John Berardi - ACSM 2004 (Text Version)

A Review of the 2004 ACSM Conference; Part 1
By Dr John M Berardi, CSCS
First published at www.t-nation.com, July 27, 2004

Move over Indy 500, here comes the ACSM! This year at the American College of Sports Medicine's annual blowout, over 5000 scientists and students flooded into Indianapolis to peruse some 2500 research abstracts and related research presentations. (Oh yeah, it was a party all right.)

In this two part article, I’ll share some of the more interesting and relevant presentations with you. In Part I, I’ll cover the interesting nutrition and supplement studies (would you have expected anything less?) while in the second part I’ll cover damn near everything else. Gentlemen, start your engines.

Interesting Nutrition and Supplement Studies

1) Topic: Workout Nutrition and Hockey
Authors: Brianne Olson and colleagues from St. Cloud University
Abstract # 0121

Without a doubt, the hottest thing in sports nutrition right now is workout nutrition. Finally, researchers and coaches are embracing the use of pre, during, and post-workout nutrition.

This study lends further evidence to the utility of this approach as five university hockey players ingested either an 8% solution of carbohydrate and protein (C+P; 1000ml containing about 320kcal) or a placebo drink during one of two practices. During the practices in which the C+P drink was ingested, skating speed (measured by the time to complete a skating course), shot accuracy, and reaction time were improved by between 8 and 12% vs. the placebo condition.

This is, without a doubt, yet another reason for athletes to ingest some carbohydrate and protein during exercise. If you're a Surge fan, sipping half a serving during your workout will do the trick.

2) Topic: Glucose Oxidation and Endurance Exercise
Authors: Roy Jentjens and colleagues at the University of Birmingham
Abstract # 0151

Carbohydrate supplementation during endurance exercise has been shown to delay fatigue and improve performance. However, due to limitations in the intestinal absorption of carbohydrates, it appears that the rate of exogenous carbohydrate oxidation doesn’t exceed 1g/min when a single carb source is used. Since sucrose, glucose, and fructose may be absorbed (wholly or in part) by different intestinal transport mechanisms, the authors of this study speculated that a supplement containing glucose, fructose, and sucrose would increase the peak oxidation rate of carbohydrate during endurance exercise.

In the study, eight endurance trained men cycled for 150 minutes while receiving a solution of either 2.4g/min of glucose, 1.2g/min of glucose + 0.6g/min of fructose + 0.6g/min of sucrose, or water. In the end, exogenous carbohydrate oxidation rates were 1.18g/min in the glucose trial compared with 1.70g/min in the glucose+fructose+sucrose trial. This increase in exogenous carbohydrate oxidation was matched by a glycogen-sparing reduction in endogenous glucose oxidation.

So, endurance athletes, listen up. It’s wise to add a few different types of carbs to your carbohydrate electrolyte solution in order to spare muscle glycogen and perform at a high level.

3) Topic: Low Glycemic Carbs and Recovery
Authors: Emma Stevenson and colleagues from Loughborough University
Abstract # 0157

It’s no surprise that high GI carbs ingested before exercise may, because of the rise in insulin concentration that accompanies a high GI meal, suppress fat oxidation. This can cause an increased reliance on carbohydrate energy during exercise and deplete carbohydrate reserves more quickly.

In this study, researchers fed subjects low GI meals and high GI meals 24 hours after an exhausting exercise bout. The nine male subjects ran for 90 minutes and immediately after ingested either a low GI diet or high GI diet for 24 hours. After the 24 hour recovery period, they performed a run to exhaustion at 70% VO2max.

Subjects eating the low GI diet performed better (+11 seconds in the time to exhaustion trial) and burned more fat than subjects eating the high GI diet leading up to this second bout of exercise. In the end, it appears that a chronic low GI diet offers advantages in endurance athletes.

I might add the caveat that endurance athletes still need their high GI carbs during and immediately after training in order to resynthesize glycogen quickly before getting back to those low GI meals.

