether to cut carbs, and how many extra ... Read article →](https://blog.healthbank.io/what-to-eat-to-lose-fat-or-build-muscle) ### [Fitness What to Eat (and Not Eat) Before a Workout What to eat before a workout: when to eat, the best pre-workout meals and snacks, what to avoid to prevent ... Read article →](https://blog.healthbank.io/what-not-to-eat-before-a-workout) ### [Fitness Relationship Weight Gain: How to Stay Fit as a Couple Relationship weight gain is common. Why couples gain weight, and simple ways to eat out, share meals and keep ... 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