Friday, April 19, 2013

Science Round-Up 2nds: Intra-/Post Workout Stims, Carbs & Protein and Their Effects on Performance, Hydration, GH, Cortisol, Testosterone & Fatty Acid Oxidation

As mentioned on yesterday's show, small 100kcal packets are as much of a problem as large dinner plates and XXL meals (data based on Coelho do Vale. 2008)
I want to start today's Seconds with a question: How did you like that Carl and I did not rush through the news-lineup as it was the case in previous episodes, but simply took our time to discuss the topics in depth an breadth, yesterday?

Personally, I believe that this is much better than the accumulation of "buzzword" the show had become in the previous weeks due to my "study hunter and gatherer" drive - or, in other words, the mere mass of studies I wanted to pack into the show and Carl's desperate effort to cover them all.

Would you agree? And what other changes / improvements would you like to see in the future? We are open for constructive criticism. You can't improve your game without it.

Let's get to what did not fit into the show, then...

The net result of the spending more time on each and every of the single items, or, to say it in the spirit of yesterday's show, a bit more mindfulness was obviously a much larger amount of Seconds for you to devour today. So, let's not waste any time and get right down to business:

  • Is 200mg of caffeine the optimum!?A 2008 study by Beavan et al., which involved 24 professional rugby players who were randomly assigned to receive 0, 200, 400 or 800mg of caffeine 1h before performing a standardized resistance training protocol (Beavan. 2008), found that contrary to what bro-science has been suggesting for years, the ingestion of the high amounts of caffeine (800mg) lead to a profound drop in the testosterone-to-cortisol ratio, while the lower doses of 200mg and 400mg of caffeine only blunted the performance hampering decline of cortisol half-way into the workout, while increasing the testosterone levels by 15%
    Caffeine or pseudoephedrine for performance enhancement? As far as improving you game is concerned, a recent study from the School of Sports Science at the department of Exercise and Health of the University of Western Australia was able to show that you are only wasting your time an money, if you are trying to up your cycling-time trial and thus probably every other HIT performance by ingesting the purported CNS stimulant pseudoephedrine (not to be confused with the "real deal"; cf Spence. 2013).

    Contrary to the comparatively low amount of 200mg caffeine, which allowed the 10 well-trained cyclists and triathletes who participated in the study improve their TT times in trial 2 of 3, all of which were performed on th same day, by statistically significant 57s, the ingestion of the WADA banned substance pseudoephedrine at a dosage of 180g would have cost them their license for nothing.
    Bottom line: Spare yourselves pseudoephedrine and other nasal/sinus decongestant belonging to the the class of phenethylamines and amphetamines (e.g. geranium). Even if others worked (for 1,3-dimethylamine this has never been proven in isolation), the long(er)-term detrimental effects they'll have on your central nervous system really isn't worth it.

  • Protein-enhanced Gatorade ain't worth your money -- If you are no ultra-endurance runner or at least marathon runner, you don't need, because you don't benefit intra-workout carbohydrate + electrolyte + protein (CEP) drinks for hydration.

    The results of a recent study from the Chinese University of Hong Kong show: A CEP solution containing 42g/L carbohydrate, 21g/L whey protein and 15.3 mmol/L sodium and 2.3 mmol/L potassium does not show "extra benefits for the maintenance of hydration status during 60 min cycling" (Sun. 2013)

  • Carbohydrate + protein drinks maximizes GH response to exercise -- Now that you know that it's not worth to guzzle on carbohydrate + electrolyte + protein drinks during a workout for hydration purposes, I guess I should tell you that doing the same (w/out the electrolytes, though), may still provide an athletic / anabolic edge. After all, another recently published study that was conducted at the School of Sport at the Department of Exercise and Health Sciences of the Loughborough University in Leicestershire, U.K (Betts.  2013) shows that the ingestion of a carbohydrate + protein mixture (CHO+PRO: 0.8 g sucrose per kg bod weight per hour + 0.3 g/kg/h whey protein isolate) in the 4h recovery period between two exhaustive treadmill runs at the same intensity augmented the growth hormone response by 60%(!) compared to the ingestion carbohydrate only (0.8 or 1.1g of sucrose /kg per hour).
    Figure 1: Growth hormone (GH) and cortisol response to 2nd bout of exhaustive treadmill running with either 0.8 or 1.1g of sucrose /kg per hour (CHO, CHO-CHO) or  0.8 g/kg/h sucrose per kg bod weight per hour + 0.3 g/kg/h whey protein isolate (CHO+PRO; cf.
    As the data in figure 1 goes to show you this increase in GH was accompanied by a 23% reduction in cortisol. With both, GH and cortisol being released in response to the depletion of muscle glycogen and impeding low blood glucose levels (Galbo. 1977), you could thus argue that protein (probably by its glucagon promting effects; cf. Claessens. 2008) programs the "anabolic glucose procurement plan".

