Training & Nutrition - protein

How much protein the human can consume every time and not become wasted?

Do you want to know max or min amounts? The minimum depends mostly on 2 things. How much mass you need to feed and how much exercise you are doing.
Find out your base calorie consumption, then add for the calories burned by the things you do during the day.

It depends on who you talk to, but generally 2g/kg is about the upper limit for useful daily protein intake. I've seen that pushed as high as 4g/kg, but diminishing returns are to be expected.

I think he might be referring to how much protein can consume at one time (such as a single meal). I'm also curious. I've heard 20 grams is the maximum your body can process, anything more isn't useful. Any truth to this?

Thats what I have heard too, depending on how much carbs your body has at the time to use its around 20-25g per meal. How true is it? I don't know, but the people that told me that info were fitness freaks and I'm fairly sure knew what they were talking about.

40g max

in a day? I think I remember hearing an average of 1 gram per pound of body weight. less if you are inactive or small, and more if you are a body builder

forget any benefit or lack of benefit...
way too much = kidney damage.

pro tip: kidneys do not heal, you can only prevent more damage.

forget any benefit or lack of benefit...
way too much = kidney damage.

pro tip: kidneys do not heal, you can only prevent more damage.I've been using 15g whey protein before meals and after a ride for many years, though I will take 24g after a multi-hour hard ride. I'm still a perfect human specimen, so that's not disastrously too much. Nor is it too little. I could probably get by with less, but the only way to see is to short yourself on it and assess the damage. I don't have time for that. I weigh about 158.

For most of us who do not solely eat packaged meals, our daily protein intake is unknown. I know that there are some OCDs on here who analyze every food of every meal and log its complete nutritional breakdown, but I don't have time for that, either. Most of us are just guessing. Certainly, the more you ride, the more protein you need, and conversely. Endurance riders need more than bodybuilders, by quite a bit.

I don't believe the answer to the OP's question is known. My belief is that it's better to spread it out over the day, but also that a bolus after a long ride is good.

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.

I was with you but then my eyes glazed over. What we can all take from this is that we need to stay diligent with out research and be conscientious about our nutrition.

I like to think that maintaining a steady spply of protein is important for active people like bikes. But of course timing nutrition is almost more important.

Bill Misner's number seems to be somewhat consistent with what body builders consume. They usually figure 1-1.5 g/lb. For a 200 lb body builder that's 300 g tops for a 150 lb road rider that's 225 g. 40 g every three hours comes out to 240 g/day. So roughly the same.