How to Build Lean Muscle Mass

Whether you’re looking to build strength, bulk, gain muscle, increase your size, or gain weight, you’ve probably heard an emphasis on building lean muscle mass. 

Technically, lean muscle is just… muscle. But when we talk about building lean muscle mass, we’re really talking about building muscle while also gaining minimal fat. 

There’s a lot of conflicting information out there on the best way to build muscle, so in this article, we’ll break it down into two main categories: how to exercise to gain muscle, and how to eat to gain muscle. 

What is lean muscle mass?

As we mentioned in the introduction, the term “lean muscle mass” is a bit of a misnomer, as all muscle is lean! 

Building lean muscle mass is the process of building muscle while adding minimal body fat – you might hear this referred to as a “lean” or “clean” bulk. 

Why is this type of muscle gain lean?

Well, gaining muscle while gaining very little additional body fat results in a higher total lean body mass. Lean mass is all the non-fat parts of your body composition: your muscle, bone, body water, internal organs, and skin. Lean mass isn’t something you can typically measure at home, but a professional DEXA scan can unlock in-depth body composition metrics. 

How do I know my lean mass?

While there are a few ways to measure or estimate your body fat percentage, getting an accurate measurement of your lean mass is a little trickier. 

A DEXA scan is a highly accurate method of gaining insight into your overall body composition, including your muscle mass and overall lean mass. A DEXA scan can measure: 

• Body fat mass
• Body fat percentage
• Muscle mass
• Muscle percentage
• Lean mass
• Fat-free mass
• Visceral fat (VAT)
• Bone mineral content (BMC)
• Bone mineral density (BMD)
• Android: gynoid ratio (a measure of fat distribution)

Other measures of lean mass – such as body fat scales – tend to have lower levels of accuracy, but can be used to track trends in your body composition over time. 

Can I build lean muscle mass and lose fat at the same time?

It’s the age-old fitness question: can you build muscle and lose fat at the same time?

To cut to the chase, the answer is yes — and no. 

If you’re just starting out with strength training, research shows that you may well be able to lose fat and build muscle simultaneously. Those sought-after “newbie gains” aren’t a myth — and many new gym-goers are encouraged by noticeable progress when they start working out. 

However, body recomposition is a complicated science, and every body is different. 

Once you’re regularly training (or if you’re starting from a place of higher muscle mass), then losing fat and building muscle at the same time becomes substantially more difficult. 

The reason for this difficulty is closely linked to another question: can you build muscle in a calorie deficit?

Building muscle requires a caloric surplus while losing fat requires a caloric deficit — you can see where this is going! Using a cycle of cutting (to decrease body fat) and bulking (to build mass) is a common method of hitting both goals — even if not exactly simultaneously. We’ll talk more about nutrition for bulking later in this article. 

Even if your main goal is to reduce body fat, aiming to maintain your muscle mass is a great way to limit the natural decrease in metabolism that occurs when we lose weight. 

What are the benefits of building lean muscle mass?

 Before we dive into how to build muscle, let’s review the top benefits of building lean muscle mass. 

Build strength

The first and most obvious benefit of building muscle is increased strength.

As you gain muscle, you’ll start to notice you’re able to complete your workouts easier, lift heavier, and see your form improve. Strength can pay off both inside and outside the gym, improving sports performance, making everyday tasks easier, boosting self-esteem, and creating a leaner look. 

Increase metabolic rate

When it comes to body recomposition, this next benefit can be hugely beneficial. 

Higher lean body mass is positively associated with reduced rates of insulin resistance and metabolic syndrome and a higher resting metabolic rate. This is largely because lean muscle requires more energy to maintain than fat – as a general rule, the more muscle you have, the more energy you’ll need.  

As you gain muscle, this can have a positive effect on your calorie expenditure and caloric needs, making it easier to meet your body recomp goals. 

Improve functional movement and posture 

While it’s a common narrative that strength training can make you less flexible, the opposite is actually true. 

A 2011 study found that full range of motion strength training was equally as effective as static stretching at improving flexibility in the participants, and other studies have found that resistance training is also linked to improved flexibility. 

Overall, strength training is a great way to increase mobility and flexibility, and even improve your posture, all while working on those muscle gains. 

To maximise flexibility as you build muscle, focus on utilising your full range of motion for each exercise. Don’t rush, maintain a neutral spine, and stay steady throughout the entire rep – including lowering the weight –  don’t let gravity do your work for you! 

Decrease risk of injury or falls 

Strength training helps to reduce injury risk by increasing strength, improving balance, and increasing range of motion. Muscle also functions as a “shock absorber”, helping protect our joints during high-impact exercises such as running, jumping, and plyometrics. 

