The recommended dosage of HMB is three grams per day for average-size individuals. If you want to "customize" your dosage, research has shown that 38 mg per kg or 17 mg per pound of body weight each day is optimal (see chart for simplified dosage scale, Strength and Muscle Building: 2000: Gallagher). You should divide the daily dosage into two or three equal servings and take these servings spread out over the day.
In regards to HMB timing near or around a training session, we recommend that you take one of your daily servings of HMB an hour before exercise to help reduce muscle damage. If you are unable to take HMB prior to exercise, then take a dose immediately after your muscle-building workout or training session. For example, if you workout in the evening, take one serving in the morning and one an hour before your evening workout. If you workout in the morning, take your first serving right before or after your morning workout and a second serving at night.
For more information on how to improve training performance with HMB: