Well, they are a good source of slow carbohydrates and intestine healthy fats. But alas, grasshopper, that is not the only reason.
You see avena satia contains this stuff called avenocosides, which are a type of plant saponin similar to the furostanolic saponins in Tribulus.
Like the saponins in tribulus these saponins increase the amount of luteinizing hormone (LH) released from the pituitary gland, which influences the testicles to produce more testosterone.
In addition, these avenocosides free up testosterone from its carrier protein, sex-hormone-binding globulin (SHBG). Free testosterone is the type that is available to enter muscle cells resulting in growth and boost strength gains.
The recommended dosage is 100-300mg of a 10:1 Avena sativa extract two or three times a day, with one dose 30-60 minutes before workouts.