2009 Studies & Research Blog

For  five straight years now, the research on beta-alanine continues to pile up. We’ve seen studies looking at everything from resistance training performance, high intensity interval training, track and field sprinting, swimming performance and much more. At this point beta-alanine is considered one of, if not the most versatile ergogenic aids, impacting both anaerobic and aerobic performance and increasing lean body mass(LBM). The latest study is a highly sport specific cycling study, most relevant to competitive cyclists.  Twenty one well trained cyclists partook in this double blind placebo controlled study lasting  eight weeks. The performance tests utilized in this study, were set up to to mimic the sprint in a final stages of a cycling event. Pretesting performance data was measured and compared to posttesting in both the beta-alanine and placebo group. Eight weeks later, when posttesting took place, the researchers found, there was a significantly increased in power output during the final sprint in subjects ingesting beta-alanine, where as the placebo group slightly decreased when comparing pretested VS post testing.  For a competitive cyclist this could make a tremendous difference in their performance at the end stage of the event, making a big difference in their overall placing. The results of this study, likely cross over to other competitive sports like  cross country skiing, track and field and other events, where there is an all out sprint at the end of the event.

Van Thienen R, Van Proeyen K, Vanden Eynde B, Puype J, Lefere T, Hespel P.
Beta-alanine improves sprint performance in endurance cycling.
Med Sci Sports Exerc. 2009 Apr;41(4):898-903.

By:ATHLETIC EDGE NUTRITION

There are many medical diagnoses that patients don’t want to hear, but an increasingly common and serious one is that of hypertension, or high blood pressure.  High blood pressure affects millions world wide, and the severity of the condition cannot be understated. Despite how widespread and alarming high blood pressure can be, though, not many people understand what hypertension is, or even what normal blood pressure should be.

Blood pressure readings consist of two numbers: systolic pressure and diastolic pressure.  Systolic blood pressure is the top number in a blood pressure reading, and is a measurement of the pressure within blood vessels while your heart is beating. Ideally, systolic blood pressure should be around 120mmHg.  The bottom number, diastolic blood pressure, refers to the pressure within blood vessels when the heart is at rest.  A very healthy individual would have a diastolic blood pressure reading of about 80mmHg, meaning that the total blood pressure reading would be 120/80 mmHg.

High blood pressure, or hypertension, is defined as when systolic blood pressure is consistently higher than 140mmHg and diastolic blood pressure is more than 90mmHg.  And while hypertension is easily defined, getting to the root of why one has the condition can be more difficult.  High blood pressure is induced by a variety of issues, such as excess salt in the body, improperly functioning kidneys, nervous system, or blood vessels.  In addition, smoking, obesity, diabetes, alcohol abuse and even anxiety and stress are risk factors for hypertension.

Of course, hypertension is far from a death sentence, and there are many treatment options available.  Most of these rely on medications such as beta-blockers, ACE inhibitors, diuretics and calcium channel blockers.  However, these medicines may cause issues of their own and are often quite expensive.  Luckily, brand new research published in the November issue of the Journal of Strength and Conditioning Research indicates there is an alternative - one that will complement your health and won’t cost you a thing.

This new research compared the effects of different forms of exercise on adults who were known to be hypertensive.  Specifically, researchers studied changes in blood pressure after a 20 minute control session, a 20-minute resistance training session, and 20 minutes of treadmill running.  While both the treadmill running and resistance training resulted in improvements in blood pressure, the resistance training proved to be superior.

Just 20 minutes of resistance training resulted in a 12.6mmHg reduction in systolic blood pressure and a 9mmHg decrease in diastolic blood pressure.  The researchers were also pleased to find that the reductions were not short lived; even seven hours after exercise, blood pressure was still reduced as a result of the exercise.  According to this data, resistance training seems to be a safe, effective way to lower blood pressure significantly.

But which exercises should be used? The researchers employed a circuit training protocol, and used such exercises as the bench press, pull up, biceps curl, leg press, hip adduction and abduction and trunk extension.  Based on this data, it seems that a wide variety of resistance exercises can be used to battle blood pressure without the expense or inconvenience of medicine.

