Disappointing Results in 28-Day Creatine + β-Alanine Study: No Performance Benefits, No Muscle Gain, No Fat Loss, No Increase in Phosphocreatine & Carnosine in 32 Women

Let's take a closer look at the study and find how it was possible that two proven ergogenics "failed".

Creatine and beta-alanine belong to the few "proven ergogenics", but according to the latest study from the University of Pittsburg, the Texas Christian University, the University of Wisconsin – La Crosse and the Texas A&M University they are not as effective as some of us may think. Specifically the effects of beta-alanine which was tested in what you may call its "comfort zone", i.e. a graded exercise test on the cycle ergometer for VO2peak with lactate threshold determination, and multiple Wingate anaerobic capacity tests. And still, the overall results of the study is that there a "no consistent additive benefits of BA [beta alanine] and CRE [creatine] supplementation in recreationally active women.
In today's SuppVersity article, we are going to have a closer look at the study design, its outcomes and potential explanations for the absence of the highly desirable performance enhancing effects of these two (alleged) ergogenic powerhouses.

As you may know I am not a fan of beta alanine, anyway. Yet despite my alleged bias, I have to admit that the wingate tests the scientists used to determine the effects of the supplementation protocol may have been too short for BA to work. In the most comprehensive meta-analysis of the research to-date, Hobson et al. (2012) found that there are no ergogenic effects to beta alanine on exercises lasting less than 60s or more than 240s; and in the "ergogenic" 60-240s zone, the performance benefit is only 2.85%.

Figure 1: In view of the short study duration it's no wonder that there were no significant effects on body fat and lean mass, but the fact that the beta alanine only group actually gained fat after an initial high loss of body fat is still awkward - still, statistically significant was only the time effect, which tells you that exercise works (Kresta. 2014).

And as far as the absence of benefits of creatine are concerned. The results of the study are in line with previous experimental evidence like that presented by Green et al. who report in their 2001 article in the The Journal of Strength & Conditioning Research that...

"[...] short-term Cr supplementation does not enhance MP and PP during repeated upper-and lower-body Wingate tests when not accompanied by an increase in body weight." (Kresta. 2001)

Similarly, Hoffman et al. (2008) could not find perfomance benefits of short-duration beta alanine supplementation in college football players, what the scientists from the College of New Jersey did find, though was an increases training volume and reduces subjective feelings of fatigue in their highly trained subjects in response to the ingestion of 4.5g/day of beta alanine (Hoffman. 2008).

All in all, the results are thus less surprising than they appear to be...

... at least for those of you who don't believe in the unsustainable promises of the supplement industry, but rely on experimental evidence, only. For creatine, the scientists tested the wrong type of exercise. For beta alanine the exercise duration (60s) on the wingate tests was not long enough to show significant performance increases.

Figure 2: Non-significant (!) changes in carnosine (should increase with BA supplementation) and phosphocreatine (should increase with creatine supplementation) in the BA, BAC, CRE and placebo group (Kresta. 2014).

What the previous brief review of selected experimental evidence does not explain, though, are (a) neither the beta alanine, nor the creatine or combined supplementation lead to statistically significant increases in carnosine (via beta alanine) or phosphocreatine (via creatine), (b) the levels of phosphocreatine the high energy resource, that is believed to be responsible for most of the beneficial effects of creatine actually dropped after 2 weeks on maintenance dose of 0.1g/kg creatine, when it was administered after a 0.3g/kg creatine pre-load. These results stand in contrast to previous studies, like...

• Harris and colleagues (2001) who reported that β-ALA supplementation (3.2 g/day) resulted in a 42% increase in muscle carnosine levels after four weeks of supplementation not due to the fact that the carnosine levels didn't increase, but rather due to the fact that the scientists did not find statistically significant interactions among groups in muscle carnosine levels.
  
