The Core Diet Blog

Anthropometrics, the measurement of the human individual for the purposes of understanding human physical variation, can be excellent tools for athletes to help achieve a sport specific body composition. Individual sports may have optimal metrics so that strength is not a limiter or present in excess and either ultimately hamper the athletes' performance, not enhance it.

Body fat percentage and Body Mass Index (BMI) used in conjunction combine to produce an effective sport specific metric, the sum being more insightful than the two parts by themselves. Based on age and gender, we can determine appropriate parameters for optimal body fat percent and then by sport specific categorizations, optimal BMI. However, the road to a goal weight for an event that is 8 months away is not a straight one.

For triathlon, the training may begin in January at 10 pounds over goal weight for an Ironman in June. There are several risks for the athlete arriving in June under or over goal that translate to compromised training and/or race day performance. Illness, injury, suboptimal training, and early fatigue are common issues that may be decreased significantly by fueling properly from beginning to end, and maintaining recommended "healthy" weights throughout the training and racing season.

Training for most athletes begins with strength work to maximize muscle building and durability. Here, additional calories and/or protein are prudent to support the necessary anabolic environment for muscle growth. Commonly, athletes are hurried to pull off extra pounds from the off season, missing a vital opportunity to support muscle growth. As training becomes more sport specific, and volume begins to grow in duration and intensity, the increase of carbohydrates is necessary to provide protein sparing calories for increased activity. Typically, this is easily achieved, and more often, over achieved by athletes over consuming carbohydrates. Once carbohydrate-based workout fuels and recovery aids are tallied with the amount of wholesome food carbohydrates, athletes may find they have overshot their recommended intakes, and have subsequently failed to meet their recommended weight for a particular phase of the "A Race" buildup. Conversely, as training volume increases and the athlete fails to increase caloric intake, weight loss becomes evident leaving the athlete underweight without proper fat stores and lean body mass to realize full potential during training. Compromised training translates to compromised performance.

The first step in determining how to proceed to avoid common pitfalls, is to determine your current body fat percent and BMI, then set personal goal BMI and body fat for your sport. Choose your A-race, making note of any important key races and training sessions along the way to use as mini goal benchmarks. Approximately 4-6 weeks out from your "A Race", evaluate yourself for the final push toward optimal body composition. Ideally, arrive at your final goal 3 days pre-race, or a bit more lenient window of no more than 14 days out.

Choosing your A race immediately establishes your time frame, your training schedule and your caloric requirements for each phase of training. As stated before, the muscle building phase requires an increase of protein, and of overall calories. Protein intake for those who are low BMI athletes may be as high as one gram per pound body weight per day, with a 200 calorie surplus. Body weight may begin to climb, as muscle weighs more than fat. The better metric to monitor for this phase is body fat percentage. If your weight increases, but your body fat is maintained or decreases, you are likely building muscle.

Moving in to beginning sport specific training, overall caloric requirements are typically a small amount higher than in the strength building phase. The muscle needs to be maintained with appropriate amounts of protein, but the overall expenditure of calories can take a mild dip as we eliminate the surplus. This transition may be tricky as athletes perceive this to now be "real" training. However, managing macronutrients the first few weeks can be misunderstood and implemented improperly. Athletes should maintain protein, and the slight increase in carbohydrates is almost entirely fulfilled with training fuel and recovery aids. Unwanted body fat can easily accumulate if calories are not carefully controlled. The attitude of "I'm training for an Ironman so can eat anything", typically results in weight gain because exercise related expenditures are typically half fulfilled during a good fueling program.

As each period of training continues, the overall caloric intake must increase to match the increasing training volume. Close attention is required here during periodization planning of both the training and nutrition programs. Typically, one week out of every three to five will be of lower duration, frequency and/or intensity with the following period beginning slightly more strenuous than the previous, building to some end point of a slightly higher workload. Fluctuations in training volumes should be met with appropriate caloric intake, usually achieved by increasing carbohydrate calories for from workout fueling.

Approximately 4-6 weeks out from the A race, athletes should assess current body composition as compared to the goals and make the necessary adjustments to hit goal. Underweight athletes with a proper body fat percentage should continue to add carbohydrate based calories until their training taper begins. Overweight athletes will need to carefully reduce the number of calories they take in without jeopardizing training fuel and recovery calories. If body fat numbers are slightly above goal, an increase in protein and a decrease in fat may prove beneficial to maintain muscle mass while reducing overall body weight from body fat.

During the taper, athletes must again be wary of weight gain and diligently match the caloric requirements to the training volume. The reduction should be taken from carbohydrates as less are required as the training volume declines. As race day approaches, athletes should be within 1-2 pounds of goal weight, and body fat met approximately 3-14 days before race day. These goals are meant to be met for optimal performance, and may not be comfortable or well regulated by the body for extended periods of time. Therefore, the closer to race that the goals are achieved, the more benefit and less risk of adverse outcome there is.

Throughout the season, athletes should not only mind the metrics, calories and macronutrients, but must also be aware of micronutrients. High volume training creates high volume demands throughout the body including energy production, muscle and system recovery, muscle repair, anti-oxidation and anti-inflammation. Many vitamins and minerals are essential for these processes to occur, and every athlete should be actively supplying the body with these vital micronutrients on a daily basis thru lean meats, fruits, veggies, nuts, and seeds.

Body composition is without doubt a critical factor for athletes, and is clearly defined by the sport in which the athlete participates. Each sport has an optimal body composition for optimal performance, but getting there is sometimes not as well defined. Nutrition needs to be planned as a part of the training, so that both may enhance the other. Leaving nutrition out of the equation certainly compromises training and can have lasting effects on one session or the whole season. Make sure to set your sport specific goals while monitoring and matching your metrics to your appropriate, desired body composition to achieve your best performance.

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Excellent article...specifically periodization walk through. Question: In addtion to BMI and Body fat% does muscle mass and/or size play a factor in triathlon performance?
by Alex Umansky -13 years ago- 03/03/2011, 13:44
Alex: Absolutely! This is specificaly why we use a lean adjusted BMI to evaluate muscle mass. Check out this writing which explains the approach: -Jesse
by Jesse Kropelnicki -13 years ago- 03/17/2011, 22:00

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