How to Build Lean Muscle Mass

Updated: 3rd December 2024

This guide is aimed at making the process of gaining muscle a provable and predictable process, completely removing guesswork on a permanent basis. Let’s get started.

Achieving a stronger and more defined physique involves focusing on muscle building through strategies like strength training, or bodyweight exercises such as pushups. With an effective workout plan, you could significantly increase muscle tissue growth. Which in turn, could offer significant performance improvement and contribute to healthy body composition. As a virtual fitness coach, I design personalised fitness programs to achieve just this for my clients, so let’s look at your options and see how you can incorporate building muscle as part of your overall wellness strategy.

What is lean muscle?

When fitness training first piqued my interest as a teenager, the basic understanding was that to build an aesthetic body, you had to spend half your time ‘bulking’ which meant building muscle and the other half ‘cutting’ which meant losing fat, with the goal being to finish up looking muscular, with a low body fat percentage. This is what actual bodybuilders seemed to do, so a whole generation of keen exercise enthusiasts, myself included, followed suit.

Unfortunately, for many, this process led to a lot of unwanted body fat being accumulated alongside the gained muscle, I’ve documented my own journey with health & fitness. This prolonged the ‘cutting’ phase, which if not calibrated correctly, actually meant a significant loss of muscle. As you can imagine, this was rather frustrating and the total opposite of what was trying to be achieved.

Over time, fitness strategy and terminology evolved and people began to discuss things like ‘clean bulking’ which explored the idea that perhaps you didn’t need to gain all that unwanted body fat as you gained muscle, providing you could be a little more disciplined with a well-balanced diet.

Just to be clear, when someone says they want to gain lean muscle, they really mean they want to build muscle, without also gaining body fat.

Over the years as a fitness trainer, I’ve come to understand that whilst there is a lot to learn from the world of bodybuilding, the lifestyle is actually contextually inappropriate for most people, so for the purpose of this guide, I’m speaking more to busy professionals and those that are starting their fitness journey.

The benefits of building lean muscle

Physical benefits

Improved strength

Increasing your strength and gaining muscle are strongly linked. Think of them as existing on a sliding scale. For simplicity, we could call this scale ‘rep range’, and create the scale to start at 1 rep and end at 20 reps. Almost all of your strength training workouts will sit somewhere on this scale.

Think of a workout program like a carriage on a train track. If you slide it to one end, you’ll be at low reps and leaning more toward increased strength. On the other side, around the middle, you’ll be in the sweet spot for building lean muscle, and then up the higher rates, you’ll be focusing more on improved endurance. The important thing to remember is that it’s a continuum, and you could theoretically use anywhere between 1-20 reps for muscle development, we’ll get into that a little deeper shortly.

More directly though, if you get bigger muscles, you’ll produce more force as they contract, meaning you can more easily exert that force on objects. Whether that means impacting them, throwing them or with regard to strength improvement, lifting heavy weights.

Better body composition

Improving body composition is the territory of the impressive body transformations you’ll often see fitness trainers showcasing as they have helped their clients build an aesthetic body. To get this kind of striking visual change, you typically either need to gain lean muscle or achieve fat loss, it doesn’t really matter which, and ideally you would do both at the same time, which is certainly possible, particularly if you are returning to exercise after a long lay off, simply because there will be a lot more low hanging fruit on the table.

Think of it as improving your muscle-to-fat ratio, the more lean mass you have and the less body fat the leaner and more athletic you are going to look. Notice, that this has nothing to do with what you weigh. Body composition changes are where aesthetic gains are won, never on the scale.

Improved posture

As somewhat of an online fitness mentor to my clients, especially those in their 20s, it’s not uncommon for them to convey that they want to improve their self-esteem. I see exercise plans as a fantastic vehicle to achieve this, and while there is a lot to be said for improved body composition, if we’re looking for a confidence boost and want a good training ROI, turning your attention to improving posture is one of most impactful benefits of resistance training.

Better posture can be achieved through a structured exercise program that strengthens core muscles, balances muscle groups, builds shoulder stability and helps to reduce pain in the body through improved mobility. All of these often combine to correct head position, pull the shoulders back and correct abnormalities in the hip. The huge win here is that these results can be achieved in much less time than it might take to achieve a significant weight loss goal for example, as it may be the first time you’ve ever tried to strengthen the targeted muscles.

