Several studies have examined whether combining bodybuilding supplements offers more benefits than using a single supplement. I’ve previously reported in this space that combining whey and creatine, especially when you take them close to training time, significantly boosts gains in muscle size and strength for most bodybuilders. A new study featured 52 men and 17 women, average age 22, who were randomly assigned to one of three groups and received one of the following. They received:
1) six grams a day of conjugated linoleic acid, nine grams a day of creatine monohydrate and 36 grams a day of whey protein.
2) the same amount of creatine and protein as group 1, with the substitution of a placebo oil for CLA.
3) the same amount of whey protein and the placebo oil instead of CLA.
The study had a double-blind design, meaning that neither the study participants nor the researchers knew who was taking what.
Six days a week the subjects engaged in high-volume strength training for five weeks, averaging four to five sets per exercise, six to 12 reps per set. The authors conducted a range of tests before and after training, including body composition, ultrasound—for muscle thickness—one-rep-maximum lifts in the bench press and leg press, and urinary markers of bone resorption, muscle protein breakdown, oxidative stress and kidney function.
The supplements chosen for the study have an impressive record of effectiveness for bodybuilding purposes. Much research points to an anabolic effect when creatine is combined with resistance training. Conjugated linoleic acid is a beneficial form of the notorious transfat, consisting of a group of 18-carbon polyunsaturated fatty acid isomers derived from linoleic acid, an essential fatty acid. Unlike linoleic acid, however, CLA is not considered essential in human nutrition. Many studies show that when animals are given CLA, they often gain lean mass and lose a significant amount of bodyfat. The fat loss is often attributed to upgraded fat oxidation through stimulation of thermogenic uncoupling proteins in the cellular mitochondria.
The data on human use of CLA have been largely equivocal. On the other hand, some human research has found benefits from combining strength training with CLA. A 2006 study, for example, found that human subjects who took CLA supplements for seven weeks experienced significantly more muscle gain and fat loss than a group that didn’t take it but trained using similar routines. Note that the animal studies always involve much higher doses of CLA than the human studies do.
Like creatine, whey protein appears to foster gains in muscle size and strength when combined with weight training. Whey is rapidly digested, which brings on muscle protein synthesis after training. It’s also rich in the amino acids that are the most potent in muscle protein synthesis, branched-chain amino acids, leucine in particular.
Given the demonstrated effectiveness of CLA, whey and creatine, the authors postulated that combining all three would be more effective than taking any of the supplements alone. They were also watching for potential health risks of using the supplements, such as increased oxidative stress, negative effects on bone mass and undesirable changes in kidney function. Both increased protein intake and creatine use have been implicated in adverse changes in kidney function, although that’s more speculation than fact, as measured by studies on the subject. Some studies suggest that CLA may cause oxidative stress. Indeed, some human studies have found paradoxical side effects from CLA use, such as increased insulin resistance in men who have a lot of abdominal fat—itself a primary cause of insulin resistance. On the other hand, those studies usually involve sedentary, nonexercising subjects.
This study found that those taking all three supplements experienced more gains in bench press and leg press strength, along with lean tissue mass gains, than the other groups combined. The groups taking creatine gained more lean mass than those who took only whey protein. Previous research showed that CLA produced greater gains in bench press strength in men but no effect on leg press strength and also no effect in women. While the precise mechanism of how CLA can influence muscle gains isn’t clearly established, one plausible hypothesis is that it reduces the inflammatory cytokines that produce muscle catabolism, such as tissue necrosis factor-A, a signaling agent in loss of muscle. It’s a primary suspect in the loss of muscle with age, as its levels increase in the elderly. CLA didn’t produce any changes in fat mass in this study, although previous studies show that it’s more effective for that in those who have more initial bodyfat. It doesn’t do much for people who are already lean.
Both CLA and creatine have been found to provide anticatabolic effects in muscle, and the combination of the two used in this study confirmed that. No increased oxidative stress or apparent negative effects on kidney function occurred in this study. The authors suggest that the combination of creatine, CLA and whey protein spurs gains in lean mass and strength for those engaged in resistance exercise and bodybuilding.
Cornish, S.M., et al. (2009). Conjugated linoleic acid combined with creatine monohydrate and whey protein supplementation during strength training. Int J Sports Nutr Exerc Metabol. 19:79-96.