Computing for Desirable Body Mass

        Body composition is the only non-performance measurement among the physical fitness components. Body composition is the proportion of fat-free mass to body fat. Fat-free mass is made of the body’s non-fat tissues which include bone, muscle, water, connective tissues, teeth, and organs. A small amount of fat is needed for the body to function properly. This is know as essential fat. In males, this is about 3% to 5% of total body weight. While in women, this is about 8% to 12% of total body weight. Other body fat is stored as adipose tissue, which is under skin and around the viscera.

       While most people still like to use weight as a guage for fitness, it is actually the percentage of body fat that most people should pay attention to.  Both the ACSM and the NSCA publish recommended norms for body fat percentage. Charts are presented below:

ACSM Body Composition Chart (1)

(image from http://healthypoints.info/)

NSCA Body Composition Chart (1)

        We can actually use these norms to compute ideal body weight or mass from the ideal body fat percentage. Mcadle, Katch and Katch (2) and Wilmore and Costill (3) present two approached to computing ideal body mass.

            The first step to both approaches is to get the fat free weight. Before doing that, you have to be able to determine the amount of body fat you have. The gold standard in getting body fat would be hydrostatic weighing (2, 3). However, due to the difficulty in finding equipment needed, the most practical and available would be getting the skinfolds using a body fat calliper. Most personal trainers and strength and conditioning coaches will be trained in using this method. There are several skinfold sites that are used to determine body fat. In addition, which sites to be tested will be the decision of the trainer. Information on the different sites is available elsewhere on the web. Once the skinfold sites have been measured, several formulas are available to derive the %BF. How to take skinfold measurements and computations is a different subject matter for the future.

            Another option is bioelectrical impedance analysis (BIA). Several machines are available on the market that measure body fat, weight, and resting/basal metabolic rate (RMR/BMR). Such machines are easy to use and are available in some gyms. If it’s available in your gym, have one of the trainers or staff take your body fat, weight and RMR. 

            Once the body composition, or relative body fat, is determined and compared to the charts above, one can now compute ideal body weight. Compute first for the fat-free mass (FFM), which is weight multiplied by the relative body fat.  For example, if a person has 28% body fat and weights 75 kgs, calculate first the fat weight:

                        Fat weight = Weight x relative body fat

                                          = 75 kgs x 28%

                                          = 21 kg

            Subtract the fat weight from the weight to get the fat free weight:

                        Fat Free Weight = Weight – Fat Weight

                                                   = 75kgs – 21kgs

                                                   = 54 kgs

            After computing for the FFM, we can compute for ideal body weight. Let’s start with Mcardle et al’s formula to compute ideal body weight (2):

                        Goal Body Weight = FFM / (1.00 – desired body fat)

            If, in the above example, the person is  a female aged 27, we can check the range of her ideal body fat using the chart used by the NSCA presented above. In this case, the ideal average body fat range is between 24% and 26%. We can compute the range of the desirable body mass:

            Goal Body Weight with 26% body fat = 54 kgs / (1.00 – 0.26)

                                                                         = 54 / .74

                                                                         = 72.97 kgs or 73 kgs

            Goal Body Weight with 24% body fat = 54 kgs / (1.00 – 0.24)

                                                                         = 54 kgs / 0.76

                                                                         = 71.05 kgs  or 71 kgs

            From the above calculations, using Mcardel, Katch and Katch’s formula, the ideal body weight for the a 27 year-old female weighing 75 kgs with 28% body fat, is between 71 kgs and 73 kgs.

            Another method, and similar in computation is the one presented by Wilmore and Costill (3). The computation for fat free weight is the same as above. Let’s use the same example given, 27-year-old female at 75 kgs with 28% body fat, the computed fat free weight is 54 kgs.

            Again, using the NSCA chart, we plug in the values for her age, 24% and 26% respectively.

            Thus, the computation for a goal body fat at 26%:

Goal BF% = 26%

            Goal fat –free mass = 100% - Goal BF%

                                             = 100 – 26

                                             = 74%                 

             Goal weight at 26% BF = Current fat-free weight / Goal fat-free weight

                                                  = 54 / 0.74

                                                  = 72.97 kgs or 73 kgs

            Weight loss goal at 26% BF = Current body weight – Goal body weight

                            = 75 kgs – 73 kgs

                            =  2 kgs

            Computing also for the lower BF%, we have the following computations:

            Goal BF% = 24%

            Goal fat-free mass = 100% - Goal BF%

                                           = 100 – 24

                                           = 76%

            Goal weight at 24% BF = Current fat-free weight / Goal fat-free weight

                                                   = 54 / 0.76

                                                   = 71.05 kgs or 71 kgs

            Weight loss goal at 24% BF = Current body weight – Goal body weight

                                                          = 75 kgs – 71 kgs

                                                          = 3.95 kgs or 4 kgs

            Both methods presented above produce the same figures as shown. Which method to use to compute desirable body weight will be up to the trainer.  Using the computations allows the trainer to present to their potential clients a more concrete goal in terms of achieving desirable body weight, along with the ideal percentage of body fat for their given age and gender.

