2009 Studies & Research Blog

Due to poor diet, over consumption of caffeine and alcohol, lack of exercise and a lot of stress, erectile dysfunction (ED) seems to becoming more and more of an issue in older men. Sales of Viagra and Cialis seem to be at an all-time high, and it would appear that men are even investigating the potential of the obviously crappy sex energy products available on the counters of 7-Eleven and gas stations.

                                                 Got wood?
A recent study using 50 patients with mild to moderate ED were treated for one month with a placebo or a combination of l-Arginine Aspartate and Pycnogenol, an extract from the bark of the French Maritime Pine tree. Patients kept sex diaries and answered questionnaires regarding their subjective feelings. Patients using the l-arginine aspartate and pycnogenol noted that their incidence of morning erections increased, as did their ability to initiate and sustain an erection, whereas those using the placebo did not. In addition to this, testosterone levels and endothelial NO synthase (e-NOS) were monitored, and both increased significantly. Researchers also noted that cholesterol levels and blood pressure were both lowered, with no side effects suffered.

Stanislavov R, Nikolova V, Rohdewald P. Improvement of erectile function with Prelox: a randomized, double-blind, placebo-controlled, crossover trial. Int J Impot Res. 2008 Mar-Apr;20(2):173-80.  
    

Are there any methods that may increase beta-alanine’s ability to increase carnosine levels?

Yes. A recent study showed that a group of subjects taking Beta-Alanine with carbohydrates increased performance gains in half the time of the group taking an equal amount of beta-alanine without carbohydrates. Carbohydrates spike insulin and one of insulin’s effects is to increase amino acid (such as beta-alanine) transport into our cells.

While not supported by the research yet, taking beta-alanine pre-workout and post-workout MAY increase the uptake of beta-alanine into our muscles. Amino acid nutrient timing studies have clearly shown when amino acids are ingested pre-workout and post-workout, their delivery and uptake into our muscles is increased. The improved uptake is largely due to increased blood flow during exercise.

What is the prickling I feel when I first take Beta-Alanine?

The prickling - called parathesia - is caused by beta-alanine binding to nerve receptors, activating them and causing them to discharge/fire. Many of these nerves are below the skin, giving a prickling/pins-and-needles sensation. This sensation begins approximately 15-20 minutes after ingesting beta-alanine and usually continues for 1-1.5 hours. The intensity varies depending on dosing, individual sensitivity and potentially from activators of Ca2+ channels, such as caffeine. This sensation, though generally enjoyed, often subsides over a few weeks of continued use. Carbohydrates/food may also blunt the prickling effect from beta-alanine.

If I don’t feel the prickling does that mean beta alanine isn’t working on me?

The prickling sensation does not occur at all in some individuals, even when taking 4-6 grams of beta-alanine at one time.  Do not worry if you are in this group. The prickling is NOT a sign that beta-alanine is working or being absorbed by your muscles and converted to carnosine. If you are feeling nothing, you need not be concerned as it is still increasing your carnosine stores as research has repeatedly shown.

A good example of this phenomenon is when combining carbohydrates with beta-alanine. Not only do carbohydrates blunt much of the prickling sensations, they also increase beta-alanine’s performance gains faster than beta-alanine without carbohydrates.

Another good example is comparing studies that measure carnosine concentrations using multiple small 800 mg doses of beta-alanine vs. studies using multiple doses of 1.6 g of beta-alanine. The total daily amount of beta-alanine ingested is similar and the duration of the studies using both dosage strategies is matched up as well. 800 mg is low enough to cause little to no prickling, based off feedback from both research and anecdotal, where as 1.6 g can cause quite a lot. The outcome of both studies showed carnosine concentrations were very similar.

Posted by: ATHLETIC EDGE NUTRITION

It has been suggested that regular coffee consumption may provide positive health benefits. Coffee can reduce the risk for insulin resistance, type 2 diabetes and cardiovascular disease. To examine this further, researchers at Tottori University in Yonago, Japan studied the effects of coffee on C-reactive protein, an inflammatory marker implicated in various diseases including the ones above. To determine the effects of coffee on C-reactive protein, they recruited  459 community-living Japanese women, aged 23-83 years. The researchers found out that regular coffee consumption lower levels of CRP in the subjects consuming >/=1 cup/day than in that of <1 cup/day. Bottom line here is enjoy your coffee breaks !