4) Topic: Post-Workout Nutrition
Authors: John Berardi and colleagues from the University of Western Ontario
Abstract # 0286

I’ve been preaching the benefits of a liquid carb/protein drink for recovery for the last three years. Finally, I’m sharing my data with the world. At three conferences this summer I’ll be presenting a series of studies we’ve undertaken to examine the recovery effects of post-workout carb/protein drinks.

In this study, I traveled down to Yale University to collaborate with the excellent folks at the department of diagnostic radiology in order to determine whether carb/protein supplementation (when compared to carbs alone) could improve muscle glycogen content six hours after a cycling time trial. We found that carb/protein supplements increased muscle glycogen content of the thigh by 22% vs. carbohydrate alone. This measurement was taken six hours after an intense cycling time trial lasting one hour.

So, if you’re an endurance athlete and want to keep up with my clients, you’d better be drinking a carb/protein drink like Surge immediately after your workout.

5) Topic: Post-Workout Nutrition
Authors: Joseph Hartman and colleagues from McMaster University
Abstract # 0287

There's much debate about the best type of protein for improving muscle mass.

In this study, 34 subjects weight trained five times per week for a total of twelve weeks. Immediately after exercise, subjects ingested a skim milk beverage, an isoenergetic soy drink or a carbohydrate placebo while the effects of the training and supplementation were measured. Although statistically, there were no differences in the amounts of body mass, lean mass and muscle strength gained, it appeared that if more subjects were tested and responded similarly, the milk group would've performed better than the soy group and the soy group better than the carbohydrate group (the milk group gained 3.3kg of lean mass, the soy group gained 2.7kg of lean mass and the control group gained 2.2kg of lean mass).

In the end, although something like Surge is still the best post-workout drink, stop emailing me to ask what you should do if you can’t afford it! This study tells you to just drink skim milk.

6) Topic: Post-Workout Nutrition
Authors: Melinda Millard-Stafford and colleagues from the Georgia Institute of Technology
Abstract # 0290

This study also tested the effects of a carb/protein drink on exercise performance.

In this study, eight runners completed a 90 minute run and then a treadmill run to exhaustion at 90% VO2max. For two hours after, subjects ingested a 6% carb drink, an 8% carb, 2% protein drink and a 10% carb drink. Two hours later, subjects repeated the treadmill run to exhaustion. Again, after 24 hours of recovery, subjects returned to the lab and a 5km time trial was performed. Using this interesting design, there seemed to be no performance differences between the three treatment conditions. However, in subjects ingesting the carb/protein drink, muscle soreness was lower 24 hours after exercise.

This decrease in soreness with carb/protein is consistent with previously published data in military recruits and with soon-to-be published data from our laboratory (in weight trainers).

7) Topic: Blood Electrolytes, Sodium, and NFL Preseason
Authors: Sandra Fowkes Godek and colleagues at West Chester University
Abstract # 0371

During NFL pre-season training, two-a-day practices in the heat have produced some disastrous results with frequent reports of dehydration and even death. But don’t let the media fool ya. It’s not always the drugs that are to blame. Rather, it’s often simply a case of not enough attention to detail, like fluid and electrolyte balance.

In this study, NFL players were tested for fluid and electrolyte balance during camp. By the third day of camp, blood sodium concentrations fell compared to baseline. Also, by day eleven, blood magnesium concentrations fell. On the other hand, by day five, blood potassium concentrations rose.

Although these changes are cause for concern at first glance, they're especially alarming when considering that these players were dehydrated. Dehydration reduces plasma fluid volume, increasing concentrations of most minerals (concentration is simply the amount of mineral/plasma volume). So in the case of the reductions in sodium and magnesium concentrations, the absolute amounts of sodium and magnesium in the blood must have fallen precipitously.

In the end, pre-season football players would benefit from a systematic rehydration regimen that included both sodium and magnesium supplementation.

8) Topic: Sodium Loading and Exercise in Heat
Authors: Stacy Sims and colleagues at Otago University
Abstract # 0574

The ingestion of sodium with large amounts of fluid can help hydrate the body as this mineral can hold additional water and sequester it in the body.