Bibliography:

1. Earle, Roger W. and Thomas R. Baechle “NSCA Essentials of Personal Training” 2004
2. Mcardle, William D., Frank I. Katch, and Victor L. Katch “ Exercise Physiology: Nutrition, Energy, and Human Performance 7^th edition” 2010
3. Wilmore, Jack H. and David L. Costill “Physiology of Sport and Exercise 2^nd edition” 1999

Internet Bibliography:

      4. http://healthypoints.info/body-fat-norm-charts-acsm/acsm-body-fat-chartbody-fat-norm-charts-acsm-zgded/

The Deadlift

           The deadlift is one of the three main lifts in Powerlifting, along with the squat and bench press. It is the starting phase of the two Weightlifting lifts, the snatch and the clean and jerk. The name refers to the lifting of a weight with no momentum (often referred to as a dead weight) usually from the ground.
 
            The deadlift can be performed with the feet positioned in two ways: the shoulder width apart, or the conventional method, or with the feet wider apart such as in a sumo stance, hence the sumo deadlift. Another variation can also be performed with the legs straight, such as in the stiff leg deadlift. The conventional deadlift will be discussed in this article. In addition, the position of the hands can vary depending on the particular end goal of the exercise. There are three hand positions that may be of interest to strength training and conditioning coaches: alternated grip, clean grip, and the snatch grip.

Primary muscles involved (2, 3, 5)

            - Quardiceps muscle group
            - Gluteus maximus
            - Erector spinae

            - Forearm muscles (flexor digitorum)

Secondary muscles (2, 3, 5) 

            - Hamstrings muscle group

            - Trapezius

            - Rhomboids

            - Abdominals
                - Transversus
                - Rectus
                - Internal and External Obliques


 

(Image from fitosaur.us)

Execution and Performance (1, 2, 3, 4, 5):

1.   With a barbell on the floor, load the appropriate weight on to the bar

2.  Squat in front of the barbell with feet flat on the ground, between hip and shoulder width apart.

3. Grasp the barbell in either one of two ways, an alternated grip (one hand with a palms down grip, and the 

    other in a palms up grip), or a pronated grip (both hands in a palms down position).Grip width will vary 

    depending upon the particular deadlift exercise will be performed. With alternated grip, the width will be 

    maybe shoulder width apart or slightly wider. With the pronated grip, two widths are used. The clean grip is 

    slightly wider that shoulder width apart. This is in preparation for the clean exercise. The snatch grip is a 

    wide grip used in preparation for performing the snatch lift.

4.  After taking the chosen grip position, position the bar about an inch in front of the shins and over the balls of the feet.

5.  With the back flat, head level horizontally, and eyes focused forward. Lift the bar off the floor by extending the knees 
     and hips. In other words, begin to stand up while lifting the weight off the floor. 

6.  Maintain the flat back position all the way up to the top most position. Pause at the top of the movement. 

7.  Return the barbell to the floor by reversing the movement. Maintain the flat back and eyes forward during the 
     lowering phase. The return to the starting position should be controlled and smooth. 

8.  Repeat for the desired number of repetitions. 

 

Deadlift (pronated grip) bottom position

Deadlift (pronated grip) top position

 (Images from www.bodybuilding.com)

Images below show the clean grip and snatch grip deadlift. Note the width of the grip.

Clean Grip Deadlift bottom position

Clean Grip Deadlift mid-lift phase

Clean Grip Deadlift top position

Snatch Grip Deadlift bottom position

Snatch Grip Deadlift top position

  (Images from www.bodybuilding.com)

Sport Uses (3):

 

            The main joint actions of the deadlift are knee and hip extension during the upward phase of the movement. Static contraction of the core muscles, trapezius, rhomboids and finger flexors all help in controlling the body and the weight being lifted. The core muscles help in stabilizing the trunk and keeping the spine erect. The traps and rhomboids stabilize the shoulders. The finger flexors help maintain a strong grip on the bar.

            Knee and hip extension is important in pulling type actions such as when lifting a bar off the floor. A powerful pull is important in events such Weightlifting for the clean and jerk and the snatch. The knee and hip extensions are also important in sports that require jumping, running and sprinting. A strong and powerful extension of the knee and hips in these movements helps deliver more force to the ground enabling a higher jump, faster runs and sprints. In sprinting and running, when the foot gets into contact with the ground, the hip extends and propels the body forward, the knee extends and gets the body airborne. Sports such as the high jump, basketball, volleyball, soccer, football, or any sport that has a high amount of running and jumping can benefit from deadlift.

Bibliography:

1.     Baechle, Thomas R. and Roger W. Earle “Essentials of Strength Training and Conditioning 3^rd Edition” 2008 

2.    Delavier, Frederic “Strength Training Anatomy” 2001

3.    Muscle and Fitness “Training Notebook” 2002

4.    NSCA Certification Commission “Exercise Technique Checklist Manual” 2004 

5.    Sprague, Ken “The Gold’s Gym Book of Strength Training for Athletes” 1979

Images:

1.      fitosaur.us

2.     www.bodybuilding.com