Metabolic Benefits

Improved insulin sensitivity

A huge and often overlooked benefit of increased lean body mass is that it actually contributes to improved insulin sensitivity. Here’s how, muscle tissue is the primary storage site for glucose, so the more lean muscle you have, the greater capacity you have to store glucose. When it’s stored it’s reducing the amount circulating in your blood. Muscles burn energy, even at rest. More energy demand on your body trains it to be more efficient at using insulin to move glucose into your muscle cells.

Over time, strength training makes your cells more sensitive to insulin, which is the hormone that helps regulate blood sugar levels (the significant measure for type 2 Diabetes). This means your body needs less insulin to process the same amount of glucose, and as such, you’ll have better blood sugar control.

For this reason, after 14 years of experience as a personal trainer, one of the most unfortunate ironies in fitness is that often those who are pre-diabetic or diagnosed diabetics will approach weight loss in such a restrictive manner that they will actually lose existing muscle mass. Because they had reasoned that simply losing weight would be the key to success. But as you can see, it’s a little more nuanced than that. This is why I think a personalised fitness program built by a certified fitness coach can make a huge impact on your success in fitness.

Not only that, regular exercise can contribute to fat loss as well as muscle gain, especially around the waistline where visceral fat is stored, which will also increase insulin sensitivity.

Increased metabolic rate

As we just touched on, muscle mass requires energy to maintain. In fact, a muscle cell actually requires more energy to maintain than that of a fat cell. Basically, for every ounce of muscle you gain, your body has to burn more calories to sustain it. Another call back to how restrictive dieting often leads to muscle loss.

To bring it back to a familiar fitness and meal planning metric, the more muscle you have the greater your basal metabolic rate (BMR) will be, so you can eat more calories just to break even.

Health benefits of Muscle Gain

Healthier ageing

Have you ever heard the saying ‘use it or lose it’, that’s the way it works with muscle mass. The natural ageing process typically sees us lose 3%-5% per decade after 30, it’s a process known as sarcopenia. Weightlifting is our main tool for slowing that process.

Yes, slowing that loss will help us maintain our body shape. But it’s about more than that, resistance training puts stress on our bones, counter-intuitively this is actually good for bone health because they grow stronger under well-calibrated stress, which is a process called hormesis. It’s the same concept that leads to you seeing health benefits from intermittent fasting, ice baths and the sauna.

One of the main causes of ill health in old age is linked to an event like a fall or serious bone breakage. Increased bone strength helps lower our risks of a serious injury by way of a slip or fall, simply because our leg muscles are stronger. It’s one of the simplest and most effective ways to protect your long-term health.

Extended healthspan

Based on the above we could argue that gaining lean muscle can contribute to an extended lifespan. However, there are just so many factors that go into that calculation, including luck. It’d be more comfortable saying that resistance training can play a significant role in extending our ‘healthspan’, which is the period of life in which we’re living fully mobile, healthy and independent, especially as older adults.

Cardiovascular health

OK, so the answer is in the question here, the best way to increase cardiovascular health is indeed going to be cardio workouts. But you’ll also notice an increased heart rate when you lift weights, so it’s absolutely a mechanism through which you can make your circulatory and cardiovascular systems more efficient. In turn, reducing your risk factors for heart disease. There are also many ways to make strength training exercises more intense, by shortening rest periods, increasing rep ranges and using lighter weights.

Injury prevention

So stating the obvious, you’re more likely to get injured lifting weights as a weightlifter than someone who doesn’t train. But lifting weights improves balance and stability, and strengthens the surrounding tendons and tissue around the muscles you are working. So despite all exercise having a small risk of injury what resistance training does very well is to lower your risk of getting hurt doing all of your other forms of physical activity, because you’re simply stronger and more resilient.

Stress reduction

Pursuing an increase in lean muscle mass is going to bring with it a reduction in the stress hormone cortisol. Not to mention an outlet for physical tension and a flood of exercise-induced endorphins, all of which contribute to better stress management.

