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From The September 2001 Issue of Nutrition Science News
ACSM Conference Unveils
Performance Enhancers
By Edmund R. Burke, Ph.D.
The search for the most current sports nutrition and supplementation information inevitably leads to the scientific laboratories where researchers test performance-enhancing nutrients. Every year, many of these scientists gather as members of the American College of Sports Medicine (ACSM) to share their discoveries. This year's conference in Baltimore drew 3,500 sports-nutrition professionals seeking the latest information to help athletes perform faster, stronger, and healthier.
The ACSM was founded in 1954 to facilitate the exchange and development of scientific information, and has grown to nearly 15,000 members in more than 50 countries. Through the years, many of the ACSM's position papers on fluid replacement, exercise, and anabolic steroids have become scripture for sports nutrition professionals.
I've selected for review the following from the conference's more than 1,950 new, unpublished studies and seminar presentations on sports nutrition and health. To access conference abstracts, log on to www.acsm.msse.org and click on "contents," then "May Supplement, 2001." The following represent five of the more interesting studies to come out of the conference.
Norandrostenediol Ineffective
Researchers at the University of Delaware determined the effects of eight weeks of supplementation with 224 mg of 19-nor-4-androstene-3, 17-dione and 120 mg of 19-nor-4-androstene-3, 17-diol (344 mg total Norandro per day) on strength and body composition in resistance-trained men.1 Subjects were randomly assigned to receive either 344 mg Norandro or placebo. Each subject participated in resistance training approximately four days per week for the duration of the study. Body composition was assessed via dual-energy absorptiometry (DEXA). Strength was measured with one maximal bench press and biceps curl. There were no significant changes in any of the parameters measured. Researchers concluded that moderate doses of various forms of androstenedione and androstenediol do not alter body composition or strength in resistance-trained men.
HMB Lowers Cholesterol, Increases Strength
Preliminary research indicates that the amino acid leucine metabolite beta hydroxy-beta-methylbutyrate (HMB) can increase strength and lean body mass.2 A meta-analysis of nine studies conducted at Iowa State University in Ames found HMB also consistently lowers low-density lipoprotein (LDL) cholesterol.3 However, it is unknown if similar results could be obtained in patients with hypercholesterolemia.
C. W. Coelho, Ph.D., at Coma Filho University in Rio de Janeiro, Brazil, designed a study to determine if HMB would benefit patients with hypercholesterolemia by decreasing LDL as well as increasing both lean body mass and muscle strength.4 Twelve men, ages 50 to 72 years, with a total cholesterol and HDL cholesterol ratio greater than 4.5, were randomly assigned in the double-blind study to receive either placebo capsules or capsules containing 3 g/day HMB for four weeks. Patients participated in an exercise training program five times a week consisting of three aerobic exercises and two resistance-training sessions. Blood samples, one repetition maximum test, and body fat and lean mass (skin-fold thickness) were measured at the beginning and end of the study. The pre- and post-test results showed significant differences. Men in the HMB group lowered their LDL from 172 mg/dL to 123 mg/dL and increased their lean mass by 6 percent (35.3 to 37.68 kg).
In addition, with HMB supplementation, strength was significantly increased in all three tested strength exercises: leg press, rear lat pull-down, and biceps curl. The placebo group showed no significant differences in LDL or lean mass but showed significant differences between pre- and post-test results for two exercises: leg press and rear lat pull-down. HMB supplementation in combination with an exercise training program provided a greater reduction in LDL and significant gains in both muscular strength and lean mass.
Co-Q10 For Weekend Warriors
Researchers have found that coenzyme Q10 (Co-Q10 or ubiquinone) can lower blood pressure in hypertensive people.5 In a case study, researchers at Brooklyn College of The City University of New York tested the effect of 50 mg/day Co-Q10 on systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in a 24-year-old hypertensive man who is a recreational athlete.6 After the four-week trial, significant differences in SBP and MAP, but not DBP were found.
Researchers measured functional fitness in a one-mile walking test at weeks one and four. The subject decreased his time from 10:43 minutes to 10:21 minutes and maximum heart rate from 170 bpm to 156 bpm. Co-Q10 may be effective for recreational athletes who want to control systolic and mean arterial blood pressure. Future studies should explore whether Co-Q10's mechanism of action for reducing blood pressure is via normalizing peripheral resistance or cardiac regulation.