SOURCE:

1. Mota, Marcio R., et al. Effects of Treadmill Running and Resistance Exercises on Lowering Blood Pressure During the Daily Work of Hypertensive Subjects. Journal of Strength and Conditioning Research, 2009; 23(8): 2331-2338

You’ve likely read about it time and time again – if you’re on a fat loss diet, you should increase your meal frequency because this will help you burn more calories and lose weight easier.  Often, this causes people to become quite obsessive-compulsive when it comes to planning their schedule and if something throws a kink their way and they’re 30 minutes past due on their three-hour-between-meals design, stress levels shoot through the roof.

It may be time to learn to relax that thinking.

In a study published by the British Journal of Nutrition, researchers looked at the impacts meal frequency had on weight loss when comparing two different meal frequency groups taking in the same amount of daily calories.

Other reports have suggested that there is a positive associate between meal frequency as it relates to appetite control and potential even gut peptides, so the researchers wanted to assess this for themselves.

They had a group of subjects randomized into two treatment groups. The first treatment group was the high meal frequency group and had three meals plus three snacks each day.  The second treatment group’s calorie intake was divided between only three meals, however both groups maintaining the same calorie deficit over the day for an eight week long period.

After the eight weeks were up, it was noted that there was an overall decrease of 4.7% in body weight and that both groups demonstrated similar decreases in fat mass, and BMI changes.  It was also seen that there were no differences between the two frequency groups in relation to appetite measurements or gut peptides, thus disproving that meal frequency is a major underlying factor of success on a weight loss program.

So the take-home message from this study is don’t stress about meal frequency.  If eating six or seven times a day makes your life miserable and makes you want to call it quits on your diet, change that. Eating that often will not make or break your results, but not eating the right calorie and macronutrient intake will.

Figuring out the right types of foods to eat in the right quantities is far more important for success in the battle of the bulge so that’s what you should put your efforts into.  If you personally do much better knowing food is coming every couple of hours, there’s no reason not to adopt an increased meal frequency and many do find this helps them stick with their diet better.

But if you’re not one of those people, don’t let that make you feel like you just can’t succeed.  You can – you just need to adjust the program based on your own personal preferences.

Reference:
Cameron, JD., Cyr, MJ., Doucet, E. (2009) Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8 week equi-energetic energy-restricted diet. British Journal of Nutrition. Nov 30:1-4.

Ask any nutritionist, weight-loss coach, or successful dieter - when you’re looking to drop a few pant sizes, food choice matters.  While portion control and exercise are obviously also major factors, eating the right kinds of foods can make or break your diet plan more than anything else.  You may have heard of the so-called good carbs and bad carbs, but the proper dieting decisions go far beyond just those choices.  Limiting your intake of carbohydrates as a whole can be beneficial when dieting, and shifting your intake to include higher proportions of protein and healthy (usually unsaturated) fats can boost your metabolism as well as your overall health.  Instead of cooking in butter and topping your sandwiches with mayonnaise, one should try cooking with olive oil and adding avocado or mustard to add excitement to a boring lunch.  And instead of eating ground beef or fried chicken, try some lean bison steaks or grilled chicken.

However, the answer to losing weight isn’t just as simple as swapping a few foods here and there.  To really accelerate your weight loss, you have to take advantage of the unique aspects of each particular food.  If that sounds too complicated, though don’t worry - it’s not.  Recent research has indicated that one tiny change can make a dramatic difference in your weight loss efforts.

The change - switching from eating lean meat to lean fish.  Despite the common belief that the ideal weight-loss regimen consists of copious amounts of grilled chicken and broccoli, a recent study published in the journal Nutrition, Metabolism, and Cardiovascular Diseases, found that eating fish instead of other lean protein products can result in faster weight loss.

In the study, researchers broke the pool of subjects into three groups: one that was given lean meat as a main protein source, and one that was given cod, a low-fat fish, three times weekly in place of the lean meat, and one that was given cod five times per week in place of the meat.  The participants followed this protocol as part of a strict diet for eight weeks.  Even in this short time span, researchers noticed significant differences.

According to the results, just three weekly servings of cod was enough to promote weight loss benefits, and the advantages increased with higher fish consumption.  As such, group consuming cod five times per week had the best results, losing about 3.74 more pounds than the lean meat only group.  Waist circumference and fat mass reductions were also superior in this group.

And unlike many weight-loss diets, the plan followed in this experiment did not include an insanely high amount of protein paired with very few carbohydrates.  Just 17 percent of total calories came from protein, compared to 35 percent from fat and 48 percent from carbohydrates.  This study shows that dieting doesn’t need to be extreme; as long as one makes smart choices, a balanced, reasonable diet can promote impressive weight loss.

