Saturday 9 February 2013

How much protein do you need?



Protein
Amino acids from proteins are the building blocks for new tissue and repair. The International Olympic Committee (IOC) and the International Amateur Athletics Federation recommend 1.2-1.7g of protein per kg of body weight per day. However, this recommendation depends on the activity being performed. An endurance athlete will normally need less than a strength athlete. See table below (Bean, 2009).
Athlete Type
Daily protein per kg body weight (g)
Endurance (moderate to heavy training)
1.2-1.4
Strength/power
1.4-1.8
Fat-loss programme
1.6-2.0
Weight-gain programme
1.8-2.0

Taking me as an example. I weigh 65kg, so if I was endurance training I would need between 78-91g/day. If I was strength/power training I would need between 91-117g/day.
There is also the misconception that necking protein shakes throughout the day will increase your muscle mass. You will get bigger, but without muscle stimulation and the muscles needing rebuilding and repair, it will be your waistline.
During fat loss periods it’s good to increase protein levels to avoid the body breaking down muscle to fuel itself.
So that’s how much you need in a day, but you don’t just eat it all in one sitting, and how much can the body take in at one time and utilise anabolically (in muscle building) before it is used as fuel, stored as fat or excreted in urine.
A recent study of 6 athletes averaging 86kg were given 1.4g/kg/day, and put through 5 different leg training sessions. The weight was one that produced failure at 8-10 reps. The subjects were given 0, 5, 10, 20 or 40g of protein supplement after the sessions and injected with a traceable leucine, to see if it was incorporated into the muscle or burned as fuel.
The 0g dose was the worst for muscle synthesis and subsequent doses up to 20g produced better results for leucine incorporation. At 20g some of the leucine was diverted into the metabolic pathway and burned as fuel. The 40g dose had more diverted and protein synthesis was no better than at 20g.
In another study of male/female and young/elderly people with no weight training background, they were given a meat meal contain 30g of protein or 90g and examined over 5 hours after the meal. The higher protein content had no greater anabolic effect than the lower one.
In conclusion, if you are taking more than between 20-25g of protein in one sitting, you are probably wasting the difference.