In this study, eight male endurance athletes were given a series of low sodium solutions or high sodium solutions to drink after breakfast. These solutions were ingested leading up to a run to exhaustion in the heat. With the high sodium drinks, plasma volume was increased, as was run time to exhaustion.

While supplements like glycerol have become popular with endurance athletes, many would benefit from simple sodium loading. This conclusion is also supported by data presented in abstract #1175 in which a single high sodium drink given during endurance cycling offered similar benefits in terms of maintenance of plasma volume.

9) Topic: Carb/Protein Drinks and Recovery
Authors: Brett Romano and colleagues at James Madison University
Abstract # 0851

As discussed earlier, there are several benefits associated with the ingestion of a carb/protein drink during and after exercise.

In this study, eleven male cyclists ingested either a carb/protein drink (with a 4:1) ratio or a carb-only drink during and immediately after an exercise bout to exhaustion (70% VO2max). Then, 22 to 24 hours later, the same subjects performed another bout taken to exhaustion at 80% VO2max. While no differences in time to fatigue were observed between conditions, muscle
soreness and plasma CK concentrations were reduced in the carb/protein
condition.

As discussed earlier, carb/protein supplementation seems to reduce soreness and, potentially, muscle damage, when compared to carb-only supplementation.

10) Topic: L-Glutamine and Recovery
Authors: Tavis Piattoly and colleagues at Louisiana State University
Abstract # 0853

While it's been theorized that glutamine supplementation is beneficial for athletes, very little research has supported the idea that glutamine can help improve athletic performance or muscle mass.

In this study, twelve men involved in cycle training performed a Wingate cycle test followed by a cycling test to fatigue (70% VO2max), followed by another Wingate test. The subjects then received a glutamine plus carbohydrate drink or a carb-only drink. Six days later the subjects returned to the lab and repeated the testing protocol. The glutamine supplemented group performed better in both the time to exhaustion trial and the Wingate test, maintaining peak power in this latter test while the placebo group decreased in peak power.

It appears that while glutamine has little impact on muscle mass, it might offer some advantages in certain athletic situations.

11) Topic: Post-Marathon Recovery
Authors: Shawn Talbott from the University of Utah
Abstract # 0854

Marathon running is a damaging sport, causing large amounts of stress to the neuromuscular, hormonal and immune systems of the body.

In this study, a supplement containing BCAA, glutamine and betasitosterol was given to 14 marathon runners for 14 days following the completion of a marthon. Eleven subjects received a placebo supplement during this same time period. Runners in the supplement group had improved mood scores (according to a POMS questionnaire), fewer symptoms of cold/flu, fewer symptoms of muscle/joint pain, and were able to resume training five days earlier than the placebo group.

Sometimes supplements ain’t so bad, are they?

12) Topic: Fenugreek and Glycogen Resynthesis
Authors: Dustin Slivka and colleagues at the University of Montana
Abstract # 0855

Fenugreek extract, containing 4-hydroxyisoleucine, has been shown to stimulate insulin secretion and improve glucose uptake in muscle cells. In

this study, two groups of subjects completed a 90 minute glycogen depletion ride and then ingested two supplement drinks given two hours apart. The first group received two drinks containing 1.8g carbs/kg body mass. The other group received the same dose of carbs along with 2mg/kg of 4-hydroxyisoleucine. Muscle biopsies were taken immediately after exercise and four hours later to determine muscle glycogen content. Interestingly, although there were no differences in insulin secretion between groups, the group supplementing with 4-hydroxyisoleucine had a 63% greater rate of muscle glycogen resynthesis.

While the authors couldn’t easily explain these results, these data do demonstrate that 4-hydroxyisoleucine may improve glycogen resynthesis via an insulin-independent mechanism (assuming carbohydrate intake is adequate).

13) Topic: Collagen Hydrolysate and Joint Function
Authors: Linda Zuckley and colleagues at the Rippe Lifestyle Institute
Abstract # 1073

The most popular joint repair supplement on the market is glucosamine. However, not all patients benefit from its use.

In this study, 190 individuals with symptoms of mild arthritis in the knee received either a supplement containing collagen hydrolysate (10g), calcium (300mg) and vitamin C (60mg) or a placebo for 14 weeks. After 14 weeks of supplementation, subjects in the collagen group improved their isometric and isokinetic knee strength and total work performance compared to the placebo group.

In addition to manual therapy, a good adjunct therapy for joint trauma would include glucosamine, collagen, calcium, and vitamin C.

14) Topic: Whey or Casein and Energy Deficit
Authors: Sean Heffron and colleagues at Virginia Tech
Abstract # 1164

Certain amino acids in the blood (cysteine and glutamine) are predictive of lean tissue loss in both diseased and healthy individuals.

In this study, researchers investigated whether whey protein (cysteine and glutamine rich) can prevent losses in lean body mass when athletes are on an energy restricted diet. Twenty cyclists received 40g of whey or casein per day for three weeks. During the last four days of supplementation, subjects received a restricted energy diet. During this energy restricted period, subjects all experienced a negative nitrogen balance with no difference between groups. Although plasma cysteine levels were correlated with negative nitrogen balance, neither supplement prevented this drop in cysteine or the negative nitrogen balance that ensued.

15) Topic: Vitamin E and Oxidative Stress
Authors: Ioannis Fatouros and colleagues at Democritus University of Thrace
Abstract # 1165

Vitamin E is a potent antioxidant and is known to reduce oxidative stress. Research on elite athletes, however, is scarce.

In this study, 32 professional basketball players received one of three different intakes of Vitamin E (600IU, 1200IU and 1800IU) during preseason training. After eight weeks of supplementation, a number of markers of oxidative stress (including plasma GPX, uric acid, CK, LDH, LPO) were reduced during both rest and exercise in the moderate intake group (1200IU).

These data indicate that special attention should be paid to the Vitamin E intake of athletes training at high intensities. Vitamin supplements aren't always necessary, but in the absence of adequate dietary intake they can be useful.

16) Topic: Acid-Base Balance and Anaerobic Exercise
Authors: Ioannis Douroudos and colleagues a Democritus University of Thrace
Abstract # 1166

In a previous article of mine (Covering Your Nutritional Acids — And Bases), I discussed the benefits of eating foods that present the kidney with an alkaline load to balance out the acid loads imposed by grains and high protein foods. In this study, researchers used sodium bicarbonate to alter acid base status during anaerobic exercise.

Twenty-four men received placebo, 0.3/kg, or 0.5g/kg sodium bicarbonate for six days. Performance and acid/base status was assessed before and after Wingate testing.

From this study, it appears that sodium bicarbonate supplementation improves mean power, allows for higher lactate concentrations, and maintains blood pH during anaerobic exercise. Unfortunately, sodium bicarbonate often causes significant GI distress. Because of this potassium bicarbonate may be a better choice to avoid these problems.

17) Topic: Zinc and Metabolic Rate
Authors: Christopher Theberge and colleagues at the University of Massachusetts
Abstract # 1167

Inadequate zinc intake has been shown to decrease plasma zinc status and resting metabolic rate by affecting thyroid hormone metabolism (from T4 to the more active T3 metabolite).

In this study, one male and one female were tested during a baseline, zinc depletion (low zinc intake), and zinc repletion period (higher zinc intake). During the zinc depletion phases, resting metabolic rate decreased in both subjects. After the zinc repletion period, RMR increased back to normal levels.

These data suggest that zinc status is related to metabolic rate and that low intakes of zinc may be correlated with a depressed metabolism.

18) Topic: Raisins vs. Sports Gels
Authors: Mark Kern and colleagues from San Diego State University
Abstract # 1174

A refreshing part of this year’s conference was the fact that many investigators were looking for nutritional solutions to performance issues rather than supplement solutions. Sure, there were plenty of supplement studies, but there seemed to be an equal number of studies examining the effects of different foods in direct comparison with certain supplements.