SOURCE:

Ramel A, Jonsdottir MT, Thorsdottir I. Consumption of cod and weight loss in young overweight and obese adults on an energy reduced diet for 8-weeks. Nutrition, Metabolism, and Cardiovascular Diseases, 2009; 9(10):690-696.

Many people who are looking to maximize performance will turn to a sports drink to help them get through those duelling hour-plus sessions.  Usually a sports beverage is not recommend for time periods under about the sixty minute mark as the body, under normal circumstances, will have enough stored muscle glycogen to get through the activity provided a usual mixed diet has been followed.

When you look at the most popular sports drinks on the market, they are primarily made up of a carbohydrate solution that may or may not contain added vitamins for support.

Recently a study was published out of the Journal of Strength and Conditioning Research where researchers assed what the impact was on substituting some of the carbohydrates in these sports drinks for protein.  It is well known that protein is also a vital nutrient for the repair of muscle tissue after an exhaustive bout of exercise, so by taking in some protein in the beverage, you would kick start this process.

But what would swapping carbs for protein do to the energy levels demonstrated during the session?

To conduct the study, the researchers had twelve male and female trained cyclists exercise on four different occasions at intensities that varied between 55 and 75% of their VO2 max for two and a half hours.  At every 20 minute mark during the workout session, they were provided with an energy drink formula that either consisted of a 4.5% carbohydrate and 1.5% protein solution, a 3% carbohydrate and 0.75% protein solution, a 6% carbohydrate solution, or a placebo.

After the exercise was completed and results were observed, it was indicated that there was no significant difference in time to exhaustion or blood parameters between the supplemental beverages.  It was noted however that those who did not use a beverage (took the placebo) did fatigue faster and had higher levels of circulating plasma free fatty acids than the control groups of the experiment.

So from this study we can conclude that using a protein and carbohydrate containing beverage during your workout sessions can be just as effective at maintaining energy levels during the workout as the pure carbohydrate beverages on the market and you’ll also get the additional benefit of providing critical amino acids to the muscle tissues.

Reference:
Bernard, JR., et al. (2009). Added Protein Maintains Efficacy of a Low-Carbohydrate Sports Drink. Journal of Strength and Conditioning Research. Nov. 17.

The amino-acid tryptophan (TRP) is a precursor to the feel good neurotransmitter serotonin. Scientists are always looking for efficient ways to boost serotonin levels and one way this can be accomplished is through elevating blood plasma levels of TRP. This very interesting study, compared tryptophan- rich alpha-lactabumin (ALAC) to hydrolyzed protein, pure tryphtophan(TRP), synthetic tryptophan-peptide and placebo, looking at blood plasma elevations in TRP and mood. ALAC would be the typical source of TRP from an intact source of protein such as whey. The amount of tryptophan in each treatment, except the placebo group was matched.  The hydrolyzed whey significantly increased plasma tryptophan(TRP)compared to the ALAC. The hydrolyzed protein effects on plasma TRP were similar to the synthetic TRP peptide and faster than the free-form tryptophan.  It only took sixty minutes after ingesting the hydrolyzed protein for mood to be improved. The researchers concluded that hydrolyzed protein maybe be more effective at increasing brain TRP levels than ALAC and even more so than pure TRP. Not stated in the research but it could be postulated, that hydrolyzed proteins, especially high in rapidly absorbed di-and tripeptides, could have been the reason for more rapid absorption then slower digested intact sources or even free-form TRP. Reason being is, some research has shown short chain di-and tripeptides are absorbed faster than both intact proteins and free-form amino-acids, due to their gut transporters having a greater capacity.

Markus CR, Firk C, Gerhardt C, Kloek J, Smolders GF. Effect of different tryptophan sources on amino acids availability to the brain and mood in healthy volunteers. Psychopharmacology (Berl). 2008 Nov;201(1):107-14. Epub 2008 Jul 23.

Written by: ATHLETIC EDGE NUTRITION

The human body is capable of amazing things.  From sprinting at super speed or running a marathon to pushing an incredible amount of weight during a squat or a bench pres, there seems to be no limit to what people can do if they put their minds to it.  Of course, these amazing feats of physical prowess aren’t just a result of mental focus or concentration.  In order to excel at the highest levels of competition or even just to achieve your own personal bests, attitude and mental energy are helpful, but these aspects alone won’t take you all the way to the top.

