Measuring fat loss and lean muscle gain

Paul Johnson



Using a set of scales for measuring fat loss and lean muscle gain on a body composition training programme is outdated and flawed, says Paul Johnson MSc, BSc, SENr. Those following a programme designed to improve body composition typically use weight as a sole measure of progression. However, using weight for measuring fat loss is an outdated approach that has a number of flaws which can mask potential issues with a programme, as well as providing false information on how much progress is being made. It can also affect motivation and adherence if the numbers aren't moving in the right directions.

Why scales suck for measuring fat loss

Scales can be a useful tool when monitoring progress, however they have a number of limitations with regard to defining if the approach that you are following is providing positive results or not. Scales don't tell you what sort of weight is being lost. It is commonly assumed that when people lose weight that it comes from body fat, but sadly this is not always the case. Weight loss or gain can come from a combination of muscle, water, and carbohydrates stored within muscles and fat. During the initial stages of weight loss, muscle stores of carbohydrate (known as glycogen) become depleted. This can result in 1 – 2 lb weight loss within the first week of a diet depending on the size and dietary status of the individual. Using scales alone for measuring fat loss progress therefore provides false results.

Glycogen stores

Additionally, those looking to bulk up and increase lean mass can see an increase in scale weight as a result of increased muscle glycogen stores and increase in residual food sitting in the gut which is typically increased to meet a higher calorie intake in order to increase muscle mass. With this depletion of glycogen also comes a reduction in the amount of water that the body holds as water binds to glycogen. For every gram of carbohydrate within the body there is between 2 - 3 grams of water attached to it. This can lead to a further weight loss of 5 – 10 pounds and explains part of the reason why very low carbohydrate diets cause a rapid amount of weight to be lost in a short period of time. When calories are restricted to low levels and physical activity and aerobic exercise are increased the body will use a combination of stored energy in the form of both fat and muscle protein to meet the bodies essential energy requirements. This results in a loss of both body fat and lean muscle tissue and explains why standard weight loss approaches lead individuals to become a smaller version of their former self as their fat to muscle ratio is still relative to one another.

Factors to consider when measuring fat loss progress

When measuring fat loss progress and lean muscle gains using scales, you'll find that your weight can vary widely from day to day and week to week without anything seemly different taking place in between weigh ins. That's due to one of the below factors: Hydration levels How much you have drank that or the previous day. Stomach contents The weight of the food you ate that or the previous day. Menstrual cycle Water is more likely retained during the follicular phase of the cycle (i.e. the 12 days from menstruation to ovulation). Change in regular diet An increase in carbohydrates and / or salt with cause glycogen stored to be refilled and water to be retained. Stress This increases the hormone cortisol, which can cause excess water retention to occur, especially during times where insulin levels are increased (i.e. acute stressful situations followed by comfort eating of high fat and sugar foods). Increase in muscle mass During the initial stages of an exercise programme, it is possible for an individual to build muscle and lose fat at the same time, this is a rare occurrence for people other than beginners to exercise.

The scales lie

When these things occur, people using the scales alone for measuring fat loss typically assume they have lost or gained fat. If the weight change from week to week is greater the 2-3 pounds then the likelihood is that fat, muscle and water are being lost or gained. The larger the difference between weigh- ins the greater the shifts in fluid balance (i.e water retention or losses). Dress size and girth measurements provide more accurate monitoring tools. It can often be seen in people losing weight that the scale weight drops without much difference in inches lost or how their clothes fit, this suggests large amount of water and muscle loss without much fat loss. On the flip side of the coin, it can also been seen that scale weight appears not to me going down yet a person's clothes start to fit better. This typically occurs in people performing a regular resistance training routine while consuming a diet supplying the body with sufficient amounts of dietary protein. This directs weight to be loss more in favour of body fat while maintaining lean mass (muscle).

Useful methods for measuring fat loss and lean muscle gain

  • Girth measurements of arms, waist, hips, bust/chest or any other area important to you as an individual.
  • How a certain item of clothing fits.
  • How you think that you look in the mirror.
  • Skin fold measurements, whether these are used to estimate body fat or just as a test - retest measure, as long as they are relative to an individual then they are a valid indication of progress. Other methods of measuring body fat can also be used, but the method of testing can heavily influence the numbers provided on a test, retest basis.
  • Scales can be used in combination with other method, however only weigh yourself no more than once a week, remember the factors that can effect scales weight, aim to weigh yourself under the same condition each week (same time of day, without previously eating or drinking), don't get disheartened if the scale weigh has not change or gone up as its unlikely to be body fat unless you have had a significantly different lifestyle that week and remember that the weight could be water, glycogen or muscle to.

Things to remember

When it comes to measuring fat loss and lean muscle gain, using the scales is outdated when used as the sole measure of progress when improved body composition is the goal. Using girth measurements, skin folds, accurate body fat testing or anything else that will allow for an accurate test - retest measure will provide information as to whether progress is being made of not. Something as simple as using an item of clothing and noting changes as to how it fits can also be a valuable way of measure when used consistently. It's important not to get fixated and obsessed with the numbers of the scales are there are many factors that can influence the numbers that have little significance as to whether body composition has changed or not.

Tagged: Training

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