Getting a little more specific as to how lean muscle gain can positively impact stress reduction, it’s actually been shown to stimulate brain-derived neurotrophic factor (BDNF), which is a protein associated with brain health and stress reliance.

How to gain muscle

Think of gaining muscle mass as a trifecta between having effective workouts in place, giving the body the building blocks it needs through following optimal nutrition advice, and then giving the body adequate rest for muscle repair. Each part of the puzzle needs to be in place, or you could wind up putting in a lot of effort, without actually building much muscle.

Muscle building methodology

How gaining muscle works

There is a lot of conflation and misunderstanding when it comes to gaining muscle, and as a fitness coach, I see it first-hand quite often. First of all, as we’ve already touched on, your exercise habits don’t exist in a vacuum, so you will need these to be in place to achieve significant progress.

Then there’s the issue of your actual workouts. It’s not enough to just do weight training. If you want to build muscle, you must be able to look at a training regime and know if it’s going to be effective. In order to do that you have to understand the basic mechanisms at play.

I’m sure I’ll say this a few times in this guide, but I think it’s worth it. You have to think critically when it comes to health & fitness to get maximal results. So yes, whilst just showing up to exercise is great and you can enjoy many of the health benefits, as a fitness coach I’m paid to deliver results, and gaining muscle is a specific outcome, so let’s discuss how to achieve it in a predictable way.

How to be sure you’ll gain muscle

To be clear then, it’s important to understand that it’s perfectly possible to exercise consistently and enjoy many physical and mental health benefits though not actually gain muscle. Once you hold that as truth, you’ll start to connect the dots and see why the details are important. Not knowing this is why so many people are frustrated with their fitness results.

To gain muscle, you have to consistently be asking more of your muscles than they are currently capable of. Think of it like this, our bodies are survival machines. We don’t unnecessarily waste energy, so you have to ‘convince’ your body that there is a survival advantage to gaining strength and muscle.

Think of it as informing your muscles that for whatever reason, the grey matter running the show has decided it’s going to be lifting heavy objects a few times per week. Assuming you continue to do that over time and also meet your requirements for nutrition and rest, you will enjoy increased muscle mass, also known as muscle hypertrophy.

To get a bit more into the exercise science, the main process at play is muscle protein synthesis (MPS) which is the process by which the body repairs damaged muscle fibers by fusing new protein molecules into them. So then, lifting weight causes microscopic tears in the fibres of the muscles, and post-exercise there is an increase in both protein breakdown and protein synthesis. If synthesis exceeds breakdown, muscle size increases.

To drive that home, your body is going to use the amino acids from your dietary protein intake to rebuild muscle through MPS, notice that this happens at rest, not during training, and wouldn’t be possible without consuming enough protein. Which is why I suggested viewing muscle gain as a trifecta, incomplete if any one element is not in place. This begs the question, why do so many people not take enough rest days and fail to manage nutrition? Because the fundamental understanding of what is required to build muscle isn’t there, that’s what I’m aiming to address with this guide.

What is progressive overload important?

The most important factor in gaining muscle consistently over time is progressive overload. Which essentially means systematically exposing your muscles to greater stress over time. This must be well-calibrated because if done correctly it keeps the body in a constant state of trying to catch up with itself. A process where the end output for you will come in the form of bigger muscles. As fitness coaches, we refer to this process as ‘over-reaching’ It’s the sweet spot we’re looking for like the strength training equivalent of the sound a golf swing sounds when you hit the ball just right.

To demonstrate, let’s say you have an exercise in your program, for example, lateral raises and the workout is asking for 3 sets of 10. In your first workout, you completed 3 sets of 10 with 4kg free weights. When you repeat that same workout, usually the following week, you would look to complete the same 3 sets of 10, but with the next available increment which would be 5kg.