Reference:

Kotani K, Tsuzaki K, Sano Y, Maekawa M, Fujiwara S, Hamada T, Sakane N. The relationship between usual coffee consumption and serum C-reactive protein level in a Japanese female population.Clin Chem Lab Med. 2008 Oct;46(10):1434-1437.

Well all know that exercise will help to increase your calorie burn, so theoretically you would at first think it would serve to increase the appetite as well.  This is not the case for many people, however.

Many find that moderate intensity exercise will actually decrease the appetite, making you less likely to overeat during the rest of the day.

High intensity exercise tends to have the opposite effect though, it will decrease appetite initially after it’s completed, however your appetite, you may find, will come back with a vengeance later on during the day.

Recently, researchers out of the School of Exercise and Nutritional Sciences in San Diego looked at the effect the timing of exercise in relation to meal consumption was on the hormonal factors that control the appetite.

The study was designed so that twelve men performed three trials. In the first it was just a meal alone, in the second, it was a exercise that was completed two hours after the meal, and in the third scenario, it was exercise that took place one hour before exercise.

The meal that was being tested provided 16.5kcalkg and was made up of 70% fat, 26% carbohydrates, and 4% protein.

The exercise that took place as part of the study was performed at a work rate of 60% of VO2max for 50 minutes.

After the procedure had taken place, it was demonstrated that the exercise that was performed 2 hours after the meal helped to further suppress the appetite, while exercise prior to food intake decreased appetite and increased the plasma ghrelin concentrations.

It should be noted also that there was no impact on meal timing with respect to the leptin concentration levels in the body.

Therefore, from this study we can conclude that the timing of your meal does have some impact on appetite levels and in particularly the ghrelin concentrations in the body, however, it appears as though exercise in itself will also have an appetite suppressive effect regardless of whether it is performed before or after the workout.

Reference:
Cannon, DT. et al. (2008) Appetite regulation via exercise prior or subsequent to high-fat meal composition. Appetite 2008, Sept 25

It’s well known that cortisol is the stress hormone that is released in the body and can have negative impacts on our health.  

Some of these negative effects include feelings of fatigue and lethargy, the greater chance of accumulation of body fat around the abdominal area, increased cravings for carbohydrates, and an increased risk for colds or other illnesses related to a weakened immune system.

In most people though, the cortisol levels released from exercise is easily dealt with and managed by the body, so it’s not something to get overly concerned with.

When one starts overtraining, however, cortisol definitely becomes more of an issue as the body is not able to keep up with the demands of the workout program.

Recently researchers decided to look how the varying intensities of exercise would impact the cortisol release in the body.  

Most people assume that the greater the intensity you are working at, the more cortisol will be released. But does that mean lower intensities tend not to have much of an impact at all on cortisol?

The study was designed so that eleven healthy, physical active young men would complete an exercise test that involved progressive workload stages to determine what their peak oxygen uptake was (VO2).  

Blood samples were taken at the end of each bout of exercise and cortisol concentration was determined.  

The results of the study demonstrated that cortisol was significantly increased at the end of each exercise stage above normal, however the levels did not significantly different between the stages until the lactate threshold was exceeded.

This study therefore suggests that even lower intensity exercise sessions will release a cortisol response, and will be very similar until you are working at such a high intensity that you are above your lactate threshold.

The take home message to apply then is that even if you are doing ‘light’ days in your workout, thinking that this will allow your body to really recover between your higher intensity days, you may not be recovering as well as you think.

Thus, this information really helps to highlight the importance of complete rest days within your overall workout program.

Reference:
Janson, T. et al. (2008) Characterization of the cortisol response to incremental exercise in physically active young men.  Acta Phsyiol Hung. Jun;95(2):219-27

A recent study conducted by Little et al. assessed  the efficacy of a dietary supplement containing 1) Cr, A-AKG, glutamine, taurine, branched-chain amino acids, and medium-chain triglycerides with 2) Cr alone or 3) placebo on exercise performance and body composition.

