Archive for May, 2012

Body composition explained…

Sunday, May 20th, 2012

Why is it useful to measure your body composition?

Body composition is the term used to describe the different components that make up our total body weight. It’s the ratio between our stored body fat and lean body weight (muscle, bone, organs … everything other than fat) that determines our health, tone, shape, performance, strength, metabolic rate and overall appearance. Our lean body weight (LBW) is metabolically active and fat (adipose) tissue is not.

Weight on the scales

Bathroom scales provide a measure of total weight, but don’t determine what that weight is composed of. Based only on scale weight, a 90 kilo athlete with less than 10% body fat may be considered obese by a typical weight chart. This also includes Body Mass Index (BMI) measures for the same reason. While BMI combined with waist circumference gives some indication of our physical condition, it is not as accurate as body composition.


Hydrostatic Weighing

What is it?

This is a method that involves immersing a person underwater in a large tank of water and works on the principle of displacement. LBW is more dense than water and fat tissue is less dense than water, therefore an individual with more body fat will weigh less under water and be more buoyant.


Hydrostatic weighing has long been considered a highly accurate measure of body composition.


It’s highly inaccessible, inconvenient and many more sophisticated methods are now being developed which are superseding this method.

Skinfold/Caliper Measurements

What is it?

The skin is pinched in various sites of the body using calipers to determine the thickness of sub

cutaneous (beneath the skin) body fat. Several formulas exist to calculate the sum of these measurements, incorporating our weight, height and age to estimate an overall body fat percentage.


Accessible and inexpensive. When performed by a trained and skilled professional they are up to 98% accurate.


Difficult to determine the body fat of an individual who is extremely overweight.

Accuracy takes skill and training and is commonly compromised by unskilled operators.

Bioelectrical Impedance

Bioelectrical Impedance is now a commonly used method. It sends a weak electrical current through the body. Electricity is carried by water and there is less water in fat tissue than in LBW, so it uses impedance/resistance of the current to differentiate the two. Methods range from scales you stand on to electrodes placed on the skin and handheld devices. The more accurate machines measure the entire body rather than simply standing on scales. The scales with feet electrodes only will send the current up one leg and down the other, only ‘guestimating’ you from the waist up.


Accessible, accurate, no human intervention/error, relatively inexpensive.


The readings can be affected by hydration levels so measurements should be taken under similar conditions each time for the most accuracy.

Ideal Body Weight and Percent Body Fat

A ‘healthy range’ of body fat for men is between 8 and 20 per cent, whilst for women it ranges between 20 and 30 per cent. ‘Healthy range’ means that for every per cent over or below this range, your risk of disease increases.

Over-fat has been linked to an increased risk of diabetes, heart disease and several forms of cancer, whilst under-fat (particularly in women) may increase the risk of hormonal disturbances, impaired immune function and osteoporosis.

There are two parts to reducing your body fat percentage:

1. reduce overall stored body fat

2. increase lean muscle tissue

To reach the lower end of the desired range, you must have adequate LBW to support such fat loss. Any attempt to reduce body fat using extreme measures not only leads to decreased performance, but is also likely to lead to severe health complications, such as nutrient deficiencies, infertility and injuries.

Is Body Composition Genetic?

Some aspects of where you store your body fat is genetic, however, whether you choose to store excess body fat is up to you! Your genetics are the bullet in the gun … your lifestyle is the trigger!

We lose around 3% LBW per decade after the age of 30 – that is, if we don’t exercise. In this case your body fat percentage will be increasing as you age, even if your weight doesn’t change. I often hear people use their age as justification for weighing more, but in fact we should weigh less as we age due to loss of muscle and bone density. Food for thought…

Interval training for optimum results

Friday, May 11th, 2012
by Simon Court – Senior Fitness Trainer, Aston Fitness

Fartlek and Interval Training are similar in that they are both about short bursts of increased exertion and heart rate followed by slower periods of lower exertion and heart rate to recover.

Fartlek is a Swedish word that means ‘Speed Play’. The main difference between Fartlek and Interval Training is that it is less structured, meaning that it can be less demanding than traditional Interval Training. Although, a true Fartlek runner has to be self-disciplined and motivated so as to not slack off.

