It’s common for athletes to take in some carbohydrate after a workout. The desire for sugar is typically high at that time. This is beneficial in that it is known to increase the glycogen stores in the muscles which have been depleted by exercise. Decades of research has shown this to be effective for hastening recovery. And the sooner you recover the sooner you can do another quality workout thus shortening the time to achieve a high level of fitness.
There has been much less research done on protein after exercise, but there is a growing body of work which shows surprising levels of improvement by taking in some protein immediately afterwards. Here are some studies from the last few years all of which support this notion. There is a bit of latitude in how much protein you should take in along with your carb as you can see from study summaries below. The range in these studies was about 26 to 400 calories from protein after a workout. That’s a huge difference. But as you will see, these studies did not examine the same benefits, although there is overlap. More research is needed to narrow this down somewhat. In the mean time you are on your own to decide how much.
There’s little doubt that taking in protein along with carbohydrate immediately following a session, especially a hard workout, is beneficial. I suggest to the athletes I coach that they do this in the first 30 minutes after a hard workout. I leave how much carb and protein up to how they are feeling and what seems appropriate as it’s unlikely that what is needed will always be the same regardless of the many variables (workout duration and intensity, pre-workout and during-workout intakes, weather conditions, and more). The sensations of appetite and thirst should be the driving factors. (Click on the citation to read the abstract.)
Six cyclists had a 29% greater glycogen resynthesis using a carb+protein recovery drink following exercise vs. a carb recovery drink only. The carb-protein ratio was 2:1 with 4.8 calories per kilogram of body weight. The carb was maltodextrin and the protein was whey.
10 trained cyclists rode for 90 minutes at 77% of their VO2max on 2 occasions. Immediately after exercise and 30 minutes after they drank either carb (25g/100 cal) or carb+protein (25g + 10g/140 cal total). Muscle protein synthesis was 35% greater with carb+protein.
4 matched groups of 8 men each did a muscle-damaging workout. They drank a carb+protein drink (milk) before exercise, immediately after, or 24 hours after. Delayed onset of muscle soreness, power and strength measure 24, 48 and 72 hours after exercise found that the best times to consume the carb+protein drink were immediately after and 24 hours after.
9 active men ran down a -10 degree slope for 30 minutes at 75% of max heart rate on 2 occasions. Immediately afterwards they took in 100g (400 cal) of protein or a placebo drink. By 48 hours after exercise delayed onset of muscle soreness (DOMS) was high and quad strength was decreased by 10% in the when using a placebo drink. There was no DOMS or reduction in quad strength with the protein drink as compared with a pre-run test.
10 cyclists each did 3 trials of 1.5 hours at 70% of VO2max followed immediately by 10 minutes of intervals. They then rested for 4 hours and did a 40km time trial. During the rest break they drank either chocolate milk (carb+protein), a carb drink (carb) or a placebo (pla) immediately after exercise stopped and 2 hours later. Time trials were faster with carb+protein (8% faster than carb and 9% faster than pla).
8 runners drank an 8% carb + 2% protein drink and a 10% carb drink on 2 separate occasions between runs to failure followed by a 5km time trial. There was no difference in performances, but there was less soreness after the carb+protein drink.
Supplementation with 6.6g per day of protein immediately following exercise for 1 month increased blood oxygen-carrying capacity and decreased levels of muscle damage.
20g (80 cal) of protein ingested immediately after exercise improved muscle protein synthesis (muscle repair) better than taking it in when not preceded by exercise. This worked equally well in both young and elderly men.

Joe,
Do you think the same physiological phenomenon described above responsible for reducing recovery time (muscle repair, etc.) is at play when protein is taken during extended 3 hr+ efforts - or is that apples and oranges?
Posted by: Brett | 01/12/2012 at 12:53 PM
Brett--See my previous post on protein during exercise. Search "protein".
Posted by: Joe Friel | 01/12/2012 at 01:22 PM
Joe,
My recovery drink is generally a large glass of skimmed milk. I was under the impression that after excercise your muscle will absorb more protien than normal because, during workout, fibers are torn and streched slightly so muscles take on protien as a repair mechanism? This, in turn, helps to build muscle. Is this the right idea?
Posted by: David Reilly | 01/13/2012 at 05:08 AM
Joe,
Were the test subjects in these studies performing their bouts of exercise in a fasted state? Would fasting affect the outcome of the studies? For instance, if I am eating adequate protein/calories and exercising in the evenings, does the timing really matter?
Posted by: Kent | 01/13/2012 at 09:48 AM
(WebMD) During a 2004 Summer Olympics awash in controversies over steroids and supplements, one sportswriter wryly noticed that top American swimmer Michael Phelps was playing it safe -- he preferred to drink Carnation Instant Breakfast between races.
Now it appears that the six-time gold medalist may have been onto something. A new study shows that plain old chocolate milk may be as good -- or better -- than sports drinks like Gatorade at helping athletes recover from strenuous exercise.
Posted by: Jules | 01/13/2012 at 10:05 AM
Sorry Joe here is the link
http://www.cbsnews.com/stories/2006/02/24/health/webmd/main1342839.shtml
Posted by: Jules | 01/13/2012 at 10:14 AM
Kent--Yes, protein timing and chronic diet both matter.
Posted by: Joe Friel | 01/13/2012 at 02:41 PM
David Reilly - Yes, appears to be correct.
Posted by: Joe Friel | 01/13/2012 at 02:42 PM
david doherty - It might be. Especially given your anticipated time. That's about the biggest variable for determining this.
Posted by: Joe Friel | 01/13/2012 at 02:43 PM
How come races still don't provide a lot of protein alternatives after races? Sure you might occasionally come across some peanut butter, or maybe even some yogurt but nothing with a ton of protein in it.
In recent years I have always packed some Whey in a container but usually it is hour or so at least before I remember to take it down.
Posted by: Thomas Gerlach Professional Triathlete | 01/13/2012 at 09:06 PM
Joe, anecdotally I have to 100% agree. Being a veggie perhaps my protein should have been more carefully monitored. I used to get pains in my legs which I bravely attributed to "trying really hard". I now have whey immediately after (and sometimes during) my sessions and I have noticed a VERY marked lowering of leg pain. I didn't find milk anywhere near as effective.
Posted by: The5krunner | 01/25/2012 at 03:11 PM
Joe, how about chocolate chip cookies post-workout? J/k, seriously, I saw that as one of the snacks post-race in Austin last year. I'm curious about what type of protein is best. Does it matter if it is in the form of a powder vs. whole food? Cheers.
Posted by: Kevin | 04/10/2012 at 09:01 AM
Kevin--You need sugar after a race to restock glycogen stores. I don't see any problem with eating a cookie as one source.
Posted by: Joe Friel | 04/14/2012 at 06:53 AM
Interesting article. I've always heard people recommend protein after a workout, but its hard to come across a consistent argument as to why or how much. Thanks!
Posted by: Build Muscle | 04/20/2012 at 01:14 PM
When I was a younger man in the SADF ( South african Defence force) We used to train really reallyyyyyyyyyyy HARD all day in the hot african sun. Guess what I used. Bar one x 4 like a mars bar and a can of salted sardines! Could not stomach that today but at the time it gave me energy to overcome the hardest day fighting terrorists up some or other ravine... Today as a long didtance swimmer I am using whey concentrate, glucose and maltodextrin mixed up in a bottle every half hour. Great blog I enjoyed the read.
Posted by: max | 01/03/2013 at 12:30 PM