Energy Balance: The Blueprint Behind Fat Loss, Muscle Gain & Peak Performance.
- Joseph Thirkhill
- Oct 2
- 4 min read
Updated: Oct 3
At The Fitness Collective, when we talk about achieving results through our small-group personal training, everything begins with a single, powerful principle: energy balance.
A simple equation, calories in vs. calories out, is the foundation for fat loss, muscle gain, and performance. Let’s break it down in a way that’s easy to understand, put into practice, and tailored to help you get results.
Calories vs Kilojoules: What’s the Difference?
Think of calories and kilojoules like miles and kilometres; two ways of measuring energy in food, just in different units.
1 kilocalorie (kcal) ≈ 4.184 kilojoules (kJ)
Both come from the macronutrients we eat - protein, carbohydrates, and fats
Each macronutrient or fuel, if you prefer, supports your goals and lifestyle differently, from fuelling your sessions and keeping you energised, to helping with recovery and building lean muscle
Unsure about Macros? Head to our blog on >> Macronutrients: The What, Why, When and How.
BMR, TDEE & TEF: What Do They Actually Mean?
If you have been, or are currently part of our Accelerator Programme or Performance Programmes, you will have heard Coaches mention BMR - your Basal Metabolic Rate. And, if you've had a nutrition consultation or a deeper conversation about your diet and what to eat, you've more than likely heard us talk about TDEE, your Total Daily Energy Expenditure or the Thermic Effect of Food - TEF.
But what do these terms actually mean, and why are they so important when it comes to getting results?
Let'd de-bunk them.
BMR (Basal Metabolic Rate) This is the energy your body burns to stay alive, think breathing, organ function, and all the things happening under the surface, even when you're at rest.
TDEE (Total Daily Energy Expenditure). This builds on your BMR, factoring in movement, workouts, steps, and general daily activity.
TEF (Thermic Effect of Food). This is the energy your body uses to digest food.
Did you know? Protein burns roughly 20–30% of its calories during digestion, compared with 5–10% for carbs and just 0–3% for fats. It's one of the key reasons why protein is so valuable when it comes to fat loss, muscle gain, and keeping your metabolism firing.
Maintain, Lose or Gain. Your Goal Determines Your Numbers.
Whether your goal is to maintain your current weight, lose body fat, or build muscle, the numbers matter, and they matter more than you might think.
We know that energy balance isn’t one-size-fits-all. It’s dynamic and personalised, depending on where you're starting from and what you’re working towards.
Understanding how much energy your body uses (your TDEE) and how to adjust your intake based on your goal is what allows you to make real, measurable progress—without guesswork or restriction.
So, what do you need to do depending on your goal?
Maintain. Eat your TDEE, in a nutshell. Not more and not less.
For many members at our West Bridgford Personal Training gym, moving into the Maintain phase comes after achieving fat loss or alongside performance training, where we move focus to recovery, muscle maintenance, and consistent energy throughout the sessions. Did you know? Maintaining allows your body to reset, recover, and perform at its best without the stress of a calorie deficit.
Fat Loss.
Create a 15 - 20% Calorie Deficit.
If your goal is fat loss, you’ll need to consume fewer calories than you burn and ensure you create a manageable, controlled and sustainable deficit.
We tend to recommend a 15–20% reduction, which usually works out to around 500 kcal per day for most people. It’s enough to drive fat loss while still fueling your training and recovery.
Did you know? If you go too aggressive at around 25-30% or more, you may experience a faster weight loss but at what cost... energy, mental well-being and even muscle mass. Studies show that a moderate calorie deficit will lead to more fat loss and better muscle preservation over time.
Muscle Gain. Eat within a 5-10% Surplus.
Ask any of our elite Personal Training team, and they'll tell you that to build muscle, your body needs fuel and stimulus. This means consuming a calorie surplus of around 5-10% of your TDEE paired with progressive resistance training, which you'll get in our Small Group Personal Training sessions.
Did you know? One of the biggest mistakes people make when trying to build muscle is eating too much, too fast. More food doesn’t mean more muscle; making smart choices and staying consistent are what count.
Can You Lose Fat and Improve Performance at the Same Time?
Absolutely. This is called body recomposition, and it’s a real sweet spot for beginners, those returning to training, or if you've hit a bit of a plateau.
So how do you get the results? You need to focus on 3 things.
High protein intake. Aim for around 30% of total calories or 1.6 g/kg of body weight
Strength training. The strongest signal your body needs to preserve muscle or build lean tissue.
Moderate calorie deficit. Enough for fat loss without tanking performance.
Did you know? Resistance and strength training can match or beat cardio for fat loss while preserving muscle mass.
Why We Use This Method at The Fitness Collective.
Our approach isn’t just backed by science; it’s built on years of experience, knowledge gained, and, importantly, real life to deliver long-term results.
Sustainable: No crash diets or extreme hunger leading to burnout.
Muscle-protective: Supports metabolism, strength, and long-term health.
Performance-focused: Fuel your training, don't starve it.
Energy Balance, Bringing It Together in Our Coaching.
Here’s how we put energy balance into practice throughout our 6-week programmes and your Fitness Collective memberships.
Calculate your TDEE with tracking and reliable formulas tailored to your body and goals.
Set your goals.
Maintain
Fat loss (−15–20%)
Lean gains (+5–10%)
Nutrition guidance around goals and lifestyle. Think high-protein, balanced macros, and easy prep meals.
Train smart with structured resistance & strength training combined with optional cardio and conditioning.
Track, monitor & adjust. As your metabolism adapts, your Fitness Collective coach will make changes so your progress never stalls.
Energy balance isn’t a trend; it’s science. Backed by years of transformation coaching, at The Fitness Collective, we teach you how to understand and apply principles like calories, BMR, TDEE, and TEF, so you can take control of your goals and achievements.
Lasting change doesn’t come from quick fixes or guesswork; it comes from understanding the process, staying consistent, and having expert coaches by your side.
