Top Foods for Improved Training Performance – Part 2
Nutrition is the language of our cells –it dictates how we look, feel, function and perform. It is drastically undervalued when compared the uncountable list of benefits proper nutrition can yield. For this reason, I have decided to write about my top choices of foods that support physiological or neurological changes to favour improved training performance.
Since over one month has passed since my last article, Part 2 of ‘Top Foods for Improved Training Performance’ includes 2 additional foods. The last article was not suitable for vegetarians or vegans, therefore I have ensured that all foods chosen are applicable to these dietary requirements. In no particular order of importance, I am covering Brazil Nuts, Raisins, Seaweed, and Coconuts.
Brazil Nuts contain 1917mcg of selenium per 100g, making it the most bioavailable source of selenium on the planet. Selenium is implicated in the iodothyronine deiodinases function; this enzyme is required for the conversion of T4 to T3 which is four times more metabolically active. Selenium deficiencies can potentially be indicated on blood work by increased levels of T4 and a reduction of T3. If one is deficient in selenium, it will result in poor thyroid function which is commonly associated with poor muscular performance, weakness, fatigue, poor concentration, poor androgen levels and a slower metabolism – however selenium goes much further than just thyroid functionality, making this a key micronutrient for performance.
Some animal studies suggest that selenium deficiency is independently associated to growth retardation, through the compromise between T3 availability and GH/IGF-1 axis (Moreno-Reyes R., Egrise D., Nève J., Pasteels J.L., Schoutens A.).
Several minerals; namely magnesium, selenium, and zinc, appear to be crucial in IGF-1 bioactivity which modulates growth hormone secretion. GH/IGF-1 signalling is essential for the maintenance of anabolic processes and therefore adaptation for improved performance and development.
Recent findings support the hypothesis of a possible role of selenium in IGF-1 bioactivity. A recent study (Maggioet al.) explored this hypothetical link in 951 participants. This study found a strong correlation between selenium and IGF-1 levels in older adults that was independent of age, sex, body mass index, total energy and alcohol intakes, smoking, alanine aminotransferase, thyroid stimulating hormone, free thyroxine, and free triiodothyronine, CRP, IL-6 and the major chronic diseases (congestive heart failure, chronic obstructive pulmonary disease, and cancer). Therefore, further supporting selenium being capable of modulating IGF-1 bioactivity.
Selenium deficiency worsens during increased NF-κB activity, this mechanism can up-regulate IL-6, which subsequently has a negative influence on IGF-1 levels.
Selenium has a wide range of multiple functions on cells and tissues. It integrates into 25 selenoproteins. These are involved in the glutathione peroxidases family, a group of antioxidant enzymes which plays an integral role in detoxification, reducing oxidative stress, limits neurodegeneration and is essential for maintaining health within the body.
These selenoenzymes, such as glutathione peroxidase and glutathione reductase, protect tissues from oxidative stress which also positively affect the rate of IGF-1 cell-release – further supporting the regulation and bioactivity of IGF-1 (Helmersson J., Arnlov J., Vessby B., Larsson A., Alfthan G., Basu S. Serum).
Selenium may contribute to skeletal muscle function through the maintenance of an optimal concentration of glutathione peroxidase and other selenoproteins, located in endoplasmic reticulum that regulates calcium mobilization required for muscle development (Reeves M.A., Hoffmann P.R. The human selenoproteome: Recent insights into functions and regulation).
It also appears that selenium has a role in grip strength. Low serum selenium concentrations are associated with poor grip strength among older women. This most likely resonates through to the younger generation but is more prominent in the older aged. Due to this association, I think it is fair to hypothesize that if one has a selenium deficiency, it is most likely that deadlift performance (which requires a strong grip) will be far from optimal, accompanied with most back exercises. (Beck J., Ferrucci L., Sun K., Walston J., Fried L.P., Varadhan R., Guralnik J., Semba R.D.).
Data analyzed (Lauretani et al.) from 891 participants found a linear association between plasma selenium levels and muscle strength, namely hip flexion and hip extension for lower extremity muscle strength, shoulder adduction and handgrip for upper-extremity muscle strength. After adjustment for age, sex, BMI, total energy intake, chronic diseases, and IL-6 levels, participants in the lowest quartile of plasma selenium concentration had a greater risk of poor knee, hip, and grip strength decline than those in the highest quartile.
Selenium is also an essential cofactor of multiple metabolic pathways. After being transformed into its bioactive metabolites, selenium acts on the nuclear transcription factor NF-κB, signal transduction, cell cycle checkpoint and apoptosis – therefore essential in the regulation of cell health.
The accumulation of damage at the mitochondrial level and nuclear DNA is one of the main hypotheses by which loss of myocytes and consequently impaired skeletal muscle function becomes apparent. Selenium is an important cofactor in cellular protection, particularly involved in muscle protection, especially within elderly individuals, where cellular oxidative damage is more prevalent.