This study is a good example as the authors compared the effects of pre-exercise raisin feedings to commercially available sports gels in cyclists.
Eight endurance trained cyclists were fed 1g carb/kg body weight (raisins or sports gels) 45 minutes prior to exercise. The exercise consisted of a 45 minute ride at 75% VO2max and then a 15 minute performance trial. In the end, performance wasn’t different between the raisin and the sports gel groups. Furthermore, it appeared that raisins subtly, but more favorably, improved metabolism.

Since raisins provide more micronutrients, provide an acid neutralizing load to the kidneys, and yield the same performance benefits as gels, they provide a cheaper alternative to sports gels.

19) Topic: Hydroxycitric Acid and Fat Utilization During Exercise
Authors: Kiwon Lim and colleagues at Konkuk University
Abstract # 1180

Since HCA has been shown to improve endurance performance in mice and men (athletes), the investigators of this study were curious as to whether it would have the same effects in untrained exercisers.

In this study, six male and female subjects ingested 250mg of HCA or placebo for five days. After supplementation, subjects exercised at 40% VO2max for one hour and then 60% VO2max until exhaustion. HCA supplementation reduced carbohydrate oxidation and increased time to exhaustion in untrained subjects, suggesting a greater reliance on fat burning during moderate intensity aerobic exercise.

20) Topic: Staying Hydrated
Authors: John Seifert and colleagues from Saint Cloud Sate University
Abstract # 1240

This study is particularly interesting given the commercial popularity of those CamelBak backpacks, once the exclusive domain of endurance cyclists but now on the backs of tourists everywhere.

In this study, 14 subjects hiked for 18 miles carrying 3L of water with either a hands-free, back mounted hydration system or bottled water. Subjects with the back mounted system drank over twice as much water, had only a slightly higher urine volume, preserved body water better, and completed the four hour hike in less time.

While this approach isn’t at all revolutionary, I report on it here because I recently discovered the joys of a back mounted system while motorcycling, camping and hiking in the American Southwest. With temperatures in the 120's on some days and lots of sweat flowing, my 2L pack was perfect for the environment. Heck, I even used my pack on the plane ride home. Those flight attendants never seem to give me enough water. After slapping on my water system, I think they got the hint.

21) Topic: High Protein Diet and Myostatin
Authors: John Koichi Nakazato and colleagues from the Nippon Sport Science University
Abstract # 1369

In rats and in humans, high protein intakes above a certain threshold don't necessarily build more muscle than lower intakes (although there may be other benefits to a higher protein diet).

In rats, this threshold is 15% protein. In this study, the authors investigated (at the molecular level) why additional protein (and amino acids) doesn't stimulate further protein synthesis. In the end they found that higher protein diets lead to a high expression of myogenin (a regulatory factor that stimulates hypertrophy). But, myostatin (a negative regulator of muscle growth) is also upregulated, preventing further hypertrophy.

If it’s possible to decrease myostatin gene expression or inactivate the myostatin protein, combining these treatments with a high protein diet would likely lead to additive or synergistic increments of muscle growth.

22) Topic: BCAA and Muscle Metabolism
Authors: Keitaro Matsumoto and colleagues at Saga Nutraceuticals Research Institute
Abstract # 1372

As discussed later in this article, protein and BCAA supplementation during exercise can shift the protein balance from negative to positive.

In this study, eight men and women performed three bouts of 20 minutes of cycling exercise at 50% of maximal work intensity. During the first ten minutes of the first cycling bout, either a BCAA (2g) and carbohydrate drink (20g) or a placebo drink (22g carbohydrate) was given. In the placebo group, skeletal muscle protein balance was negative throughout the entire exercise period. In the BCAA group, protein balance was also negative but the magnitude of the negative balance was lower, indicating that BCAA can suppress some of the protein breakdown seen during exercise. However, BCAA and carbohydrate alone are insufficient to shift the protein balance from negative to positive during exercise. That’s why you’ve gotta go with protein and carbs if preventing catabolism is your game.

23) Topic: Sodium Bicarbonate and Training Adaptations
Authors: Johann Edge and colleagues at the University of Western Australia
Abstract # 1410

As discussed earlier, sodium bicarbonate ingestion can improve acute acid/base status during anaerobic exercise. In this study, the ability of sodium bicarbonate to impact training adaptations was studied.

Sixteen women were split into two groups and supplemented with either 0.4g/kg sodium bicarbonate or 0.2g/kg sodium chloride (placebo) prior to each workout during eight weeks of training. Training consisted of 6 to 12 two-minute high intensity intervals (performed three times per week). During performance testing (after the supplement period), subjects that supplemented with sodium bicarbonate had greater improvements in total work and lactate threshold.

As with acute supplementation, chronic use of sodium bicarbonate beneficially affects performance and performance adaptations. Again, it may be better to use an alternative buffer like potassium bicarbonate since
sodium bicarbonate isn't easily tolerated in many subjects.

24) Topic: Caffeine and Leg Pain
Authors: Patrick O’Connor and colleagues at the University of Georgia
Abstract # 1513

Caffeine is well-known to improve strength and endurance performance as well as the rating of perceived exertion during exercise. In this study, twelve men cycled for 30 minutes, ingesting either 10mg caffeine per kg body mass, 5mg/kg body mass, or 0mg/kg body mass one hour prior to exercise.

Consistent with previous research, caffeine supplementation reduced leg pain in all subjects; the higher the dose, the bigger the reduction. While most people think I’m anti-caffeine, I’m only anti-caffeine during most of the day. Immediately prior to exercise, go ahead and crank the big C.

25) Topic: Vitamin C and Immune Function
Authors: Hiroshi Sasaki and colleagues at Osaka International University
Abstract # 1759

Although many researchers have speculated that Vitamin C could reduce muscle soreness and damage as a result of its antioxidant benefits, the research hasn’t always supported this notion.

In this study, twelve women received 500mg of vitamin C or placebo after a weight training workout (two sets of eight exercises). While vitamin C supplementation didn't reduce muscle soreness or CK, it did prevent the decreases in WBC and lymphocyte counts seen in the placebo group.

Vitamin C may therefore help improve global immunity, preventing the usual decreases in immune function seen after strenuous exercise.

26) Topic: CLA and Strength Training
Authors: Craig Pinkowski and colleagues at the University of Saskatchewan
Abstract # 1983

Research on the unique fatty acid CLA has been varied with animal studies showing panacea-like effects but human studies showing mixed effects for everything from fat loss to lean mass gains. Many researchers think that specific CLA isomers have different properties and that once the specific isomers are tested, results will be more easily interpreted.

In this study, 77 men and women received either 5g/day of CLA (cis-9, trans-11 and trans-10, cis-12 isomers) or placebo for seven weeks. During this time the subjects strength-trained three days per week. After the seven week training program, subjects supplementing with CLA gained more lean mass (+1.4 kg vs. +0.2kg) and lost more fat mass (-0.8kg vs. +0.4kg) than subjects taking placebo.

From this study it appears that specific isomers of CLA may offer unique benefits to strength training athletes, especially when diet isn't controlled.

27) Topic: Protein Breakdown During Exercise
Authors: Hiroshi Masao Minzuno and colleagues at the Research Unit of Esbjerg Varde Central Hospital
Abstract # 2210

It’s well known that exercise (endurance or strength) has catabolic effects. Recent research has shown that providing some protein and carbohydrate prior to or during exercise can minimize these catabolic effects and potentially shift the body toward a positive protein status during exercise.

In this study, six elderly men and women performed three bouts of 20 minutes of cycling exercise at 50% of maximal work intensity. During the first ten minutes of the first cycling bout, either a protein (10g) and carbohydrate drink (16.5g) or a placebo drink was given. In the placebo group, skeletal muscle protein balance was negative throughout the entire exercise period. However, in the protein/carb group, protein balance was positive from the second exercise bout on.

So remember, even during relatively low intensity exercise, a protein/carbohydrate drink can stave off protein breakdown.

Ok, that does it for this first part of the annual ACSM report. Tune in tomorrow, race fans, for interesting research on lifestyle, training, exercise and testing equipment, hormonal manipulations, and genetic studies!