just another gosling
Join Date: Feb 2007
Location: Everett, WA
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
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Some more protein information and thoughts:
Dr. Misner of Hammer Nutrition claims that an athlete should consume no more than 40g of protein in a 3 hour window. He claims that at more than 40g at a meal, some protein will be diverted to fatty adipose tissues.
Dr. Misner also believes that an athlete should consume no more than 1.4g-1.7g protein per kilogram of body weight per day. The upper limit to be appropriate to periods of greatest training volume. And remembering that Hammer caters to Ironman athletes, greatest training volume would be in excess of 20 hrs./week.
On the other hand . . .
We can do some interesting calculations. It's known that during an event or training lasting more than 3 hours, athletes get between 5% and 15% of calories burned from protein. Let's say 10%, just to make it easy. A 400k brevet might take an experienced rider 18 hours to complete. For the last 400k I did, my Polar estimated 10,000 calories burned, or about 555/hr., including rest stops. Which seems reasonable. One can't go very hard for such a long time. So 10% of 555 is 55 calories of protein per hour burned or about 14g. We attempt to get as much of that protein from our food during an event as is digestively possible. Most people attempt to consume about 250 calories/hour during an event. Acclerade and Ensure Plus are about 4:1 carb to protein. If one consumed only these beverages, as many LD racers do, one would get 62.5 calories/hr, or about 16g. This comports very well with a 10% burn rate. Hammer Nutrition products which contain protein are about 7:1 carb to protein. So this rate of protein intake comports more closely with a 5% burn rate.
In either case, over an 18 hour brevet, the rider will ingest between 9g and 16g protein per hour or between 162g and 288g total protein. For a 70 kilo rider, this is between 2.3g and 4g per kilogram, and this doesn't even count the pre and post ride meals.
What I take from these conflicting quantities is that Dr. Misner's 1.4g-1.7g/kilogram/day protein allotment does not take into account the protein consumed during the event or training, when the athlete is simply burning it off, rather than using it for repair and other metabolic services.