|Rowing is an excellent cardio exercise for wanna be bodyuilders, by the way!|
Against that background I have to admit that I am not exactly unhappy to tell you that Ga Hee Koo, Jin Hee Woo, Sung Whun Kang, and Ki Ok Sjin who work at the Dong-A University and the Republic of Korea Airforce Academy, have recently observed that BCAAs have absolutely no, glutamine at least a minimal impact on the blood fatigue factor response of juvenile athletes in response to a 2,000 m all out rowing challenge w/ placebo, BCAA or glutamine supps.
In the corresponding experiment, the scientists from the College of Sports Science at the Dong-A University had five male juvenile elite rowing athletes perform the same 2,000m rowing test at maximal intensity after having received a placebo, BCAA, or glutamine for 7 days before
the test. The specific supplementation regimen included:
- BCAA (Spomax, Seoul, Republic of Korea) was given three times a day (25% valine, 50% leucine, 25% isoleucine, 3.15 g/day).
- L-glutamine (Optimum Nutrition, Aurora, IL, USA, 6 g/day) was given three times a day.
Which parameters did the researchers test and why? Koo et al. tested lactate, the accumulation of which will eventually impair ATP synthesis and lead to muscular fatigue. They tested the accumulation and clearance of ammonia, which can trigger central fatigue, when the levels increase rapidly during high intensity exercise. And they tested creatine kinase (CK) which is a classic marker of muscle damage and IL-8 and IL-15, two cytokines that will be elevated, when the activity of the immune system is not sufficient to deal with exercise induced stressors.The actual test was conducted with an indoor rowing machine (Concept², Morrisville, VT, USA) two times each for supplementation with the placebo, BCAA, and glutamine. All the subjects performed a 2,000 m (Olympic single scull race) race at their own individual maximum paces (42–45 pace for 0m~250m, 40 pace for 250m~500m, 36–38 pace for 500m~1,500 m, and over 42 pace for 1,500 m~2,000 m)
|Figure 1: Serum markers of fatigue and muscle damage, expressed relative to placebo (Koo. 2014)|
The dosages are not the same! That's unfair! No, it's not necessarily unfair, but it would still have been better to test 18g of glutamine vs. 18g of BCAAs. There is after all one thing both have in common: They both can be used as workout fuel in the muscle, so the advantage of glutamine may have become smaller (maybe even non-significant), if both had been administered at the same amounts.The creatine kinase levels (a marker of muscle damage) and the levels of interleukin-8 and interleukin-15, however, were significantly lower in the glutamine than they were in either the BCAA or placebo group. This is a result of which the authors of the study believe that, it may...
"[...]represent the effects of energy supplementation from glutamine supply, which activated as a fuel in the muscle and as a nitrogen precursor for nucleotide synthesis" (Koo. 2014).An alternative explanation would be that glutamine (probably via its connection to glutathione; see Roth. 2002) had a direct protive effect on the skeletal muscle tissue during the workouts.
|Figure 2: Serum levels of inflammatory cytokines expressed relative to placebo (Koo. 2014)|
|Table 1: Intense exercise is not the only condition / disease that's associated with low blood glutamine levels (Roth. 2002)|
Whether supplementation is warranted with low(er) intensity exercise, as well, is however questionable. Previous research by Ostrowski et al. (2001), who had their subjects exercise at significantly lower intensities, did not find comparable increases in IL-8. This difference is probably due to a comparably lower amount of exercise induced stress that corresponds to the reduced intensity. In this context it's also worth mentioning that Fischer et al. (2006) report that the blood chemokine concentrations would increase little or remain stagnant unless a sufficient muscle mass is mobilized and maintained at a certain level of intensity sufficiently... now, everyone who has ever done an all-out rowing time trial will confirm: This is (a) intense and will (b) involve almost every muscle in your body.
- Fischer, Christian P. "Interleukin-6 in acute exercise and training: what is the biological relevance." Exerc Immunol Rev 12.6-33 (2006): 41.
- Koo, Ga Hee, et al. "Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance." Journal of Physical Therapy Science 26.8 (2014): 1241-1246.
- Ostrowski, Kenneth, et al. "Chemokines are elevated in plasma after strenuous exercise in humans." European journal of applied physiology 84.3 (2001): 244-245.
- Roth, Erich, et al. "Regulative potential of glutamine—relation to glutathione metabolism." Nutrition 18.3 (2002): 217-221.