Now back to Brazil Nuts, in just 100g, there is over 300mg of Magnesium – bringing more than 75% of the recommended daily allowance. Magnesium is required in more than 350 biomechanical reactions inside the body, improves insulin sensitivity that enhances the uptake of nutrients which assists in function and recovery and is also used to create energy in the form of ATP.
Magnesium supports activation of catechol-o-methyltransferase, this assists with the elimination of dopamine, norepinephrine and epinephrine (Thus supporting the reduction in likelihood of central nervous system fatigue. CNS fatigue is one of the main factors for decreased training volume, intensity and quality; therefore reduced growth and development from a performance based outcome). It is also vital for GABA functioning (this is essential for recovery from workout to workout – after all, ‘you can only train as hard as you can recover’).
Last but not least, magnesium also plays a role in the active transport of calcium and potassium ions across cell membranes – this function is essential in sending nerve impulse conductions, regulating heart rate and muscle contractions.
The unfortunate side of Brazil Nuts is that they are high in phytic acid – this particular compound has its own pro’s and con’s. It’s commonly known for being classified as an anti-nutrients, dramatically reducing the absorption of certain minerals such as zinc, copper and magnesium. Phytic acid has also been shown to inhibit certain digestive enzymes; amylase, trypsin and pepsin (preventing optimal break down of starch and proteins).
This being said, studies have found phytic acid to have antioxidant properties as a result of inhibiting Xanthine Oxidase and by ‘preventing a formation of ADP-iron-oxygen complexes’ (Life Sci, 2004). Phytic acid has also been found to decrease the inflammatory cytokines IL-8 and IL-6, particularly in colon cells (Acta Pol Pharm. 2012 ) whilst also improving cholesterol levels by reducing triglycerides and increasing HDL cholesterol (S.-H. Lee, H.-J. Park, S.-Y. Cho et al).
I personally like to squeeze the juice of a fresh lemon onto Brazil Nuts to inhibit the phytic acid as I aim to obtain the benefits else where through a balanced nutritional plan – however the option is yours.
200 grams of Raisins contain 9mg of boron. Roughly 0.001% of the Earths crust is boron – not only is boron rare in the Earth, it is also somewhat uncommon in our foods and especially as a supplemental micronutrient.
There is no set RDA for boron as there have been no essential biological roles identified to this micronutrient. This does not mean Boron is useless however. Boron might not be one of the 24 essential micronutrients for human survival, but it still has some interesting benefits in terms of testosterone production.
In a clinical trial, Naghii MR, et al. J Trace Elem Med Biol. 2011, concluded that 10 mg’s of boron every morning for 7 consecutive days had rather impacting effects on improving one’s androgen profile.
After the week had passed, the subjects blood results were compared from day 1 to day 7:
- Free testosterone levels had increased by 28%
- Free oestrogen levels had decreased by -39%
- Dihydrotestosterone (DHT) levels rose by 10%
Naghii MR et al. found that after 10 days of supplementation from 10mg of boron reduced:
- TNFa levels by 19.1%
- High sensitivity CRP by 45%
- IL-6 by 43.9%.
A reduction from these proinflammatory molecules will inevitably result in a more favourable physiological environment for growth, development and recovery. If these inflammatory markers are high, neural capacity will be greatly diminished due to protective mechanisms of the brain to prevent excess damage or injury to the body.
Another study 14 years earlier from the same researcher (Naghii MR1, Samman S. Biol Trace Elem Res. 1997) found that 4 weeks of 10mg boron supplementation showed a trend towards an increase in total testosterone by 11.4%.
These findings make Raisins a fantastic food to implement for optimising androgen profile, leading to improved strength and favourable body composition changes.
Raisins are also loaded with potassium (749mg per 100g). Approximately 98% of potassium within the body is found within cells, being present with very high concentrations in muscles, bones, liver and red blood cells. Potassium helps draw nutrients intra-cellular and increases cell hydration – these two factors are imperative for cell/muscle functionality and recovery (Walker HK, Hall WD, Hurst JW).
Potassium is key for muscle contractions, nerve impulse transmission, normal heart functioning, prevention of excessive fluid retention, maintenance of proper pH within the body and normal growth and muscle building (Christian Demigné. 3Houda Sabboh, Christian Rémésy, and Pierre Meneton*).
Potassium is also required for the conversion of carbohydrates, proteins, and energy in the form of adenosine triphosphate (ATP) (Harry G. Preuss, and Dallas L. Cloutatre).
Seaweed is naturally loaded with iodine, a nutrient missing from most foods, and is unfortunately vital for well-being and effective metabolism. Nearly 70% from 737 samples tested were below 100ug/L (this is the acceptable minimum level defined by the World Health Organisation).
