Lightweights
I alluded a few posts ago to Lance Armstrong's recommendation that his rival Jan Ullrich begin the Tour a few pounds lighter. What follows is a noted triathlon coach's thoughts on body weight, how best to reduce it, and athletic performance:

Around the time of the Tour de France there are often questions about how an athlete should go about losing weight in order to climb better. There’s little doubt that being lighter means climbing faster. Pro cyclists who contend for the yellow jersey, the polka dot jersey or who need to support their team leader in the Alps and Pyrenees try to be lean by the time the terrain turns upward. The best climbers are generally less than 2 pounds of body weight for every inch of height (divide your weight in pounds by your height in inches to find this number). It’s rare to find a rider in the pro peloton at 2.5 pounds per inch or greater. A lot of them who are not climbing specialists are around 2.1 to 2.2. The latest average I have for the TdF field shows an average of 2.151 pounds per inch (thanks to Gregory Byerline for providing that data).

Every pound of excess fat shaved from your body saves you about 3 watts in a climb. In running it is something like 2 seconds per mile per excess pound in a race. For most endurance athletes, a 1-point shift in weight-to-height ratio means about 5 percent loss of weight—around a 7- to 9-pound loss of love handles. That can be done safely over a two-month period if there is a big A-race with lots of climbing or the need to run faster on the calendar a couple of months from now.

How is it best for an athlete to lose weight? Unfortunately, there have been few studies of serious athletes that looked at this question.

One group of researchers, however, has examined the issue in an interesting way. They compared eating less to exercising more to see which was more effective in dropping excess body fat.

They had six endurance-trained men create a 1,000-calorie-per-day deficit for seven days by either exercising more while maintaining their caloric intake, or by eating less while keeping exercise the same. With 1,000 calories of increased exercise daily—comparable to running an additional 8 miles or so each day—the men averaged 1.67 pounds of weight loss in a week. The subjects eating 1,000 fewer calories each day lost 4.75 pounds on average for the week.

So, according to this study, the old adage that “a calorie is a calorie” doesn’t hold true. At least in the short term, restricting food intake appears to have a greater return on the scales than does increasing training workload.

Notice that I said “on the scales.” The reduced-food-intake group in this study unfortunately lost a greater percentage of muscle mass than did the increased-exercise group. That is an ineffective way to lose weight. If the scales show you’re lighter, but you have less muscle to create power, the trade-off is not a good one.

How can you reduce calories yet maintain muscle mass? Unfortunately, that question hasn’t been answered for athletes, but it has been for sedentary women. Perhaps the conclusions are still applicable to athletes.

In 1994, Italian researchers had 25 women eat only 800 calories a day for 21 days. Ten ate a relatively high-protein and low-carbohydrate diet. Fifteen ate a low-protein and high-carbohydrate diet. Both were restricted to 20 percent of calories from fat. The two groups lost similar amounts of weight, but there was a significantly greater loss of muscle on the high-carbohydrate, low-protein diet. It appears that when calories are reduced to lose weight, which is more effective than increasing training workload, the protein content of the diet must be kept at near normal levels. This, of course, assumes that you’re eating adequate protein before starting the diet, which many athletes aren’t. When training hard, a quality source of protein should be included in every meal, especially when trying to lose weight.
--Joe Friel, Ultrafit.com