Three groups were utilized in this study with 12 subjects in each group.  Body composition, muscle endurance (bench press), and peak and average power (Wingate tests) were measured before and after the supplementation period. The researchers found out that the Bench-press repetitions over 3 sets and peak power increased the greatest in the Cr+ AAKG group

Therefore, the researchers suggest that Cr alone and in combination with A-AKG improves upper body muscle endurance, and Cr + A-AKG supplementation improves peak power output on repeated Wingate tests.

Reference:

Jonathan P. Little, Scott C. Forbes, Darren G. Candow, Stephen M. Cornish, Philip D. Chilibeck Creatine, Arginine ?-Ketoglutarate, Amino Acids, and Medium-Chain Triglycerides and Endurance and Performance. IJSNEM, 18(5), October 2008.

While most people are well aware that getting in enough water is important, few realize just how large of an impact a small case of dehydration can have on your ability to lift weights in the gym.

Researchers out of the Department of Kinesiology in Connecticut recently looked at just this issue.  They designed the study so that there were seven healthy resistance trained males who were to complete three different bouts of resistance exercise in different hydration states.

In one occurrence there were hydrated properly and had a good fluid balance.  In the second occurrence, they were dehydrated to a point that equaled about 2.5% of their total body mass, and in the third state, they were dehydrated to 5% of their total body mass.  

The dehydration was manipulated by using exercise-heat stress and controlling the fluid intake for the day around the exercise training session.

The results of this study demonstrated that when the percentage of total work completed during a six-set back squat regime, both dehydrated groups demonstrated a significantly decreased exercise performance during sets 2-3 (2.5%) and 2-5(5%).

The researchers concluded that this decrease in strength was mostly due to the central activation ratio in the body, thus showing the role of the central drive in producing force output during weight lifting.

Therefore, the take home message with this is that even mild dehydration can have significant impacts on your performance ability.

Reference:

Armstrong, LE. Et al. (2007) Effect of hydration state on strength, power, and resistance exercise performance.  Med Sci Sports Exerc. Oct;39 (10):1817-24.

The International society of sports nutrition position stand have recently presented a statement concerning nutrient consumption and timing to maximize exercise performance. The statement is summarized into eight points based on our current understanding of sports nutrition which are:

1.) Maximal endogenous glycogen stores are best promoted by following a high-glycemic, high-carbohydrate (CHO) diet (600 - 1000 grams CHO or ~ 8 - 10 g CHO/kg/d), and ingestion of free amino acids and protein (PRO) alone or in combination with CHO before resistance exercise can maximally stimulate protein synthesis.

8.) Nutrient timing incorporates the use of methodical planning and eating of whole foods, nutrients extracted from food, and other sources. The timing of the energy intake and the ratio of certain ingested macronutrients are likely the attributes which allow for enhanced recovery and tissue repair following high-volume exercise, augmented muscle protein synthesis, and improved mood states when compared with unplanned or traditional strategies of nutrient intake.

IMO these guidelines should be a staple for anyone interested in maximizing their diets potential in enhancing performance.

Reference:

Kerksick C, Stout J, Campbell B, Wilborn C, Kreider R, Kalman D, Ziegenfuss T, Lopez H, Landis J, Ivy J, Antonio J.International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 2008 Oct 3;5(1):17.

