Measuring your body fat is an important way of evaluating your diet and your training. No technique is accurate and all approaches are estimates based on indirect measures. However, there are a number of cost effective and practical approaches you can use. Personally, I use [[Skulpt]] and [[Body Fat Scales]] to track moving daily changes, and periodic DEXA scans to calibrate. ==Skinfold Calipers==
''Main article: [[Skinfold Calipers]]''
This is the cheapest way of getting a viable estimate of your own body fat. The calipers are extremely cheap ($5 from [http://go.fellrnr.com?id=35454X937677&xs=1&url=http%3A%2F%2Fwww.amazon.com%2FAccu-Measure-Fitness-3000-Personal-Tester%2Fdp%2FB000G7YW74 Amazon.com]) and directly measure your body fat. They do require some practice to get repeatable results, but the price, performance and convenience makes them an ideal starting point.
[[File:Skinfold-4.jpg|none|thumb|250px|Accu-measure calipers in action]]
==Body Fat Scales==These Bioelectrical Impedance Analysis (BIA) scales use an imperceptible electrical signal to calculate the amount of water in the body. From this Total Body Water (TBW), it is possible to estimate body fat. This makes these scales quick and easy to use, but their accuracy is quite poor. The level of hydration has a significant impact on the reading, so readings need to be taken at the same time of day with the same level of hydration. The ''Main article: [[Book Review - The 4 Hour Body|4 Hour BodyFat Scales]] recommend drinking 1.5 liters (3 pints) of water, waiting 30 minutes, urinating and then taking a measurement. The biggest problem for an athlete is that BIA is particularly inaccurate when fat free mass, including glycogen, changes<ref name="BIA1"/><ref name="BIA2"/>. I've noticed that the day after a long run, the scales claim a much larger loss of body fat than is reasonable. '
I categorize these These scales into three types. ===Lower Body Only===Most use an imperceptible electrical signal to estimate body fat . This makes these scales have electrodes only on the feetquick and easy to use, so and the electric current only goes from one foot to the other. This only measures the lower part accuracy of the body, not scales that measure from the whole bodyhands and feet is quite reasonable. I have recommend the Tanita BF680 Omron HBF-510, which retails for about $60-$65 on [http://www.amazon.com/TanitaOmron-BF680HBF-Scale510W-Composition-Monitor-AthleticScale/dp/B000094ZGH $60B001IV61J4 Amazon.com]. [[File:Omron HBF-510.jpg|none|thumb|200px|The most cost effective body fat scale, the Omron HBF-510.]]=Skulpt=''Main article: [[Skulpt]]''
http://ecx.images-amazon.com/images/I/41CNM5C5HSL._SS400_.jpg ===Full Body BIA Scales===These Skulpt uses a similar principle to body fat scales also use BIA, but have sending an imperceptible electrical current through the skin. Instead of measuring overall body fat through 2 or 4 electrodes on the hands as well as the feetyour limbs, giving a Skulpt uses 12 electrodes close together to measure across the whole body. In my experience, these scales show changes in body fat far better than the BIA scales that read from the feet only. I have the Omron HBF-510 which retail for [http://www.amazon.com/Omron-HBF-510W-Composition-Monitor-Scale/dp/B001IV61J4 $60]. http://ecx.images-amazon.com/images/I/41yvY8JWRdL._SS500_.jpg ===Segmental Body Fat Scales===The latest Tanita scales use two frequencies over an area of electrical signal and use electrodes for the hands and feet. I have not tried these scales as they are expensive about 2" x 3" ([http://www.thecompetitiveedge.com/shop/item/123-productId.184549503_123-catId.176160808.html $300]5cm x 8cm). If these scales could transfer You then use the measurements sensor up to a PC via bluetooth24 different body locations. This provides more information about body fat in specific locations, I'd be tempted to get one. http://www.tanita.com/data/Image/products/ImageResize/Ironman---BC-558_l.jpg ===Comparison of Lower Body and Full Body Scales===Over the years I have found lower body scales show that weight loss is disproportionately from non-fat when other measures show fat levels stayed constant or dropped. Here is a recent comparison of weight loss indications from the Tanita and Omronreasonable agreement with DEXA. As you can seeThe sensor will also evaluate "muscle quality", the Omron shows a higher level of fat loss than the Tanita, and I believe an approach that the Omron is more accurate. Notice the large day seems to day variations; this is why I measure every day and look at the overall average. I use have a moving seven day average (the dotted lines) to evaluate the overall progressrelatively good scientific basis.<gallery widths=300px heights=300px class="center"><gallery>httpFile://fellrnrSkulpt.com/fellrnr/BFAjpg| The Skulpt deviceFile:Skulpt App (3).JPGpng| A screen shot from the Skulpt app</gallery>==BOD POD==
This is a chamber that works out your body volume accurately. Given the volume and weight you have the density, from which you can estimate body composition. This is the same principle used in underwater weighing, but far less unpleasant. The test costs about $25 at a gym, which makes it expensive to use regularly. There are two types of BOD POD, a recreational and a research model; The recreational model is used by many gyms and estimates lung function, whereas the research model actually measures lung volume. I found the BOD POD quick and easy, but the combination of the cost and the trip to a gym makes it tricky to use on a frequent basis. See http://www.bodpod.com/ for more details.
