Leucine and Strength

Leucine regulates muscle protein synthesis through the mammalian target rapamycin (mTOR), which influences cell growth. Also, evidence points to increases in collagen synthesis by supplementing leucine. The improvement in muscle protein synthesis and collagen synthesis suggest faster recovery rates from high intensity training. The ability to recover faster may allow the person to train more frequently.

There is a metabolite of leucine called Beta-Hydroxy-Beta-methylbutyrate (HMB) that has shown to increase muscle mass. Yet, there is other research displaying negligible benefits in trained subjects using HMB in respect to strength. On one hand, Portal et al found increases in muscle mass, muscle strength and anaerobic properties in national level volleyball ball players after supplementing with 3 g/day of HMB. On the other hand, an article from The Journal of Strength and Conditioning Research reported no effect on muscular power strength and endurance. However, experimental research that treated rats with HMB demonstrated an increase in extensor digitorum muscle and an increase in mTOR expression, but induced a significant rise in fasting insulin. Here is study investigating long term usage of HMB in rat models that eventually lead to insulin resistance and hyperinsulinemia. It appears that HMB may not provide much of an advantage toward improving athletic performance or increases in strength in highly conditioned athletes even when combined with creatine, according to the research here, here and here.

L-Carnitine and Overall Health

L-carnitine may provide protection from lipid peroxidation and oxidative stress. There is some evidence claiming that L-carnitine can reduce biochemical makers related to oxidative stress such as nitrite concentration and malondialdehyde. Lipid peroxidation and oxidative stress may be related to chronically high levels of glucose and insulin sensitivity. Researchers reported in the Turkish Journal of Endocrinology and Metabolism that demonstrated a decrease in blood glucose after 12 weeks of L-carnitine supplementation. The participants were given 3g/per day and were type 2 diabetics. Here is in an interesting paper describing how L-carnitine improves glucose disposal in human subjects. Strangely enough, there is evidence from ponies taking 4g/per day of L-carnitine that reveled a decrease in postprandial plasma glucose and insulin concentration. According to Alesci et al, L-carnitine supplementation may enhance "modulation of the immune system and other glucocorticoid-like effects."

From a perspective of athletic performance there may be some advantages with supplemental L-carnitine as a means toward recovery. For example, Karlic & Lohinger reported in their review that L-carnitine appeared to attenuate "accumulation of creatine kinase", decrease catabolism of purines, free radical formation and sarcolemma disruption. The most muscle damage occurs during the eccentric phase in relation to the movement being performed. Giamberardino et al claim that L-carnitine reduced pain in association to eccentric type of exercises by ameliorating levels of creatine kinase and improving vasodilation.

Human Origins of Ancestral Diets

There was a fascinating paper published in the Proceedings of the Royal Society viewing the human genome in relation to the evolutionary changes in diet. The researchers of this study speculate that selective differences may have been influenced by diet. An increase in meat and starchy plants may be responsible for selective differences among human populations. Interestingly, archaeological records demonstrate evidence of the Homo erectus having the ability to extract bone marrow by means of stone tools. Furthermore, calorie dense oil rich seeds were obtained by H. erectus as well. However, it is difficult to know the type of meats and starchy plants that were available throughout seasonal changes and the various ratios of macronutrients. Other evidence that establishes a change reflecting consumption of meat is through dental traits but the interpretation of these studies remain inconclusive.

The allele frequencies have been known to shift in accordance to different diets. The previous study points to other researchers that found in their results "significant shifts in allele frequency" in association to diets rich in roots and tubers. Yet, it seems clear from Leonard et al that meat was responsible for metabolic adaptations and evolution of the brain.

The Physiological Advantages of High Intensity Training

The physiological benefits of high intensity training may vary because of the difficulty of measuring the exact nature of high intensity. Some investigators from The University of Western Ontario explored some of the power outputs in efforts that lasted 10 s with a 2 minuet rest, and in a group that performed for 10 s with a 4 minuet rest on a mechanically braked ergometer. There were other subjects that were assigned to different times and rest periods but the primary focus for this post will look at the 10 s efforts. The ability to reproduce maximal power outputs over an extended period of time may provide a better training stimulus than one that declines throughout the workout. Interestingly, the group in the 10s:2 minuet rest maintained 95% of their peak power output and the 10s:4 minuet rest demonstrated 96%. The researchers speculate that peak power output occurs within the interval between 5 s and 10 s, suggesting that the physiological benefits are stimulated quickly, rather than in total work performed. In addition, these short intense efforts display similar outcomes as longer aerobic type exercises in respect to biochemical adaptions such as mitochondrial biogenesis.

Is there any supplements that may improve high intensity training? There is theoretical and experimental evidence supporting D-ribose as a possible ergogenic aid toward enhancing high intensity training. Furthermore, creatine may restore higher power output quicker and a faster post recovery from workouts. For instance, Cooke et al discovered faster muscle recovery in subjects consuming creatine by witnessing higher strength values recorded after exercise induced muscle damage via eccentric loading. The mechanism in which the recovery takes effect is thought to occur during gene transcription by means of amino acid pools.

Soy Lecithin and Corn oil Influence Behavior

There is a rather interesting article published in the Journal of Animal Science that investigates the behavior of horses fed soy lecithin and corn oil. The researchers discovered that the horses fed soy lecithin and corn were "less spontaneous" and showed slower reactivity toward exercise. Strangely enough, both soy lecithin and corn oil is found in regular food eaten by people throughout the country. Is it possible to theorize a connection between this animal study and relate it to the human population? It is difficult to bring a comparative observation between a person and a horse, but there is other research suggesting that soy lecithin may disrupt sensorimotor development and brain cell maturation. Even though, this study was performed on rats it hints to a possible mechanism being altered by some thing in the soy lecithin.

Corn oil in the food chain is most likely contributing to systemic inflammation, which is possibly affecting behavior in relation to its high level of linoleic acid. Unfortunately, there is soy and corn products in infant formula. Research reported in The American Journal of Clinical Nutrition demonstrates that infants were able to obtain higher intakes of docosahexaenoic acid (DHA) as result of being breast fed compared to infants fed formula. DHA was found to improve retinal physiology and neural function. However, most infant formulas on the market have DHA but still contain soy and corn derivatives, which could counter the benefits of DHA.