Saturday, August 3, 2013

Colostrum Maintains Testosterone, Cortisol and Heart Rate Recovery, Where Whey Fails - During a Five Day Cycling Event With 10 Highly Trained Male Road Cyclists

Legal gear fresh from the udder? If it works for cyclist, it must be real ;-)
Some of you will probably remember the corresponding installment of "Ask Dr. Andro" from 2011 that dealt with the question whether colostrum and milk products in general are healthy muscle builders, a waste of money or toxic waste (read more). If you do, you will also remember that my review of the literature did support the general benefits of milk proteins, but it did not provide significant evidence that benefits that have been observed in the few existing studies on the ergogenic value of colostrum could not be achieved by whey and/or casein proteins as well. Now, the latest study from the University of Queensland appears to suggest that just this could yet in fact be the case (Shing. 2013) - at least if the outcome measures are the salivary testosterone concentration and modulated autonomic activity over consecutive days of competitive cycling.

10g of whey vs. 10g of cholostrum "isolate"

The scientists from the School of Human Movement Studies recruited 10 highly trained cyclists with an average age of 22.5y and a body weight of ~70kg and put them on two different supplemental protocols
  • the control group received consumed 10g whey protein concentrate (“Alacen® 80” Fonterra Co-op Group Limited, Auck- land, New Zealand) per day 
  • the colostrum group consumed 10 g Intact® bovine CPC (Numico Research Australia Pty Ltd, South Australia) per day
Neeldess to say, both supplements were isocaloric, packed in identical sachets to and had to be used for the same timespan, which were the 8 weeks prior to and the whole five days of the cycle race that was used as the litmus test for the efficacy of the supplementation regimen.

Colostrum muscle builder or murky allergen (learn more)?
In that it, may be worth adding that the cyclists consumed the in the morning mixed with 50 mL of water and 100 mL of skim milk and that the scientists picked Intact® CPC 3-6, 14 as their colostrum supplement of choice, because the various available products vary largely in their amino acid and protein content. Therefore it appeared sensible to use the same brands that have been used in previous studies, as well. According to Shing et al. Intact® is a standardized, low heat  treated, low fat, low lactose colostrum powder containing 20%  IgG that retains both casein and whey proteins (just as a side note: there was no sponsorship involved in the study, although the brand names may suggests otherwise).

Aside from the objectively measurable saliva responses, the scientists had the participants fill diet and training, as well as illness logs. The latter reflects the hypothesis that the IgG content in the colostrum would strengthen the immune system of the cyclists and should thus result in lowered infection rates. With two vs. four illnesses in the whole study period the differences between the colostrum (2 illnesses) and the whey group were yet statistically not significant.
Figure 1: Change in heart rate recovery (left), salivary testosterone and cortisol levels (right) during the 5-day cycling event (Shing. 2013)
Much contrary to whey group, where the naturally cyclic testosterone rhythm is completely lost and the cortisol rhythm attenuated, both remained intact in the colostrum group. This goes hand in hand with the loss of heart rate variability in the whey control and the increases of the parameter in the colostrum group. Both results in conjunction with the smaller reduction in vigor and the ameliorated change in fatigue in the colostrum group clearly suggest that the cyclists in the whey group were already parasympathetically overtrained, while the stress reducing effects colostrum kept the cyclists in the active arm from falling into the same trap.

For short time-trials sodium bicarbonate may be the supp of choice (learn more).
Bottom line: The scientists state it in their conclusion "the number of participants in this pilot study was small", too small for my liking, so that it is - as a standalone - simply not enough to prove anything.

The scientists are yet right that "the present data support the potential for bovine CPC supplementation to maintain testosterone concentrations and influence heart rate variability response" in a training regimen that is notorious for its negative impact on the central nervous system and the HPTA. "Support" and "potential" - not more, but not less either.

  • Shing CM, Peake JM, Suzuki K, Jenkins DG, Coombes JS. A pilot study: bovine colostrum supplementation and hormonal and autonomic responses to competitive cycling. J Sports Med Phys Fitness. 2013 Oct;53(5):490-501.