Burn Fat & Build Muscle – how to change your body composition

When people talk about losing weight what they are really talking about is losing body fat and changing their body composition.  The problem is that the process of cutting back on calories in order to speed up fat loss will also result in muscle loss as well – not what you want.  

Remember you cannot exercise yourself out of a bad diet if you want to lose weight as a recent review paper highlighted. For optimal health we need a programme that focuses on building muscle and losing fat at the same time. While that might sound simple, in practice it is not always easy. Typically people cut back too hard on calories which in turn makes it hard to build muscle.  To make matters worse as we age we naturally lose muscle making it more important to focus on building not losing muscle mass.

 

The Process of Building Muscle

Whether you are a woman or a man, if you want to build muscle your body must create more muscle proteins than it loses. This requires energy (i.e. calories) and effort – you have to promote more muscle synthesis than protein (muscle) degradation.  Running for miles is not the answer.  While cardio like running with improve oxygenation and VO2 max it may not necessarily change muscle mass.

 

Resistance or strength training is more effective. This is because it recruits type 2 muscle fibres which are more involved in muscle gain.  Strength training damages muscle cells, which then stimulates protein synthesis rates to repair the tissues. Not only that but with the right training you can add new muscle cells, increasing the muscles’ size and strength. The good news is that you can maintain or even improve muscle mass when in a slight calorie deficit.

 

Strength training particularly lifting heavier and heavier weights as you progress also triggers the short-term production of hormones such as human growth hormone and testosterone that aid in muscle retention and building. Gradually putting your muscles under more stress lifting heavier loads, your muscles can adapt to get bigger and stronger.

 

Don’t Drastically Cut Calories

Cutting back too much on your calorie intake will result in both fat and muscle loss. Building muscle as body builders will know typically requires them to be in an energy surplus not a deficit. So in addition to undertaking the right training you also need to get your calorie intake and macro nutrients right. Remember your goal is to lose fat not muscle so if you are restricting calories too much you will end up losing muscle. This is more likely if you skimp on your protein intake. Studies have shown a higher protein diet is more effective at reducing body fat while preserving muscle. It also helps keep you feeling fuller for longer making it easier to stick to the plan.

 

But how much protein do you really need? Well the government guidelines are 0.8g per kg of body weight. The trouble is that this doesn’t tie in with the latest research. Many studies show that you need double or even more this to preserve muscle while losing fat.

In fact one review the researchers stated

‘Protein needs for energy-restricted resistance-trained athletes are likely 2.3-3.1g/kg of FFM scaled upwards with severity of caloric restriction and leanness’.

 

That is a lot more protein than the government guidelines! As this review focused on trained athletes, depending on your amount of training you are undertaking, you may not actually need this amount. Instead you may wish to start at around 1.2-1.6g per kg of body weight.

 

But what about the calories?  Gradual reduction in calories is much more effective than extreme restriction.  If you want to lose weight and body fat you will need to be in a calorie deficit but you don’t want to drastically cut back so that you experience muscle loss.

 

For this reason I suggest sticking to a 20-25% calorie deficit which will allow you to lose fat while preserving muscle.  To work out how many calories you need you can use one of the calorie counters such as My Fitness Pal or Lose It!

 

Once you know what calories you are burning simply multiply by 0.75 to get the calories you should be aiming for to put your body under calorie deficit.   In general a female should reduce calories by about 300 to 400 calories and males about 400 to 600 calories. Remember within this calorie allowance you need to ensure you get your protein needs.

 

You Have to Train

You won’t see significant improvements to your muscle mass if you are not training. Aim for 4-6 sessions of resistance training with the aim of adding more load as you progress.  Most people find it better to split their schedule into upper-body days and lower-body days.

 

Do HIIT Training

While resistance training will give you results, to improve fat burning add in a couple of High Intensity Interval Training sessions (HIIT) over the week – this could be on a treadmill or stationary bike. Unlike steady-state cardio, high intensity training also recruits type-2 muscle fibres helping to get more noticeable improvements.

 

Focus on Recovery and Sleep

Recovery and quality sleep is essential for improving muscle mass. If you fail to get enough sleep this can cause havoc to hormone levels, growth hormone and blood sugar levels which all play a role in maintaining and building lean muscle. Cortisol increases in times of sleep deprivation which is catabolic meaning it will inhibit weight loss and promote muscle degradation. Meanwhile, human growth hormone—which supports muscle growth and repair is at its highest during sleep.

One study showed that as little as four days of sleep deprivation reduces the body’s insulin sensitivity, increasing the risk for fat storage, while reducing the body’s levels of growth hormone.