However, when combined with a high level of dedication in terms of diet and training, the sky is the limit.  Consistently paying attention to the tiniest details in your diet and training routine as well as making the correct choices in bigger matters are both required to maximize results.  It may seem slightly obsessive, but achieving one’s maximum potential in terms of optimal performance, increasing muscular size and strength, or reducing body fat and revealing a six pack takes a combination of mental drive and physical effort

And just as one single effort alone can’t optimize results on its own, one single supplement isn’t going to make the most of your training.  So while some products can have dramatic effects on their own - you’d be hard pressed to find a strength athlete that doesn’t boost protein intake through whey or another protein powder - a combination of supplements can unleash explosive advantages.  For instance, research has shown that stacking whey protein powder and branched chain amino acids (BCAAs) leads to significant gains in strength and muscle mass (1).

One lesser-known but just as potent combination is that of Conjugated Linoleic Acid (CLA) and the amino acid Arginine.  But don’t get the wrong idea - both CLA and Arginine are very effective when used by themselves; CLA is sometimes referred to a "fat-burning fat" because it has been shown to reduce body fat.  Arginine, meanwhile, is a powerful supplement that increases blood flow and widens blood vessels, allowing for superior delivery of oxygen to working muscles.

New research, though, has shown that using both of these supplements at the same time provides significant benefits.  A study from Texas A&M University compared the supplementation of Arginine with either Canola oil or CLA.  Based on the research, the advantage was clear - the CLA and Arginine group had around 30 percent less fat tissue at the end of the study than the Canola oil and Arginine group.  But that’s not all; even while reducing body fat, the CLA and Arginine combination also enabled that group to increase muscle mass (2).

This may come as a surprise, as one of the most commonly repeated mantras in fitness is that you can’t lose fat and build muscle at the same time.  This may be true if the effort is being made with just your body and mind alone; but a powerful combination of supplements such as CLA and Arginine can be a game-changer, as this research shows.

SOURCES:

1. Kerksick, C.M., et al. Journal of Strength and Conditioning Research. 20(3): 643-653, 2006.

2. Nall, Jennifer, et al. Journal of Nutrition. 139(7):1279-1285

It’s well known that one of the key aspects to managing diabetes is making sure you keep your weight within a reasonable range.  Being over weight can not only lead to the development of diabetes, but it can also make managing it more difficult as well.

As many of those who are either at risk for diabetes or are concerned about the development of diabetes put themselves on a weight loss diet, many will have to utilize this calorie restriction intake for quite a lengthy period of time to get to their intended goal weight.

In addition to managing diabetes, long term calorie restriction has also been noted to be beneficial for increasing the lifespan so many individuals who do not even have a weight problem to start with are also adopting such a diet to hopefully enjoy those benefits.

Before doing so though, it’s important to bear in mind what long term calorie restriction does to insulin sensitivity.

In a study that was conducted out of the Division of Geriatrics and Nutritional Science and Center for Human Nutrition in Washington, researchers assed the effects of long-term calorie restriction on glucose tolerance and insulin sensitivity by measuring body composition, glucose and insulin responses to an oral glucose tolerance test, and serum adipokines in 28 volunteers who had been utilizing a calorie restricted diet for an average of 6.9 years (+/- 5.5).   The researchers also wanted to integrate the impact of exercise on the results of this study so they assessed those who were also performing endurance training while utilizing the calorie restriction (which is quite common again among those who are aiming to lose fat), with sedentary subjects eating the traditional western diet.

The results from the study indicated that those who were using the calorie restriction diets while exercising showed significant higher insulin sensitivity however also showed an exaggerated hyperglycaemic response to a glucose load.

What the take home message from this is then is that while calorie restriction is beneficial for losing weight and improving diabetes management from that sense, you need to be even more careful when do you have a higher carbohydrate meal because the impact on your blood glucose could be overly exaggerated compared to if you were not using a calorie restriction diet over the long term.

So keep this in mind.  Learning how your body responds to different diet protocols is important for not only feeling well but also managing disease conditions such as diabetes.

Holloszy, JO. (2009). Effect of long-term calorie restriction and endurance exercise on glucose tolerance, insulin action, and adipokine production.  Age (Dordr). Nov 11.