Iodine is essential for your thyroid gland to maintain functionality, iodine is bound to four tyrosine molecules to make T4, this then subsequently converts to T3 (the more active thyroid hormone). Fortunately tyrosine is an amino acid abundant is red meat and eggs, however iodine is a mineral with poor availability with around 60% of iodine stored within the body is found within the thyroid gland – this shows the sheers value iodine has to supporting thyroid function.
Having a poor iodine intake can quite easily lead to a dysfunctional thyroid with symptoms ranging from fatigue, muscle weakness, weak performance and poor androgenic profile. This gland is seen as the “pace setter” of the body – it regulates metabolism throughout your entire body, development of both your skeleton and brain, improves insulin receptor expression, aids absorption of micronutrients, it is critical for neurotransmitter function, HCl production, it increases mitochondrial density, required for appropriate function is required for the production of ATP and modulatation of SHBG.
The ‘Journal of Neuropathology and Experimental Neurology’ found that ‘newborn rats raised on a commercially available iodine-deficient diet developed severe muscle weakness’ – showing the critical need for iodine and performance.
In 100g of Seaweed laver provides 92mcg iodine, this sits in the middle of the RDA which ranges from 75-150mcg (you have to bare in mind that these levels are based on the minimum amount needed to prevent goiter – a thyroid disease usually stemming from a lack of iodine).
With iodine, it is important to find the sweet spot as too much (consuming over 500mcg) has been shown to supress thyroid function (lowering serum T4 and T3) contrary to the lower dosage supporting thyroid function.
Sources: Society for Endocrinology. New study suggests UK is now iodine-deficient. Press Release. 12 April 2011. – Vanderpump M Lazarus J Smyth P Burns R Eggo M Han, T et al. Assessment of the UK iodine status: a national survey. Endocrine Abstracts. Presented at the Society for Endocrinology BES 2011: 11 April 2011-14 April 2011.
Coconut oil is classed as “thermogenic” (this means the increase of energy expenditure) (St-Onge MP, et al. Int J Obes Relat Metab Disord. 2003.).
Coconut oil is composed of 65% medium chain triglycerides. MCT’s are fatty acid chains which are shorter in length and broken down at a slightly faster rate than usual fats thus giving faster, more readily available energy when compared to usual fat sources. This makes it great to include in your pre-workout meal as this will help keep insulin levels low whilst getting still obtaining energy from the fat source. MCT oils have been found to increase metabolism and fat loss time and time again throughout numerous studies (Stubbs RJ, et al. Int J Obes Relat Metab Disord. 1996).
The consumption of Coconut Oil led to a 35% decrease in C-reactive protein, a marker of inflammation (Assunção ML, et al. Lipids. 2009), which if left high and unmanaged impairs muscle function, performance and recovery. Dr Florentino Herrera compares the anti-inflammatory similar to that of aspirin (Jr. Medical Library, The Philippine Journal of Internal Medicine. 2007).
Medium chain triglycerides within in Coconut Oil have been found to increase the respiratory capacity of mitochondria without adding any additional oxidative stress from the increased working function (Montgomery MK, et al. J Lipid Res. 2013). Coconut Oil has also been found to increase mitochondrial energy production in those with defects in mitochondrial fatty acid oxidation (Spiekerkoetter U, et al. J Inherit Metab Dis. 2010). This means that Coconut Oil will promote energy production and utilisation – giving you energy to power your training.
MCT’s have also been shown to improve cognition under conditions of low blood sugar (Page KA, et al. Diabetes. 2009) this is very beneficial for performance based athletes as prior to training, the avoidance of carbohydrates is usually preferred to keep serotonin levels lower than dopamine levels, promoting better neural strength and energy.
MCT’s in Coconut Oil help maintain insulin sensitivity in muscle and fat tissues (Turner N, et al. Diabetes. 2009). Insulin sensitivity is essential for the cellular uptake of nutrients required from the muscle to function and recover. MCTs found in coconut oil were also found to increase insulin-independent metabolism in both diabetic and nondiabetic subjects (Kochikuzhyil BM, et al. Indian J Pharmacol. 2010).
Virgin coconut oil increases glutathione (the ‘mother’ of all antioxidant) levels, thus protecting against oxidative stress (Arunima S, et al. Food Funct. 2013). Excess oxidative stress will lead to neural inhibitation of ones strength output.
Large quantities of Coconut can be an issue for some if they have defects in the APOE gene (such as myself – this is particularly associated to fat metabolism) or other single nucleotide polymorphisms, therefore moderation is key.
Thank you for taking your time to read this article.
Stay tuned for part 3 where I will be moving back into the perspective of a carnivore.
Coach Jake Carter