The protocol is king

I tell all of my personal training clients that the protocol is king and that performance is just feedback. By which I mean that is that every workout is built of a given combination of variables the most common are:

Exercise selection: The choice of exercise in a workout program

Rep range: The number of repetitions of each exercise, forming a ‘set’ (typically 1-20)

Number of sets: The number of sets a given exercise is performed over

Training frequency: The frequency of workouts in a period of time, usually a week. Or the amount of times a muscle group is trained in that period

Training split: The way workouts are organised to focus on muscle groups e.g. total body, upper vs lower body, or a workout day for each muscle group

Rest periods: The amount of rest given between sets of an exercise

Tempo: The speed at which an exercise is performed (slower = greater time under tension)

Each of these represents a component part of a workout program, which we might call the ‘protocol’. Your goal is to maintain progressive overload throughout a certain protocol until you are physically or mentally fatigued with it, or are starting to see diminishing returns. Which typically happens after about 4-8 weeks.

You’re then best advised to take a strategic ‘de-load’ or ‘active rest’ week to allow your body to fully recover. Returning to exercise revitalised with a new workout protocol. Ensuring that at least one of the variables in the workout is changed. Offering a new opportunity for over-reach, and as such adaptation, netting you a gain in muscle. This process is common practice amongst personal trainers and strength coaches, you’ll hear it referred to as periodisation.

Best exercises for building muscle

This is an area where a lot of people make the mistake of trying to find the best exercises to gain muscle as a solve all. It’s known as the perfect pick fallacy, an idea that one exercise or training program will be the panacea and lead to fantastic progress.

I’ve been coaching people for more than a decade, both as an in-person trainer and remotely through virtual personal training, and I like to get my clients to keep things simple. The most effective exercises are fairly predictable because they will utilise the same core movement patterns in one way or another.

So look for compound exercises like squats, lunges, deadlifts, overhead presses, hip hinges, and vertical + horizontal pulling movements. This is where you want to start when building a training regime.

You’ll see a lot of theatrical exercises on social media, but the classic exercises like the bench press, back squat, barbell deadlift and military press have earned their spot as fundamentals and they aren’t going to be displaced any time soon, utilise them.

The point is to focus on the protocol, exercise selection is just a spoke on that wheel, an important one but no more than the others we’ve discussed.

The most effective workouts for gaining muscle

Choosing the right workout program is another big banana skin in fitness. Yes, it’s also susceptible to the same perfect pick fallacy as exercise selection, but it’s trickier because finding the right exercise program is a moving target.

By this I mean, you could have the perfect exercise program, built by the best personal trainer in the world, but once you reach the point of diminishing returns with it, it’s rendered at least partially ineffective. So you have an interesting situation on your hands, you’ve got a great training program, but it’s stopped working for you, so what do you do?

Well, the truth is most people settle for diminishing returns. I’ve actually met people in old-school bodybuilding gyms who have followed the same 4-day strength program for 20 years. What kind of results do you think they are getting today?

So here’s what you do, take the most effective training program that you can realistically implement (taking into account your schedule and energy levels) and see it through for 4-8 weeks. Make sure to practise progressive overload and adhere to the protocol (including strict rest periods) then introduce a new workout plan and do the same. You essentially keep doing that for years, that’s how progress is made, no secrets, no magic bullet, just consistency.

The counter-intuitive part is that you may temporarily move away from what you consider the best training regime to another, that you consider in some way inferior purely to benefit from the contrast.

Think of it this way…

In scenario one, you have an excellent program. You see it through to diminishing returns but then don’t change it. Before long, you will be stuck with mediocre results.

In scenario two, to keep it very simple you could start with the same training program. But this time after 6 weeks you move to a new one, even if for whatever reason you think it’s not quite as good. You see that through for a further 6 weeks then move back to the original protocol, and if you want to stack another factor in your favour, you could return to the original program just with different exercises.

So in scenario 1, your results dry up at week 7, but in scenario 2, you would have enjoyed 18 weeks of progress with a simple change to your training regime made at the point of diminishing returns.

Here is a list of some of the exercise regimes I’ve enjoyed excellent success with:

Though with the exception of HST, I would consider all of these intermediate to advanced. Mostly due to the significant training volume. Always a challenge if you’re new to structured exercise regimes. I’ll outline a beginner muscle-building workout shortly.

What about cardio workouts?

It would be a mistake not to include some aerobic exercise in your training regime, even if your primary goal is to gain muscle mass. This doesn’t mean you have to be out pounding the pavement, that could actually be counterintuitive with a muscle-building goal.