Cordyceps Metabolizes Fat
Researchers have shown that using the medicinal mushroom Cordyceps sinensis (Cs-4 CordyMax) for six weeks results in peak oxygen uptake and anaerobic threshold in older humans.7 Researchers at the Fit Stop Human Performance Laboratory in Encinitas, Calif., conducted a follow-up randomized, double-blind, six-week study to determine the effect of daily supplementation with 4.5 g/day Cs-4 CordyMax.8 Researchers studied highly fit athletes for their oxygen uptake, anaerobic threshold, and heart rate during maximal and submaximal treadmill exercise. Thirty male adventure racers and multisport endurance athletes were assigned to either Cs-4 CordyMax or a placebo control group. Before and after the supplementation period, each subject performed a maximal treadmill test using a running protocol, followed the next day by a submaximal running test (60 minutes at 70 percent VO2 peak).
Results showed that the supplement prevented increased body weight during training, reduced submaximal heart rate and blood lactate during exercise, and enhanced fat metabolism, thereby sparing muscle glycogen expenditure during prolonged exercise compared to placebo. These findings suggest that the Cs-4 CordyMax supplementation may have positive circulatory and metabolic effects during submaximal exercise in endurance-conditioned athletes.
D-pinitol Aids Creatine Retention
Reseachers have reported that creatine hyperaccumulation in muscle is insulin dependent. Since the naturally occurring glycan D-pinitol has been reported to possess insulin-like effects, researchers at Arkansas State University in Jonesboro examined whether D-pinitol (Inzitol) influences whole-body creatine retention.9
Twenty men with no history of supplementation gave urine samples for four days. After one control day, subjects ingested in a single-blind manner either a placebo containing 5 g dextrose four times/day, 5 g creatine monohydrate four times/day, creatine with low-dose pinitol (5 g creatine four times/day, 0.5 g pinitol twice/day), or creatine with high-dose pinitol (5 g creatine, 0.5 g pinitol four times/day) for three days. Additionally, another group took 0.5 g pinitol twice/day for five days followed by 5 g creatine four times/day and 0.5 g pinitol twice/day for three days. Creatine retention was estimated by subtracting total urinary creatine excretion from total creatine intake during the three-day period.
Results revealed that cumulative creatine retention was significantly greater in the low-dose pinitol and prepinitol-loading groups. Researchers extrapolated a significantly greater percentage of creatine retention in the low-dose and preloading pinitol groups (creatine monohydrate equaled 61 percent; low-dose pinitol equaled 83 percent; high-dose pinitol equaled 61 percent; pre-loading pinitol equaled 78 percent). These preliminary findings suggest that ingesting D-pinitol during creatine loading or prior to and during creatine loading may augment whole-body creatine retention.
Edmund R. Burke, Ph.D., is an exercise physiologist at the University of Colorado, Colorado Springs.
References
1. Falk D, et al. Moderate doses of norandrostenedione and norandriostenediol supplementation have no effect on body composition and strength in resistance-trained men. www.acsm-msse.org, abstract 1910.
2. Slater GJ, Jenkins D. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation and the promotion of muscle growth and strength. Sports Med 2000 Aug;30(2):105-16.
3. Nissen S, et al. Beta hydroxy-beta-methylbutyrate (HMB) supplementation in humans is safe and may decrease cardiovascular risk factors. J Nutr 2000 Aug;130(8):1937-45.
4. Coelho CW, et al. Effects of perceived exertion on quadriceps femoris torque output. www.acsm-msse.org, abstract 484.
5. Langsjoen H, et al. Usefulness of coenzyme Q10 in clinical cardiology: a long-term study. Mol Aspects Med 1994;15(suppl):S16575.
6. Sgherza AL, et al. The effect of CoQ10 on blood pressure in a hypertensive recreational athlete: a case study. www.acsm-msse.org, abstract 925.
7. 46th annual meeting of the American College of Sports Medicine. Seattle, Washington, USA. June 2-5, 1999. Abstracts. Med Sci Sports Exerc 1999 May.
8. Nicodemus KJ, et al. Supplementation with cordyceps Cs-4 fermentation product promotes fat metabolism during prolonged exercise. www.acsm-msse-org, abstract 928.
9. Rasmussen C, et al. Influence of D-pinitol on whole body creatine retention. www.acsm-msse-org, abstract 1147.
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