Resistance Training for Beginners: A 4-Part Series

About this series

This series is for people who want to start resistance training — or for anyone already training who wants to fix gaps in their knowledge.

If you’re tired of conflicting advice, unnecessary complexity, or fads that don’t work, this course is for you. We'll explain how muscle growth actually works. Each lesson builds on the last, covering training structure, recovery, progression, and the principles that drive long-term gains.

Everything is evidence-based and drawn from decades of research and experience. By the end, you’ll have the knowledge to create, evaluate, or adjust any resistance training programme with confidence. The content of this course reflects current consensus from exercise science research, where available — it's backed by decades of research and practice.

What’s included

• How resistance training actually works: “The Physiology”
• How to structure resistance training sessions
• Recovery, nutrition, and a few other important things
• How to progress safely and sustainably over time

What we avoid

This isn't a workout program with specific exercises or training schedules. It's educational content that’ll help you understand why programs work, and why they don't. Once you know these principles, you'll be equipped to evaluate resistance training programmes and start tailoring it your own needs.

If you want more detailed and structured information, we have a whole resource hub on exercise (which includes a lot on resistance training).

How to use this course

Each lesson in this series is a quick 5-minute read, with a small task at the end of each one. These tasks aren't strictly necessary, but doing them will help crystallise your understanding.

On individual responses

The principles in this series apply broadly, but individual responses vary. Your age, training experience, genetics, lifestyle, and dozens of other factors will influence how your body responds to training. The ranges and recommendations provided are starting points, not rigid prescriptions.

Your task for today:

Before reading further, take a moment to think about why you're interested in starting resistance training and what brought you here. Understanding your own motivation (even if it's just mere curiosity) can help you extract more value from the information ahead.

Lesson 1: The physiology of resistance training

Muscle growth doesn't happen during training. This might seem counterintuitive, but understanding this point is essential to everything that follows. When you lift weights, you're not building muscle — you're creating the conditions that will later cause muscle to grow. The actual growth processes occur between training sessions, while you're recovering, when your body adapts to the stress you've placed on it.

The three signals for growth

Researchers have identified three primary mechanisms that signal your body to build muscle:

1. Mechanical tension is the force experienced by your muscle fibres when they contract against a resistance (e.g., a dumbbell or barbell). This is the most important signal by far. When you lift a weight, your muscle fibres generate tension to move that load. This tension then triggers a wave of cellular responses that stimulate muscle growth.
2. Metabolic stress occurs when muscles work hard enough to accumulate metabolic byproducts like lactate and hydrogen ions. This is the “burning” sensation you feel during high-repetition sets. It is thought to contribute to the growth signal, though it's nowhere near as important as the mechanical tension. In fact, some scientists think that metabolic by-products don’t matter at all¹.
3. Muscle damage refers to microscopic tears in muscle fibres caused by training. While some damage may contribute to growth, it's not necessary to feel sore after every session². In fact, excessive soreness can interfere with training consistency. So, the aim of the training session should not be to “damage” your muscles. 

The adaptation process

Here's what happens after you train:

1. Your body recognises that the stress you imposed was challenging.
2. In response, it initiates repair and growth processes to handle similar stress in the future better.
3. A process called muscle protein synthesis increases, where new contractile proteins are added to existing fibres
4. Over time, these new proteins accumulate, causing muscles to grow larger and stronger.

This is referred to as an “adaptation”. Your body is essentially saying: “That was difficult. If I am going to have to lift these weights regularly, I should build more capacity so next time it's easier”. It is a hard-wired protective mechanism that's designed to prevent your muscles (and connective tissues) from tearing.

Why effort matters

For these signals to be strong enough to trigger growth, your training must be sufficiently challenging. Light weights moved casually don't create enough mechanical tension to signal the muscle to adapt. This is why training "intensity" (i.e., how hard you're working relative to your maximum capacity) matters a lot.

Current evidence suggests that training within a few repetitions of muscular failure (i.e., the point where you cannot complete another repetition with good form) maximises the growth response. You don't need to reach complete failure on every set³, but you should finish most working sets feeling like you could only manage a few more reps.

The efficiency spectrum

Muscle growth can occur across a broad range of training loads (i.e., how much weight you’re lifting). Light weights for high repetitions to heavy weights for low repetitions stimulate growth, provided your effort level is high. However, moderate loads (roughly 60-80% of your maximum for a single repetition) appear most efficient for most people. This typically corresponds to sets of six to fifteen reps per set.

What doesn't work

Training with very light loads while stopping far from failure will produce minimal growth and is inefficient. Your body has no reason to adapt if the stress is easily manageable. Similarly, training with extremely heavy loads for very few repetitions primarily develops maximal "neuromuscular" strength rather than muscle size, though there's certainly overlap. Your muscles will still grow as long as the effort is high.