Any student-athlete, weekend warrior, or family man or woman with a penchant for fitness knows this simple fact - sometimes, exercise and a busy lifestyle don’t seem to mix.  Far from a match made in heaven, the pairing of seemingly endless obligations and the pursuit of fitness goals can make for a hectic schedule.  But out of this chaos is born a powerful tool - efficiency.  Whether you’re working out on lunch or employing supersets, finding ways to kill the proverbial two birds with one dumbbell is a great solution.

So if this concept of efficiency works in terms of training, shouldn’t it be applicable to supplementation as well?  In some cases, such as the use of Yohimbe, the answer is an emphatic "yes."  So what makes yohimbe efficient?  The fact that this one powerful supplement can have so many powerful effects that will help you reach your goals quicker than ever before.  But this isn’t some synthetic, so-called super-supplement.  Yohimbe is natural, derived from the bark of a tree.  Like many other plant-based compounds, Yohimbe has been shown in some studies to have antioxidant properties, meaning that it can help prevent against oxidative damage from free radicals.  This is particularly relevant to active individuals, as exercise does lead to increases in free radicals.

But that’s just the tip of the iceberg.  Research has also shown Yohimbe to be a powerful weapon in one’s fat loss arsenal, as it can "lower the respiratory quotient during and following exercise, thus promoting fat loss," but without excessive elevation of heart rate or blood pressure, unlike some other fat-burning products.  Scientific study has also indicated that Yohimbe may also have synergistic effects with other fat loss supplements and could improve the fat-burning response in resistant individuals, such as the elderly (1).

Futhermore, Yohimbe also acts as a vasodilator, or a compound that expands blood vessels.  This means it can reduce the likelihood of high blood pressure and improve the delivery of nutrients to working muscles, as well as facilitate easier removal of waste products, such as lactic acid.  As a result, you’ll be able to get more sets done in less time with improved recovery and power through HIIT sessions with relative ease.

And Yohimbe’s effects aren’t just limited to the gym; Yohimbe has also been shown to have potent effects on libido, and the vasodilating properties have been shown to improve sexual function (2).

As you can see, Yohimbe is a hard-working, efficient supplement, addressing a broad spectrum of physical demands and improving many aspects of one’s life.  So if you’re all about efficiency, why not add a supplement to your arsenal that will complement your efforts?

SOURCES:

1. McCarty, Mark F. Pre-exercise administration of yohimbine may enhance the efficacy of exercise training as a fat loss strategy by boosting lipolysis. Medical Hypothesis, 2002; 58(6): 491-495.

2. Hollander, Eric; McCarley, Allison. Yohimbine treatment of sexual side effects induced by serotonin reuptake blockers. Journal of Clinical Psychiatry, 1992; 53(6): 207-209.

While you will always get some people who are heavily involved in their weight training thinking they need extreme volumes of protein to build muscle mass, there are other people who still struggle to get in the minimums.  Many have heard that they require one gram per pound of body weight and shun this off as being too high because they have read that the Dietary Reference Intake recommendations are set much lower at 0.66 to 0.8 kg/day.  

For the average 150 pound person, this works out to a measly 45 to 55 grams per day.  They take that as their guide though because it’s backed by the ‘DRI’.

Recently a review was conducted by the research institute in Toronto in conjunction with the Food and Nutritional Sciences department of the University of Alberta to assess the validity of this information.

The researchers noted that traditionally the total protein requirements in adult humans were based using nitrogen balance using a single linear regression analysis.  These researchers however re-analyzed the existing nitrogen balance studies using a two-phase linear regression analysis instead and obtained from their findings a safe protein requirement of between 0.91 and 0.99 grams per kilogram per day.  

The researchers stated that the two-phase linear regression analysis is considered to be more appropriate of a measure when applies to humans and also developed an alternative method for assessing protein requirements by using the amino acid oxidation technique.

From this technique they arrived at safe reference intakes of 0.93 to 1.2 grams per kilogram per day, which as you can clearly see are much higher than the previous recommendations.

So from this we can conclude that before you set your protein intakes to the standard DRI, you may want to rethink that.  There is certainly no harm in bringing them higher and in almost all cases, you will see positive benefits from doing so. With the wide variety of protein-based supplements available today, there is no reason to not meet your protein requirements and maximize your ability to build lean muscle tissue.