A  study in 2007 compared muscle protein synthesis brought about by three various concoctions of hydrolyzed protein(.3g/kg) by itself or the same amount of protein with a low amount of carbohydrate(.15g/kg) or a high amount of carbohydrate(.6g/kg). Ten health fit males were used and underwent a resistance trained protocol.  Subjects ingested a standardized meal prior to testing and logged their dietary intake for 48h prior.  Following exercise, subjects than received their drinks every 30mins, to reach the .3k/kg of hydrolyzed protein per hour. The outcome showed, there was NO difference in muscle protein synthesis between the groups. The researchers stated in conclusion “As such, our data indicate that carbohydrate coingestion is not required to maximize the postexercise muscle protein synthetic response when ample protein is being administered”  
There are a couple key points that should be made about this study. One is, that unlike some other post-workout studies, higher more real world relevant amounts of protein were used .3g/kg, which would be 27grams for a 90kg(198lbs) man.  Even in the carb groups, that had much higher insulin levels, muscle protein synthesis was not increased. The protein used, was NOT a regular intact whey protein,it was the highly hydrolyzed casein protein, peptopro™ . This protein contains 70-80% rapidly absorbed di-and tripeptides. Di-and tripeptides have been shown to increase insulin and this small increase in insulin could have been all that is needed to enhance protein synthesis, without the need of carbohydrates. This is just a speculation though and was not stated in the research. Lastly, the results of this study, should not be carried over to regular intact whey protein at this time, as mentioned before, di-and tripeptides behave differently than regular intact whey.

Koopman R, Beelen M, Stellingwerff T, Pennings B, Saris WH, Kies AK, Kuipers H, van Loon LJ.
Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis.
Am J Physiol Endocrinol Metab. 2007 Sep;293(3):E833-42. Epub 2007 Jul 3.

By: ATHLETIC EDGE NUTRITION

If you’ve ever participated in any type of endurance event before, you’ve likely heard about the carbohydrate loading strategies that many of these athletes perform in order to try and maximize their muscle glycogen levels to achieve better performance.

The thinking behind carbohydrate loading is that by first depleting the muscle glycogen levels and then loading with carbohydrates, you will really increase the amount the body is able to store, thus preventing the onset of fatigue while exercising.

But is carbohydrate loading the only way to accomplish such a goal?

This is what researchers from the Sports Science Institute of South Africa decided to look at.  They wanted to see what the effect would be if athletes were fed a higher fat diet prior to the actual carbohydrate load just before the race would be in contrast with a more typical mixed diet.

They had subjects either eat a high fat diet (65% or more calories from fat) or else a standard diet (about 30% of calories from fat) for a period of ten days before entering a three day period of a high carb loading diet (greater than 70% calories from carbohydrates).

The results of the study indicated that both groups showed similar weight, body fat, and lipid profiles and there was no change in the circulating glucose, lactate, or free fatty acids while the exercise was taking place.

The high fat diet prior to the carb load however did increase the total fat oxidation rate, thus meaning the athletes were not using as much of the stored carbohydrate during the actual event.

This then demonstrates that starting with a period of higher fat eating, then doing your carbohydrate load, could potentially be more advantageous towards keeping muscle glycogen stores fuller during prolonged exercise than using the standard higher carb
diet approach.

Reference:
Dennis, SC. (2001) High-fat diet versus habitual diet prior to carbohydrate loading: effects of exercise metabolism and cycling performance. Int J Sport Nutr Exercise Metabolism. Jun;11(2):209-25.

Branch chain amino-acids or just Leucine

In a previous entry of mine, I reviewed a study that compared the muscle protein stimulus of the essential amino acids (EAA) against a branch chain amino acid formula, that contained an equal amount of leucine compared to the EAA supplement. What that study showed, was that BCAA’s could only stimulate protein synthesis for a short time(15-30mins) and then declined rapidly, while the EAA supplement kept protein synthesis stimulated for four hours. In a nutshell, this study and other show the presence of the other EAA’s are needed to maintain the rate of muscle protein synthesis, stimulated by leucine.

The next study being reviewed looked at muscle protein synthesis(MPS) in rats and compared the rates brought about by various mixtures of amino-acids and glucose. For simplicities sake, we will just focus on the rates of MPS brought about by the leucine and glucose mixture compared to the BCAA and glucose mixture. The outcome showed there was NO difference in MPS between the two groups, with the researchers stating “the effect of the BCAAs can be attributed entirely to leucine, which had the same effect as the 3 BCAAs together, whereas isoleucine and valine had no effect”

Garlick PJ
The role of leucine in the regulation of protein metabolism
J Nutr. 2005 Jun;135(6 Suppl):1553S-6S.

BY: Athletic Edge Nutrition, The Nutrient Timing Specialists.