Try not to neglect cardiovascular training, or mobility exercises for that matter. Yes, your primary goal is hypertrophy. But I’d strongly suggest you don’t end up one-dimensional. As we touched on in the beginning, this isn’t a guide for bodybuilders. I think our goal should be to become an all-round everyday athlete.

A natural trade-off here is to include some high-intensity interval training (HIIT) which has been shown to be beneficial in as little as 10 minutes. If you have a strong preference for resistance exercise you could make the HIIT exercises resistance-based. A great example of this would be a kettlebell complex.

Other options to build muscle

You may come across advice that bodyweight training, perhaps through callisthenics can help you gain muscle mass or that yoga can help you increase your overall strength. Whilst this is technically true, as someone who is hired specifically to deliver results for my clients, I believe in taking the most linear, and predictable route to the intended result.

An analogy might be that, if you had to write an essay, you could do it on your phone and type at a rate of a few words a minute. But it would be far more efficient to use a computer with a proper keyboard.

Personally, I love sprint training. I have a bias for it because we have a number of excellent public tracks in London, on which I spent the early years of my personal training career, both for my own training and to coach my clients. For the record, I actually think track sprints are the single best fat-burning workout I’ve ever encountered. I’m also aware that it’s within the realm of exercise science that under the right circumstances one could actually build muscle through sprinting. But would I recommend it to my clients as a route to gaining muscle? Despite my bias, no. Because the technically possible route is not the same as the tried and tested, linear and predictable way to achieve your fitness goals

Resistance training is the most effective way to build muscle because the variables are controllable. Could you build an impressive physique with callisthenics routines alone? Yes, and people do. But it wouldn’t be what I would suggest, given the option of a commercial gym or even a home gym setup where we could more easily control the increments of weight we’re exposed to.

Beginner muscle-building program

A simple beginner training regime that would yield excellent results could look like this:

Two training sessions: ‘A’ = Lower body focus & ‘B’ = Upper body focus

(I’ve listed the major muscle groups targeted in each exercise)

Session A

Barbell back squat (quads, glutes hamstrings) 4 x 12

Dumbbell Romanian Deadlifts (hamstrings, glutes, lower back) 4 x 12

Dumbbell step-ups (quads, glutes, hamstrings) 3 x 20 (alternating)

Dumbbell reverse lunge (quads, glutes, abdominals) 3 x 12 (alternating)

Barbell hip thrusts (glutes, hamstrings) 4 x 12

Calf raises (calves) 3 x 20

Session B

Barbell bench press (chest, triceps, shoulders) 4 x 12

Dumbbell single arm row (lats, upper back, rear delts) 4 x 12 per arm

Barbell overhead press (shoulders, triceps, core) 4 x 12

Dumbbell shrug (traps, forearms) 4 x 12

Barbell bicep curl (biceps) 3 x 20

Tricep kickbacks (triceps) 3 x 20

30 Seconds rest between sets on all exercises.

Muscle building nutrition

Caloric intake for muscle gain

In order to gain muscle you’ve got to get proper nutrition. It’s important to be on a caloric surplus without doing so, you may simply not be eating enough calories to achieve your goal. Of course, that isn’t a licence to eat anything you want. First of all on a mathematical basis, if the goal is to stay lean you should aim for a very moderate calorie surplus, I would suggest 10-20% and no more.

You can calculate this, by finding your basal metabolic rate, adjusting it for the amount of exercise you do and then adding your chosen surplus. I have a comprehensive guide to counting macros for fitness goals if you’d like to dive a bit deeper.

Optimal macros for building muscle

The optimal macronutrient distribution for lean muscle gain is going to call for a balanced diet. We’ve discussed how protein is a critical part of the muscle-building process. Aim for 1.6-2.2 grams of protein per kilogram of body weight, from a range of high-quality protein sources. This will make up approximately 30% of your total calories.

Carbohydrate also plays a key role, being vital for fuelling your workouts and replenishing glycogen stores. These are going to make up approximately 30-40% of your overall caloric intake.

Healthy fats will make up the remainder of your calories. These support hormone production, including testosterone, a crucial hormone for gaining muscle.

This balanced approach to nutrition ensures that your exercise performance is well fuelled and you have all of the nutrients you need to facilitate both recovery and muscle gain.