One review of 7738 athletes found that strength training decreased the risk of injury by up to 33% – with each 10% increase in training correlating to a 4% decrease in risk. 

Similarly, strength training can help reduce the risk of falls. This is particularly relevant for older adults or those living with osteoporosis, who can face both a higher risk of falling and worse outcomes from falls. Multicomponent exercise – particularly that incorporates weight-bearing aerobic exercise and strength and resistance exercises – has been shown to have a positive effect on bone density in patients with osteoporosis. 

Part 1: How to build lean muscle mass with exercise

 Exercise is a crucial component of building muscle mass. Here are some top tips for building lean muscle:

Hit multiple sets at a medium load

If you’re new to building muscle, any weight-bearing exercise you do will likely kickstart the process of muscle gain. At this point, getting started is a great goal.  

However, for more experienced gym-goers, professional athletes, or those with a higher starting muscle mass, it can pay off to be a bit more specific about what and how you lift. 

One highly-researched method of building muscle mass is repeated sets at a medium weight – approximately 65-85% of your 1 rep maximum for a given exercise. Evidence suggests that incorporating multiple medium-weight sets encourages muscle hypertrophy (muscle growth) by increasing testosterone and HGF (human growth factor) – two hormones that impact muscle gain. 

To put this tip into action, you want to first assess your max weight for the strength exercises you’re currently training (or want to start training). 

If you’re new to strength training, ask a trainer at your gym for advice on how to assess your max weight – or ask them to supervise. Even if you feel confident, don’t jump right in and reach for the heaviest weight you can carry off the rack – assessing max strength can potentially be dangerous if not done carefully. If you’re in doubt, go lighter. 

Once you know your max weight, train multiple sets of 6-12 reps at a 65-85% capacity. 

For example, if your starting max squat weight was 100lb, you’d want to train multiple sets of 6-12 reps at a 65-85lb weight, breaking for 1-3 mins in between each set. 

As you gain strength, adapt to match your gains. 

Prioritise compound movements  

Compound movements recruit multiple muscle groups simultaneously, making them an efficient use of your training time. 

Aim to incorporate some of the following compound movements in your workouts: 

• Deadlifts (use your hamstrings, glutes, quads, lats, traps, and core muscles)
• Pull-ups (lats, triceps, biceps, traps, rear delts, and core muscles)
• Shoulder presses (shoulders, pecs, traps, and triceps)
• Push-ups (shoulders, triceps, pecs, deltoids, and core muscles)
• Squats (quads, hamstrings, glutes, calves, and core muscles)
• Bench presses (pecs, shoulders and triceps)
• Rows (lats, rhomboids, biceps, traps)

As well as saving you time in the gym, compound movements can get your heart rate going, elevate your calorie burn, and boost muscle hypertrophy. 

Don’t be afraid to incorporate some isolation movements on top of your compound moves and lifts. These can be a great option for increasing your training volume and targeting smaller muscle groups. 

Increase your training intensity, frequency, or volume 

The “best” training frequency is going to vary depending on your goals, fitness level, the equipment you have access to, the time you can dedicate to training, and whether you need to build muscle mass on a schedule or before a specific date. 

However, one factor remains consistent: if you’re working out consistently and not seeing the results you’re looking for, you have three main options: 

• Increase training intensity 
• Increase training frequency
• Increase training volume 

Training intensity is how hard you train – for strength training, this is often reflected in the weight you lift. 

Training frequency is how often you train – whether that’s 2, 3, 4, or 5+ days a week. 

Training volume is how long you train for – whether that’s 30, 45, or 60+ mins per workout. 

Switch up one of these factors at a time, and train consistently for at least 2 weeks before considering switching things up again. Remember: when it comes to building muscle, consistency is key. 

Modify movements as needed

Can’t complete an exercise? Rather than skipping tougher exercises in favour of those you can already do well, aim to incorporate lower intensity or modified versions of harder exercises to build up your strength. 

This is particularly relevant if you’re incorporating bodyweight or calisthenic exercises as a part of your strength workouts. There are endless variations and drills you can utilise to work towards doing pull-ups, chin-ups, press-ups, squats (or even handstands!) with perfect form. Practice makes perfect, and there’s no shame in not being able to complete a full movement yet. 

Don’t skip the rest days!

As you work out and build muscle, your body needs time to rest and recover. Rest days are a crucial part of any exercise regime, and over-training can sabotage your hard work, affect your form, and diminish your performance. 

To maximise muscle recovery, make sure to:

• Get consistent, good-quality sleep
• Have adequate protein pre and post-workout
• Eat a well-balanced diet
• Stay hydrated
• Avoid alcohol and tobacco 

Aim to take at least 2 rest days per week, and where you have back-to-back workout days, alternate muscle groups to encourage muscle recovery. 