    Bottom line: Yet another reason for the often touted, yet tried and proven "Bananas + whey" = WIN! And that's not true wrt to the protein anabolic response after a workout, but also in view of the "anabolic" or I should probably say generally more favorable way of glucose procurement during subsequent workouts.

  • No, no and no! The ingestion of carbs before a HIIT workout will only increase, not blunt the fatty acid oxidation in the post-workout period.
    Pre-workout carb ingestion does not blunt, but promote fatty acid oxidation after the workout -- In as much as this result may go against common bro-science that you must never consume any carbs before your workout if you are trying to lose body fat, it is actually in line with what I have been preaching before. The beneficial effects of AMPK come with the depletion of ATP and the rise in ADP (~used ATP), not with the constantly depleted ATP stores of a no-carbohydrate + protein only starvation diet. Or put more simply - a constant over-expression of AMPK negates all the benefits of it's cyclic up and down (cf. "The mTOR/AMPK Seesaw"; read more)

    While the scientists from the Department of Nutrition & Metabolism at the Faculty of Health and Medical Sciences of the University of Surrey in Guildford, UK, did not observe statistically significant improvements in fatty oxidation due to the small study size (10 healthy untrained females; age 18–22 yr; BMI 22kg/m²), the pronounced decrease in RQ after 8-10x 60 second cycling bouts at 95 % VO2peak separated by 90 seconds recovery at 50 watts in 9 out of 10 participants (see figure 2) does speak itself: "In women, consuming carbohydrate before exercise may potentially be more beneficial for fat oxidation than consuming carbohydrate post-exercise" (Honnor. 2013).

    Bottom line: The results of the study at hand, which stand in line with previous research by Fuchs et al. who presented their research in the Proceedings of the Nutrition Society one year before, re-emphasis the fallacious over-reliance of high fatty oxidation rates during a workout. The max. 60-90min in which you may burn slightly more fat, are simply negligible compared to the much longer post-workout period, where the ingestion of 59 g CHO before a HIIT workout did not blunt but promote fatty acid oxidation.

Believe it or not, but that's it for today! If you are hungry for more, I suggest you either go to the SuppVersity Facebook Wall or listen to Casual Friday later today... actually, I found Gabriel's name, i.e.  "The Alisa Profumo Show", for the Friday edition of Super Human Radio show quite fitting ;-)

  • Beaven CM, Hopkins WG, Hansen KT, Wood MR, Cronin JB, Lowe TE. Dose effect of caffeine on testosterone and cortisol responses to resistance exercise. Int J Sport Nutr Exerc Metab. 2008
  • Betts JA, Stokes KA, Toone RJ, Williams C. Growth Hormone Responses to Consecutive Exercise Bouts with Ingestion of Carbohydrate plus Protein. Int J Sport Nutr Exerc Metab. 2013 April. 
  • Claessens M, Saris WH, van Baak MA. Glucagon and insulin responses after ingestion of different amounts of intact and hydrolysed proteins. Br J Nutr. 2008 Jul;100(1):61-9.
  • Coelho do Vale R, Pieters R, Zeelenberg. Flying under the Radar: Perverse Package Size Effects on Consumption Self‐Regulation. Journal of Consumer Research. 2008; 35(3):380-39.
  • Fuchs, A. & Young, H. Investigation into gender differences in the effects of feeding around exercise on exercise performance, energy expenditure and substrate utilisation. Proceedings of the Nutrition Society. 2011; 70 (OCE6), E380.
  • Galbo H, Richter EA, Hilsted J, Holst JJ, Christensen NJ, Henriksson J. Hormonal regulation during prolonged exercise. Ann N Y Acad Sci. 1977;301:72-80. Review.
  • Honnor M, Herdsman M, Collins AL.The effect of food timing on fat oxidation during exercise and resting recovery. Proceedings of the Nutrition Society. 2012; 71 (OCE3), E236 
  • Spence A, Sim M, Landers G, Peeling P. A Comparison of Caffeine versus Pseudoephedrine on Cycling Time-Trial Performance. Int J Sport Nutr Exerc Metab. 2013 Apr 9. 
  • Sun, F; Li, L; O’Reilly, J; Wong, SH. Effect of carbohydrate-electrolyte-protein solution on hydration. International Journal of Sport Nutrition and Exercise Metabolism. 2013; 23: S1-S15