For a more detailed breakdown, I have a complete guide to eating for your fitness goals.

Rest & recovery

So onto the final element in the equation, which is making sure you get proper rest. We’ve already touched on it, but it’s worth stating again that muscle isn’t built in the gym. Think of your workout a bit like a food order, if the workout was well calibrated, you’ve requested more muscle, for that to actually happen you’ve got to create the kind of environment that facilitates it or it’ll just never be delivered. We’ve discussed how to get the nutrition part in place, now let’s make sure we cover rest and recovery.

The importance of sleep

Getting adequate sleep is a crucial factor in gaining muscle because of its impact on the hormones that influence recovery. As you sleep, your body releases growth hormone, which is essential for repairing the muscle tissue damaged through exercise. Without adequate sleep, the necessary repair process will be incomplete, slowing your muscle recovery and growth. This will also have a negative knock-on effect on your workout performance over time.

It’s not just growth hormone at play, getting proper sleep also increases testosterone, which increases the rate of protein synthesis, helping to accelerate your muscle-building results.

Sleep is also interesting, in that it’s expected to happen and as far as the body is concerned an anomaly when it doesn’t. In the same way as staying hydrated, we’re supposed to get sleep, it’s generally our busy lifestyles that rob us of it. When we lack it, our bodies adapt with hormones that help us get through the day, but unfortunately just aren’t in the interest of your long-term health, which in this case is cortisol, the stress hormone.

Picture a jar full of marbles, they each represent a day’s energy. Each day you’ll take a marble out of the jar and with every good night’s sleep you put one back in. When you miss your proper sleep cycle, you don’t get to put the marble back in. If you do that too often, you’ll eventually have an empty jar. That’s where you’ll be vulnerable to burn-out and overtraining.

Managing stress for better gains

An underestimated factor in whether you’ll see results from your workouts or not is the extent to which you are able to effectively manage stress. Not only is managing stress important for your overall health but failing to do so will be to the detriment of your fitness goals because, in an evolutionary trade-off for its actual utility in an emergency, cortisol can make it both more difficult to hold onto your hard-earned muscle mass and make it more likely that you store body fat, particularly around the abdomen. The exact opposite of our fitness goals.

A muscle gain success story

I’d like to share the story of one of my online personal training clients, Antonios. He’s a busy transplant surgeon working in New York. I created a personalised training regime for him that revamped his strength training program. He gained notable muscle size over the course of three months, most notably in his chest, shoulders and arms. He recently joined me as a guest on my podcast where he explained his fitness journey in his own words. I think it’s particularly inspiring if you’ve ever felt a busy schedule was a barrier to making progress with your fitness training.

Common muscle-building mistakes

Overtraining

Counter-intuitively, doing too much exercise could stop you from seeing results from your workouts. The recovery process takes place when you are at rest not while you exercise, so if you’re overtraining or under-resting you simply won’t have all of the right pieces of the equation in place.

Lack of consistency

Exercise shouldn’t be something you repeatedly pick up and put down. In fact, over 14 years as a fitness trainer, my observation has been that a start/stop, all-or-nothing relationship with exercise is the single biggest reason people don’t see results.

You don’t have to live like a bodybuilder to gain muscle and maintain it. The goal is to create a framework around health & fitness that you can maintain no matter how busy you get. That way you’ll always be in control. This could mean adjusting your training frequency or volume, but ideally, it’s never allowed to go to nil.

No accountability

Feeling alone in your muscle-building pursuits can be difficult, it’s always great to have someone else invested in your success, whether that’s a certified professional, a training partner or someone at home who’s excited about your positive change and keen to help.

Having the accountability of a dedicated fitness trainer can offer the kind of motivation and support that can make all the difference in seeing results with your health & fitness training. If you would like to discuss working with me through remote fitness coaching, feel free to schedule a fitness consultation with me and we’ll discuss your fitness goals.

Muscle gain should be predictable

Once you know what it takes to gain muscle, you have a blueprint to follow. All you have to do is put all of the pieces in place and follow the proven methodology. Track your progress, take notes and make adjustments over time, you’ll soon see the results you’ve been after.