Archive for October 12th, 2009

Tuesday, October 13, 2009

Monday, October 12th, 2009

Workout of the Day:
Push Jerk
3-2-1-1-1
and then,
Teams of two will complete three rounds each of:
7 x One-Arm Dumbbell Snatch (each arm)
14 x Lateral Jumps (24″/18″ hurdle)
21 x Knees to Elbows
While one partner works through the round, the other must hold two dumbbells fully extended overhead. If the dumbbells are dropped from overhead, both partners must perform 3 burpees before resuming the remainder of their round. If you don’t have a partner, rest with dumbbells extended overhead for as long as it took you to complete the round – performing 3 burpees every time you drop the dumbbells.
Glycemic Graph

Low-Glycemic – Part One
Written by Calvin Sun

In recent years, “low-glycemic” has been a phrase used with increasing frequency in advertising and advocating health foods. Glycemic index (GI) is simply a measure of how a food affects your blood sugar levels. High-GI foods break down very quickly resulting in a rapid release of glucose into the bloodstream. On the other hand, low-GI foods break down more slowly resulting in a much more gradual release of glucose. Typically, low-GI foods are touted as the best way to control blood sugar and insulin levels thereby assisting in weight loss. But just because a food is rated as low-glycemic does not mean it is good for you. While most fruits and vegetables fall into the low-GI category, a few examples of foods that are “low-GI” but not necessarily good for you include ice cream, some pastas, and many candy bars.

Does this mean pasta and candy bars are OK to eat? Absolutely not. The GI of a food is affected by factors such as preparation method, your own biochemical composition, protein and fat content, and not to mention the amount consumed. Also, keep in mind that GI is determined by comparing it against a reference food of the same quantity.

“The GI value of a food is determined by feeding 10 or more healthy people a portion of the food containing 50 grams of digestible (available) carbohydrate and then measuring the effect on their blood glucose levels over the next two hours. For each person, the area under their two-hour blood glucose response (glucose AUC) for this food is then measured. On another occasion, the same 10 people consume an equal-carbohydrate portion of glucose sugar (the reference food) and their two-hour blood glucose response is also measured. A GI value for the test food is then calculated for each person by dividing their glucose AUC for the test food by their glucose AUC for the reference food. The final GI value for the test food is the average GI value for the 10 people.” – GlycemicIndex.com

An interesting point to note here, white bread is often used as the reference food as it can illicit a GI response even higher than pure sugar. One problem with this testing methodology is that 50 grams of carbohydrate is not always a realistic serving size. You’ll easily eat twice that amount if you are eating ice cream or some sort of starchy food such as bread, potatoes or pasta. Conversely, you’ll eat a fraction of that amount of carbohydrates if you are eating fresh fruits or vegetables. For example, watermelon has a high-GI rating of 72, yet your average 1 cup serving of watermelon has less then 10 grams of carbohydrates.

Glycemic Load (GL) values are good way to deal with these differences in actual carbohydrates consumed. GL takes into account both the GI and the total amount of carbohydrates in a standard serving. The GL of a food is calculated by the following formula: GL = GI/100 x Carbs per serving. Using this formula on our watermelon data (72/100 x 10g), we find that the GL of watermelon is only 7.2 (a GL of 10 or below is considered low and a GL of 20 or above is considered high). Compare that to a Snickers Bar which has a low-GI rating of 55 but 64 grams of carbohydrates in a serving (55/100 x 64g). That’s a GL value of 35!

Despite GL values taking into account the amount of carbohydrates in an average serving, the rating system is not without fault. In part 2, we’ll discuss the limitations of both Glycemic Index and Glycemic Load.