Reference:
Ball, RO. Et al. (2009). Evidence that protein requirements have been significantly underestimated. Curr Opin Clin Nutr Metab Care. Oct 16.

f you spend enough time around the world of fitness, nutrition, and supplementation, you’ll realize that absolutely nothing is ever written in stone. Despite the fact that something may be accepted as fact one day, debate may rage over the concept the next. Some of this is due to the fact that the activities and interests of athletes and average consumers vary widely from era to era. This contributes to alterations in the way diets and supplements are recommended and used. In addition, different activities may necessitate new combinations of techniques and supplements, which often produce unexpected results.

Another reason for the fluctuations in the fitness world is the fact that even though many techniques and recommendations are considered to be "established," studies in this field are all relatively new. Intense scientific scrutiny of exercise science, physiology and supplementation are recent phenomena in the grand scheme of human history. So even if a substance or technique has "proven" effects, a newer study may emerge and offer completely different results. That doesn’t discount the earlier research, though; it just indicates how quickly the fitness world can evolve.

Of course, not every new study debunks an old one, and not every recommendation will be refuted at some point. Some new research confirms what is already known, adding an extra degree of legitimacy to supplement claims. And some studies may even find new, unexpected benefits and uses for nutrients and supplements. In some cases, this kind of research can take a supplement that was thought to be merely moderately useful and elevate it into a veritable "super-supplement" in many people’s minds. If the new uses of a supplement aren’t widely known, though, it effectively becomes a secret weapon for those in the know.

Take, for example, melatonin. Up until this year, melatonin was known solely as a superb sleep aid and calming agent. However, two major studies have indicated that isn’t all this supplement can do. The first study indicated that melatonin could be useful in gaining mass or leaning out, as taking melatonin before a cardiovascular training session increased growth hormone release (1). While GH is widely known to aid in anabolism, it also induces muscles to burn fat, making it effective in two fronts in the war against an average physique.

And if that’s not enough to make melatonin a staple in your regimen, consider this. Melatonin is a powerful antioxidant, and a study found that supplementation of melatonin led to a reduction in the aging of brain cells. Usually, the functioning of the mitochondria (energy production units) of cells decreases with age. However, melatonin supplementation helped to reduce the rate of degeneration (2).

As these studies show, melatonin is nothing short of a super supplement. With a diverse array of advantages, there’s really no reason not to be using it.

SOURCES:

1. Meeking, DR, et al. Exercise-induced GH secretion is enhanced by the oral ingestion of melatonin in healthy adult male subjects. European Journal of Endocrinology, 1999; 141(1): 22-26

2. Carretero, Miguel, et al. Long-term melatonin administration protects brain mitochondria from aging. Journal of Pineal Research, 2009; 47(2): 192-200

Performing physical training on a regular basis is one of the best ways to go about losing body fat and improving your overall health including the metabolic rate that is seen in the body.  There has been a number of research studies conducted that demonstrate that those who are performing sprint interval sessions show greater metabolic boosts compared with those who are doing straight cardio workouts, often making this the choice of workout for many.

Before jumping strictly on the interval bandwagon however, you may want to consider a few of the benefits you’ll see from aerobic training as well.

Recently researchers from the University of Texas Medical Branch assessed what impact lower intensity cardio training had on the fatty acid utilization of trained and untrained men.

They recorded whole body lipid kinetics, looking at the rates of glycerol and free fatty acid appearance in the plasma as well as lipid oxidation through indirect calorimetery before, during, and after exercise was completed.

The results of the study indicated that the lipolytic response to 4 hours of exercise was similar in both trained and untrained men, however the mean triglyceride oxidation was greater during exercise in the trained subjects compared to the untrained group.

It was also seen that during recovery, glycerol and FFA Ra values were decreased more rapidly in trained men, showing that those who were already endurance trained show a greater reliance on fat as fuel during low-intensity exercise and also, their lipid kinetics return to baseline more rapidly in trained men than in untrained subjects.

From this research then we can conclude that endurance training does help the body get better at utilizing fatty acids as fuel and you will see enhanced glycogen sparing during lower intensity exercise, which can potentially come in helpful for those who are involved in both endurance and strength and power activity.

Reference:
Coyle, EF, Klein, S. & Wolfe, RR. (1994). Fat metabolism during low-intensity exercise in endurance-trained and untrained men.  Am J Physiology. Dec;267(6 Pt 1): E934-40.