Part 2: How to build lean muscle mass with nutrition

Nutrition is an essential component of any fitness goal. Let’s take a look at how to use your nutrition to maximise your muscle gain. 

Calculate your RMR and TDEE

The first step in optimising your nutrition for building lean muscle is to understand the number of calories you’re expending and consuming each day. 

You can use the My Vital Metrics BMR and TDEE calculator to estimate your basal metabolic rate and total daily energy expenditure. Plus, if you have the results of a recent DEXA scan or RMR test, adding these to the calculator will give more accurate results.

If you don’t have results from a DEXA scan or RMR test, don’t worry: you can still use the calculator. Simply add your age, height, weight, and sex to get started. Then, the calculator will ask you the type of work you do (sedentary, active, etc), the number, length, and intensity of your workouts per week, your daily step count, and the hours of sleep you get per night. 

This will give you an estimate of your TDEE – the total number of calories you would need to consume daily to maintain your current weight. 

If you’re aiming to bulk to build lean muscle mass, you can use your TDEE +10% for a conservative bulk, or your TDEE +20% for a maximal bulk. 

Track your macros 

Once you have your TDEE, tracking your food consumption is a great way to stay on track with your goal to add lean muscle mass. While overall caloric intake is important, tracking your macros for muscle gain can help fuel your workouts and encourage your body to prioritise muscle repair and growth.

Not sure where to start? Consider tracking your macros for a week to get a baseline measurement of what you’re currently eating, and adjust from there. 

You can use this macro guide for building muscle mass as a rough guide, and adapt as needed to suit your diet and goals:

• 40-60% carbohydrates
• 25-35% protein
• 15-25% fat 

While it may be tempting to cut carbs lower, adequate carbohydrate intake is essential for proper fuel for high-intensity training. Similarly, make sure to include enough healthy, unsaturated fats such as omega-3s. Fats are essential for the digestion of fat-soluble vitamins and are used by your body as fuel during higher-intensity workouts. You can get healthy fats from foods such as salmon and other fatty fish, avocado, nuts, chia seeds, and olive oil.  

Increase your protein intake

It’s an obvious tip, but an important one. Protein is essential for muscle maintenance, growth, and repair – you simply aren’t building muscle without adequate protein.

Aim to incorporate high protein foods for muscle building, such as: 

• Salmon (24.6g per 100g)
• Chicken breast (32g per 100g)
• Tinned tuna (24.9g per 100g)
• Greek yoghurt (5.7g per 100g)
• Eggs (6g per large whole egg)
• Beef steak (31g per 100g)
• Red lentils (7.6g per 100g)
• Chickpeas (7.2g  per 100g)
• Tofu (8g per 100g)
• Quinoa (12g per 100g)
• Cottage cheese (9.4g per 100g)
• Almonds (21.1g per 100g)
• Whey or casein protein powder (24-30g per scoop)
• Pea or soy protein powder (20-25g per scoop)

As you incorporate protein sources into your diet, remember that some protein sources are “complete” (containing all nine essential amino acids) while others are “incomplete” (containing some of the nine essential amino acids). If you’re choosing incomplete sources, combine them to make sure you’re consuming a complete protein source. For example, lentils, chickpeas, and quinoa are all incomplete proteins – but by combining quinoa and lentils together you can make a complete protein. 

Protein is particularly important after resistance exercise to promote muscle repair and recovery – aim to eat a post-workout snack within 30 minutes that contains both simple carbohydrates and a good quality protein source. 

Don’t drastically cut calories 

While it can be tempting to drastically cut calories, particularly if your end goal is to both lose fat and gain muscle, this can be detrimental to the goal of building muscle mass. 

Building muscle is a process that requires a caloric surplus – you need to be consuming more calories than you’re expending daily. However, where these calories come from matters. Aim to prioritise high-quality lean proteins, whole grains, and unsaturated fats. 

As mentioned earlier, a modest bulk will require you to eat approximately 10% over your TDEE. Eating below your TDEE can risk you losing muscle – not building it. 

Hit your lean muscle mass goals with specialist fitness testing at My Vital Metrics 

Whether you’re well into your bodybuilding journey or are looking to start building lean muscle mass, the team at My Vital Metrics is here to support your fitness goals. 

Our dedicated fitness and health testing lab was created to empower you to unlock your full performance potential and take control of your health. Whether you’re looking for a DEXA scan for body composition, VO2 Max testing, FatMax testing, RMR testing, a functional movement assessment, or rapid blood testing, testing at MVM is the ultimate way to maximise your gains. 

To find out more or to book your free fitness and nutritional consultation, reach out to My Vital Metrics today!