The task

The next time you're at the gym, notice the difference between sets performed with genuine effort versus those performed casually. Pay attention to how challenging the final few repetitions feel. To train to, or close to, failure, with high effort, you need to know what failure and effort feel like. For beginners, you will want to do this on a machine rather than with free weights (that can come later!)

Lesson 2: Building an effective training session

Now that you understand the mechanisms behind muscle growth and what to aim for, we can discuss how to structure individual training sessions to optimise growth signals.

The warm-up: you need less than you think

The purpose of warming up is to prepare your body for the work ahead. Its aim should be to raise your muscle temperature, rehearse the movement you are about to do, and mentally prepare yourself for a high level of effort. However, the warm-up doesn't need to be elaborate or fancy.

For lighter training sessions, a general warm-up (five to ten minutes of light movement on the treadmill or a bike) provides some performance benefits, but there are better ways to do it. 

What does help is a specific warm-up: performing one or two lighter sets of the actual exercise you're about to do. This rehearses the movement "pattern" and prepares the same muscles you're about to use. If you're lifting heavy loads (above 80% of your maximum), an exercise-specific warm-up with progressively heavier weights, “a ramp up” is needed. For lighter or moderate loads, one lighter warm-up set is normally fine.

On "working" sets

After warming up, you'll perform your “working sets”. These are the challenging sets performed at high effort that actually stimulate growth. This is where the principles from the last lesson apply.

Research suggests that performing multiple sets per exercise is more effective than single sets⁴. The current evidence points to three to ten working sets per muscle group per session as an effective range. This might be distributed across one to three different exercises targeting that muscle. For example, if training your chest, you might perform two sets of a barbell press followed by two sets of dips; that's four total working sets for that muscle group.

Rest periods: longer than you think

The time between sets matters for maintaining performance "quality". Shorter rest periods (under 60 seconds) create more metabolic stress, and you’ll definitely finish workouts faster. However, short rest periods can compromise your ability to maintain your load and repetition targets across all sets.

Longer rest periods (two to three minutes) allow for more complete recovery, allowing you to lift heavier loads or complete more repetitions at a fixed load. Since mechanical tension is the primary driver of growth, maintaining performance across sets should be your main aim.

Current evidence suggests rest periods of one to three minutes represent a reasonable compromise between time efficiency and performance maintenance⁵. If you're lifting particularly heavy loads (over 90% 1RM) or performing demanding compound movements, err toward the longer end of this range — and possibly longer.

Exercise selection: compound movements first

Exercises can be classified as "compound" (i.e., involving multiple joints and muscle groups) or "isolation" (i.e., targeting a single muscle group around one joint). Example: a squat is a compound movement involving the hips, knees, and ankles. Whereas a leg extension is an isolation movement focusing primarily on the quadriceps.

Compound movements are generally more time-efficient because they work multiple muscle groups at the same time. They also allow you to handle heavier loads, creating substantial mechanical tension and a more reflective experience of the movements you do in everyday life. For these reasons, compound movements typically form the foundation of the most efficient training programs.

Isolation exercises can add value to any workout by targeting specific muscles, but they're not essential for everyone, particularly beginners or those with limited time.

Training frequency: hit multiple muscles multiple times

How you distribute your weekly training matters. Training each muscle group two or more times per week appears superior to once-weekly training for muscle growth⁶. This allows you to spread your total weekly volume across multiple sessions, maintaining higher quality and effort on each set.

This might look like two to three full-body sessions per week, or one upper-body and one lower-body session performed once or twice a week (two to four total sessions), or a push-pull-legs (PPL) “split” performed once or twice-weekly (three to six total sessions). The key principle is that each major muscle group is trained at least twice a week.

Session volume: don't overdo it

While you need sufficient volume to stimulate growth, excessively long sessions become counterproductive. Quality deteriorates as you become more fatigued, and the final bunch of sets in an extremely long session provide diminishing returns for growth⁷.

For most people, effective training sessions last 45 to 90 minutes total, including warm-up and rest periods. If your sessions regularly exceed this, consider whether you're performing too many exercises or sets per session.

Your task

If you’re currently training or plan to start soon, sketch out a basic weekly schedule: which days will you train, and which muscle groups will you work on each day? Ensure each major muscle group is trained at least twice per week. Don't worry about specific exercises yet — just the overall structure. There is nothing wrong with two full-body sessions a week⁸.

Lesson 3: What happens between training sessions

The work you do in the gym creates the stimulus for growth. What you do outside the gym determines whether that growth actually occurs.