<gallery widths=300px heights=200px caption="Bodpod">
File:Bodpod open closed.jpg|The shows the Bodpod open and closed, which gives a sense of the size. If you're claustrophobic the bodpod may be oppressively small but for most people it should be fine.
File:Bodpod schematic.jpg|this schematic gives a sense of how bodpod works.
</gallery>
=DEXA=
''Main article: [[DEXA]]''
=Different tissues in the body absorb different frequencies of X-Rays at different levels. This technique (Deal-Energy X-Ray Absorpiometry) uses two frequencies of X-Rays and looks at the different absorption to work out body fat. This is the current 'gold standard' for clinical body fat measurement and provides a detailed breakdown of body fat and lean tissue in different areas of the body. [[File:DEXA page 1.jpg|none|thumb|x300px|This is the first page of a DEXA report that gives an overview of body fat composition.]]=Underwater Weighing==
This used to be the 'gold standard' of body fat measurement. The technique involves being weighed on dry ground and then again underwater having breathed out as much as possible. This gives a value of density, so it should have similar accuracy as the BOD POD, but is more expensive and unpleasant. I have not tried this technique.
==DEXA==Different tissues in the body absorb different frequencies of X-Rays at different levels. This technique (Deal-Energy X-Ray Absorpiometry) uses two frequencies of X-Rays and looks at the different absorption to work out body fat. This is the current 'gold standard' and I believe it will show the distribution of body fat as well as the level. I have not found anywhere locally that provides DEXA. [[File:DEXA female.jpg|none|thumb|400px|DEXA image.]] ==Alternatives to Measurement==
These approaches can give some hint about your body fat, but are no substitute for a real measurement.
===Waist to Hips Ratio===
This does not directly measure body fat, but is a crude measure of health. A ratio of 0.7 for women and 0.9 for men is correlated with good health. This is a crude measure, but can be useful for an initial evaluation.
===Body Mass Index===
This is a simple figure based on your height and weight, and gives no real indication of body fat. If you are overweight it can give a sense of your health risk, but overall it's quite useless.
===Mirror===
Looking at yourself in a mirror is a simple method that can give a sense of body fat. Obviously there is no numerical quantity to this test, but it's cheap and easy.
===Abdominal Muscle Definition===If your body fat is low enough, the definition in your abdominal [[Muscle|muscles ]] (six pack) can be used to monitor body fat changes. There is no specific body fat percentage for having a six-pack, but the common thought is that you need to be 12-8% for men and 18-14 for women.==References==[[Category:Beginners]][[Category:Training]]<references>[[Category:Nutrition]]<ref name="BIA1">Body composition changes assessed by bioelectrical impedance measurements http[[Category://www.ncbi.nlm.nih.gov/pubmed/2923071</ref>Weight]]<ref name="BIA2">Changes in fat-free mass during weight loss measured by bioelectrical impedance and by densitometry http[[Category://www.ncbi.nlm.nih.gov/pubmed/2912008</ref>Ketogenic]]</references>[[Category:Review]]