  As Kresta et al. (2014) point out, "the lack of statistical significance was apparently due to the large variability in muscle carnosine levels observed in response to β-ALA supplementation, assay variability, and/or inadequate sample size", so that "[m]ore research is needed to determine the effects of β-ALA supplementation on muscle carnosine levels in recreationally-active women" (Kresta. 2014).
• Greenhaff et al. (1994) or Harris et al. (1992) who found significant increases in phosphocreatine with similar preloading + maintenance creatine supplementation schemes as the one used in the study at hand, but yielded significantly higher and above all consistent increases in creatine of up to 40% . Results from the present study found non-significant increases in muscle PCr of up to 40%
  
  Again, Kresta et al. suspect that "the lack of significance may have simply been a result of the small sample size", but add that "it is also known that there is individual variability in response to creatine supplementation" (Kresta. 2014) - a fact that is imho unlikely to be a likely cause of the lack of effect in all subjects, though.

Overall it is thus difficult to determine the lack of consistence improvements in carnosine and phosphocreatine levels in the study at hand, it may yet, as Kresta et al. suggest also be possible...

A study by Everaert, et al. indicates that women have naturally lower carnosine levels (Evaerart. 2011 | see figure abvove). Previous studies, e.g. Tallon (2006), however, found no such difference which is interpreted by Harris et al. in their 2012 review as evidence that "that the apparent gender difference reported by Everaert et al. (2011) may have been simply due to a higher type I:II ratio in females in the voxel sampled." (Harris. 2012)

"[...]that sex may have played a role in response to creatine and/or β-ALA supplementation. In this regard, most studies on creatine and β-ALA supplementation have been conducted on males and there is some evidence that females may respond differently to creatine and/or β-ALA supplementation. For example, Fosberg and colleagues (Forsberg. 1991) reported that females had greater total creatine amounts relative to tissue weight; however, other studies show there is no difference between males and females (Forsberg. 1991; Stegen. 2014).

There are also some data suggesting that men may have greater muscle carnosine levels than women (Derave. 2002; Harris. 2012); however, a recent study showed sex did not have an effect on increasing carnosine levels with supplementation (Stegen. 2014). Additionally, Bex and coworkers (2014) reported that carnosine loading is more pronounced in trained versus untrained individuals" (Kresta. 2014).

It is thus possible, but imho again not very likely that the fact that the subjects in the study at hand were women and or their individual training status may have had and impact on the hardly existing response to creatine and/or β-ALA supplementation.
References:

• Bex, Tine, et al. "Muscle carnosine loading by beta-alanine supplementation is more pronounced in trained vs. untrained muscles." Journal of Applied Physiology 116.2 (2014): 204-209.
• Derave, Wim, et al. "Muscle carnosine metabolism and β-alanine supplementation in relation to exercise and training." Sports medicine 40.3 (2010): 247-263.
• Everaert, Inge, et al. "Vegetarianism, female gender and increasing age, but not CNDP1 genotype, are associated with reduced muscle carnosine levels in humans." Amino acids 40.4 (2011): 1221-1229.
• Green, J. Matt, et al. "The effects of creatine supplementation on repeated upper-and lower-body Wingate performance." The Journal of Strength & Conditioning Research 15.1 (2001): 36-41.
• Harris, Roger C., et al. "The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis." Amino acids 30.3 (2006): 279-289. 
• Harris, R. C., et al. "Determinants of muscle carnosine content." Amino acids 43.1 (2012): 5-12.
• Hobson, Ruth M., et al. "Effects of β-alanine supplementation on exercise performance: a meta-analysis." Amino acids 43.1 (2012): 25-37.
• Hoffman, Jay R., et al. "Short-duration< i> β</i>-alanine supplementation increases training volume and reduces subjective feelings of fatigue in college football players." Nutrition Research 28.1 (2008): 31-35. 
• Kresta, Julie Y., et al. "Effects of 28 days of beta-alanine and creatine monohydrate supplementation on muscle carnosine, body composition and exercise performance in recreationally active females." Journal of the International Society of Sports Nutrition 9.Suppl 1 (2012): P17.
• Stegen, Sanne, et al. "The Beta-Alanine Dose for Maintaining Moderately Elevated Muscle Carnosine Levels." Medicine and science in sports and exercise (2014).
• Tallon, Mark J., et al. "Carnosine, taurine and enzyme activities of human skeletal muscle fibres from elderly subjects with osteoarthritis and young moderately active subjects." Biogerontology 8.2 (2007): 129-137.