The purpose of this study was to determine whether methoxyisoflavone, 20-hydroxyecdysone, or sulfo-polysaccharide supplementation affects muscle mass, training adaptations, or markers of muscle growth and/or breakdown in resistance-trained males. The major finding of this study was that dietary supplementation of commercially available supplements containing methoxyisoflavone, ecdysterone, and sulfopolysaccharide (CSP3) did not significantly affect anabolic or catabolic responses to resistance training, body composition, or training adaptations. These findings do not support contentions that methoxyisoflavone, ecdysterone, and sulfopolysaccharide (CSP3) supplementation during resistance training enhance gains in strength, power or muscle mass.
Isoflavones are naturally occurring non-steroidal phytoestrogens found primarily in soy beans [1
]. 5-methyl-7-methoxy-isoflavone is believed to play a role in increased protein synthesis and muscle accretion. They are also believed to reduce body fat, lower cholesterol levels, promote endurance, increase vitality, and the body's ability to use oxygen. The primary foundation of these beliefs have been data described in a U.S. patent in the early 1970's [16
]. Feurer et al [16
] reported lower cortisol levels, increased protein synthesis, and improved overall recovery from exercise as a result of isoflavone supplementation in animals. Preliminary results from a study only available in abstract form [18
] evaluated the effects of 5-methyl-7-methoxyisoflavone supplementation (800 mg/day for 8-weeks) on training adaptations in 14 resistance-trained men. Inclendon et al[18
] reported 5-methyl-7-methoxyisoflavone supplementation did not significantly affect changes in body weight, body mass index, bone mineral content, or isokinetic peak force between groups. However, DEXA determined FFM increased by 1.3 kg in the methoxyisoflavone group while being unchanged (0.1 kg) in the placebo group resulting in a significant reduction in body fat percent. Results of the present study do not support the purported ergogenic value of 5-methyl-7-methoxyisoflavone supplementation in resistance-trained males.
Ecdysterones have also been recently purported to enhance training adaptations during resistance training. In support of this contention, research in animal models has suggested that ecdysterone supplementation can promote anabolic activity in skeletal muscle [5
], as well as increase cell proliferation and growth, which can lead to an increase in muscle mass [6
]. Russian scientists' have been evaluating the effects of ecdysterones for years. Oral administration of Leuza (herbal ecdysterone) in male albino mice caused a statistically significant increase in the time of running [19
]. After 20 days of supplementation, there was a significant increase in work capacity. The same researchers evaluated the effects of 20-day administration of ectisten-containing tincture of leuzea and leveton on humoral immunity of track and field runners for distances of 5,000 and 10,000 m. Intensive cyclic physical activity induced significant decrease of IgG and IgA in blood serum of the athletes. These researchers concluded that both supplements contributed to restoration of the lowered IgG and IgA, while the working capacity of the athletes grew by 10 to 15% [20
]. Furthermore, Chermnykh et al [5
] compared beta-ecdysterone with dianabol which is an extremely powerful anabolic steroid, suggesting both beta-ecdysterone and dianabol increased the size and strength of the muscles. These researchers concluded that ecdysterone had a greater anabolic action on the contractile proteins of the skeletal muscles than dianabol.
The most often cited scientific study on ecdysterone was published in Scientific Sports Bulletin
by Simakin [21
]. This study sought to determine the effect of ecdysterone on muscle tissue mass and fat mass, while testing for hormonal changes in the subjects. Seventy-eight highly trained male and female athletes served as subjects in one of three experimental groups: protein, protein and ecdysterone, and placebo. Those consuming just protein, showed only a slight increase in muscle mass for the 10 day period of time, while the placebo group experienced a slight reduction in lean muscle. The addition of ecdysterone in conjunction with protein intake resulted in a 6–7% increase in lean muscle tissue with nearly a 10% reduction in fat. Finally, Gadzhieva and colleagues [22
] reported that 3-weeks of Ekdisten, leveton, and Prime Plus (combination of Ekdisten and pure protein) supplementation during training increased skinfold determined muscle mass, decreased fat mass, and increased total work during training. Additionally, Ekdisten and Prime Plus supplementation appeared to promote the greatest gains during training. These studies found that ecdysterone might increase work capacity, decrease fat mass, and increase lean muscle mass.
Results of the present study contrast these reports. In this regard, ecdysterone supplementation had no significant effects on body mass, body composition, strength, or markers of anabolic and catabolic status. Since most of the previous studies reporting positive effects of ecdysterones have been reported in obscure journals with limited details available to evaluate the experimental design and quality of the research, it is difficult to compare results. Nevertheless, present findings do not support the purported ergogenic benefit of ecdysterone supplementation in resistance-trained males.
The last supplement investigated was sulfo-polysaccharide, which is advertised to bind to myostatin and inhibit its activity in skeletal muscle. Of the three supplements examined in our study, sulfo-polysaccharide supplementation has the best theoretical rationale as a potential ergogenic aid. Myostatin is a cytokine that works by inhibiting the proliferation of satellite cells and the differentiation of myoblasts [10
]. Research in mice has shown that binding or blocking myostatin results in dramatic increases in body mass, muscle mass, muscle size, and strength following administration of antibodies that are specific for the cytokine myostatin [11
]. To date, only one human study has administered sulfo-polysaccharides in conjunction with a resistance training protocol [13
]. This study examined 12-weeks of resistance training and cystoseira canariensis supplementation on serum levels of myostatin and muscle strength and body composition in twenty-two untrained males. Training consisted of three days per week using 3 sets of 6 to 8 repetitions at 85–90% 1 RM. The researchers concluded that 12-weeks of heavy resistance training and 1200 mg/d of cystoseira canariensis supplementation appeared to be ineffective at inhibiting serum myostatin and increasing muscle strength and mass or decreasing fat mass. The explanation for the dramatic effects in animals while no observed effects in humans probably lies in the fact that myostatin specific antibodies were used in the animal model, while human models use sulfo-polysaccharides that are only advertised to bind to myostatin. Results of this study support this prior report in that CSP3 supplementation had no significant effects on body composition, training adaptations, or markers of anabolic/catabolic status in resistance-trained men.
Based on the results of this study, we conclude that supplementation of methoxyisoflavone, ecdysterone, and/or sulfo-polysaccharides (CSP3) do not have any affect on training adaptations and/or anabolic/catabolic status in resistance-trained subjects. These findings contrast marketed claims that these nutrients promote muscle accretion, increase anabolic status, decrease adipose tissue, and/or enhance training adaptations in resistance-trained athletes. These data are representative of a specific training protocol as well as specific prescribed doses of the experimental supplements, but the doses used represent the recommended amount found in these types of supplements.
Change in bench press and leg press 1-repetition maximum levels (mean ± SD) between groups following 8 weeks of resistance training and supplementation.
Change in Wingate sprint performance (mean ± SD) between groups following 8 weeks of resistance training and supplementation.