Interval training is more structured requiring set time and/or distances. This is probably more advanced as the runner does not get to determine the length of the high intensity portion each time depending on how they feel.

Before adding this type of training into your regime, it is important that you have a base line fitness and know your limitations. You will find this more demanding on your body and cardiovascular system than normal constant cadence jogging.

Top tips to become a great runner:

1) Foundation: Running is a single leg sport – your entire run is spent bouncing from one leg to another. Work on your single leg strength and stability. This is fundamental to running.

2) Strength training: Dependant on our speed, our bodyweight increases by up to six times. Running also breaks down muscle so be sure to rebuild this muscle and tendon regrowth by regular strength training.

3) Mid-foot: Learn to run with a mid-foot strike. March on the spot prior to your run to reinforce this movement pattern. A heel toe traditional run acts as a brake and causes a lot of impact on the body. Ask your trainer for some tips on how to develop this running technique – just remember to take it slow at first as you will feel muscles you have not felt before after.

4) Cadence: This is how many times you hit the ground. Gone are the days of recommending a long stride. Aim for around 180 strikes per minute. Measure this by counting how many times your right foot hits the ground in 20 seconds and multiply this by 20.

5) Lean: Lean forward at the ankle without bending at the waist. This uses gravity to move you forward; not your own limited energy.

6) Mobility: Keep your big toe, foot and calves mobile. If you do not have the mobility through these areas you will not find running of any type comfortable. Ask your trainer to check for any trigger points through your feet and calves, especially if you feel any pain in your feet.



After a 5 – 10 minute warm up, speed up to a faster than comfortable pace. To increase speed, pump your arms from the shoulder not the elbow and increase your run pace. Your breathing should be very heavy. You should not be able to string any more than two words together without having to take a breath.

Pick a landmark such as a lamp-post or car and hold this pace until you reach it. Once you have reached it slow back down to your comfortable pace; one in which you can hold a conversation. As soon as your breathing has returned to close to normal pick another landmark and GO!

Try doing your Fartlek run with a buddy, it is a great way to have some fun. As Fartlek is not structured with set distances or times you can play games. Take turns at picking landmarks and race each other. You could even just say ‘GO!’ and just yell ‘STOP’ once you reach it – not letting your buddy know what it is prior.


There are a couple of different options here; distance and time. Either way each time you run you are competing with yourself and your previous times and/or distance covered.


· This can be done by setting up cones or using boundary lines on a football field. Do laps of the field, every time you hit a corner flag or midfield line alternate pass between a light recovery jog and a sprint.

· Decide before you start how many intervals you are going to complete so you don’t cheat yourself (be realistic).

· After some time you can incorporate changes of direction to bring an agility component in.


· This requires you to be able to time your intervals. Probably the most well-known interval training is Tabata Protocols. Developed in Japan these are eight rounds consisting of 20 seconds of maximal effort followed by ten seconds recovery. Once you have completed eight rounds rest for up to 2 minutes and then repeat.

· Alternatively you can set-up any time variations you wish. 30 seconds work and 30 seconds recovery is a good place to start

· Again, pre-determine how many intervals you are going to complete and stay honest.

Remember it is all about intensity. You are aiming for 85% plus max heart rate in the sprint. If you can hold a conversation you are not working hard enough.

Smartphone Tip:

There are a lot of great applications on the market to help you not only track your runs but also set-up your interval training. They work with your phones GPS so will enable you to setup both time and distance intervals. The good ones have voice-over so that they can keep you informed and motivated over the music you are listening to.

Look at:

· RunKeeper Pro

· Ghost Race

· Fitnio

· Nike Run

· Interval Run

· Plus many more


This type of training is an amazing way of getting results quickly and really challenging your body. Remember to listen to your body and not to push it too hard in the early stages of adopting this training style.

If you have any knee, hip or general pain while training stop and speak with your trainer’ you may just need a couple slight of modifications to your run style.

This is a fairly advanced style of training; it is OK to introduce it early but please seek advice from your trainer or an expert if you have any queries – or let me know and I will try to answer them.