Fitness Over Forty, a weekly series of video presentations targeting the increasing "over forty" population in East Texas, addresses health and fitness issues that are specific to men and women ages 25 to 54 and older... more »

Dr. David Di PaoloDr. David Di Paolo, radiologist at The University of Texas Health Science Center at Tyler and nationally certified fitness trainer, hosts the series featuring UT Health Science Center medical professionals who inform viewers about the benefits of a healthy diet and active lifestyle... more »

Optimal Time for Supplementation

Tuesday, August 7, 2007

Additional Resources

Optimal Time for Supplementation - Tuesday, August 7, 2007Many individuals - not just bodybuilders or athletes - consume protein supplements. Supplements have been used as meal replacement drinks in those desiring weight loss. They are also consumed in addition to a regular diet by many people who engage in strength training exercise.

Protein supplements are often ingested as drinks, although they may be in solid form, such as bars. These supplements typically contain a combination of protein and carbohydrate, as well as a variable amount of fat. Other nutrients, such as creatine monohydrate, may be added, as well as vitamins and minerals. Previous studies have shown that supplementation with creatine monohydrate can promote greater gains in lean muscle mass and strength in those engaging in a program of resistance training compared with those who do not ingest this substance but perform resistance training alone. Other investigations have shown that supplementation with protein and amino acids can assist in promoting protein synthesis and a positive nitrogen balance in those who participate in a program of strength training.

In a recent study published in the official journal of the American College of Sports Medicine, Medicine & Science in Sports & Exercise, investigators sought to determine whether the timing of protein supplement intake made a difference. Specifically, they wanted to evaluate whether taking such a supplement just before and just after a workout was more beneficial than taking a supplement at other times during the day, remote from the time of the workout session. This study enlisted males who were accustomed to strength training. The investigation was conducted over a 10-week period. The supplement contained protein (from whey isolate), carbohydrate, glucose, a very small amount of fat, and creatine monohydrate. Per 100 gm of supplement, 40 grams of protein and 43 grams of carbohydrate were present; 100 gm of the supplement contained 7 gm of creatine monohydrate and less than 0.5 gm of fat. The participants ingested 1 gm of the supplement per kilogram of body weight twice daily. One group took the supplement drink in the morning and evening; the other group took the drink and just before and just after the workout. The participants knew when they were taking the supplement. The researchers, on the other hand, were blinded as to when the subjects were consuming the drinks. Body composition was analyzed with a dual energy x-ray absorptiometer (DEXA machine), and strength assessment was done, evaluating the strength in the bench press, dead lift, and squat. Also, muscle biopsies of the thighs were obtained for all participants.

After 10 weeks of training, supplementation before and after each workout was associated with significantly greater improvement in muscle strength compared with consuming the same supplement outside of the pre and post-workout time frames (i.e., in the morning and evening). Also, there was a more beneficial change in body composition over the 10 week period in those who consumed the supplement just before and just after the workout as compared with those who ingested the supplement in the morning and in the evening; there was a greater increase in lean muscle mass and reduction in body fat in the group taking the supplement just before and just after the workout. It was also found that the pre-post supplementation group demonstrated higher muscle glycogen compared with the morning-evening supplementation group. In addition, the subjects that had the supplement just before and after the workout demonstrated significantly higher muscle creatine concentration than those in the other group.

In summary, if you engage in strength training and consume a protein supplement, it does appear that there is an optimal window of time to take the supplement. In this study, taking half of the supplement before the workout and half of the supplement after the workout was significantly better than taking the supplement in the morning and evening, at times remote from the exercise session. This study evaluated the benefit of supplementation in healthy males who had been engaged in a regular routine of bodybuilding. The researchers speculate that the findings in this study may have important implications for populations that require improvements in strength and body composition but have a reduced capacity for exercise, such as frail elderly persons, cardiac rehabilitation patients, or those who have chronic conditions that can compromise health, such as cancer or HIV infection.

  • Cribb PJ and A Hayes. Effects of Supplement Timing and Resistance Exercise on Skeletal Muscle Hypertrophy. Med Sci Sports Exerc, Vol. 38 No 11, PP. 1918-1925, 2006
For more information:

NOTICE: Protected health information is subject to electronic disclosure.