JP2023170690A - Oral composition - Google Patents

Abstract

To provide a composition for enhancing muscle and to provide a composition for maintaining and/or improving athletic performance.SOLUTION: In the course of exploring compositions that enhance muscle, the inventors have found that Dioscorea oppositifolia or Dioscorea opposita has an effect in enhancing muscle, which led to the completion of this invention. In addition, in the course of exploring compositions that maintain and/or improve athletic performance, the inventors have found that Dioscorea oppositifolia or Dioscorea opposita has an effect in maintaining and/or improving athletic performance, which led to the completion of this invention.SELECTED DRAWING: Figure 1

Description

The present invention relates to a muscle-building composition containing wild yam. Further, the present invention provides a composition for improving athletic performance, characterized by containing wild yam.

It can be said that motor function is extremely important for living a meaningful and healthy daily life. However, in recent years, due to decreased activity in daily life, aging, lack of exercise, and inability to exercise, muscle function has decreased, such as decreased muscle mass, muscle breakdown, and muscle fatigue, and exercise performance has decreased. , the inability to live a meaningful and healthy daily life has become a problem.

Components that have a muscle-strengthening effect and compositions containing such components are desired for preventing, improving, or alleviating deterioration of muscle function such as decrease in muscle mass, muscle decomposition, and muscle fatigue. For example, steroids and growth hormone are known as compounds that have muscle-enhancing effects. However, steroids and growth hormones are known to cause serious side effects such as cardiovascular disease and liver damage, as well as increases in blood pressure and cholesterol levels. In addition, a composition prepared by hydrolyzing whey protein under specific conditions (Patent Document 1) and Dioscorea esculenta (Patent Document 2) have been reported as having a muscle-strengthening effect and being ingested orally. However, the muscle strengthening effect of whey protein confirmed in Patent Document 1 is only to recover atrophied muscles, and the effect of strengthening normal muscles has not been confirmed. In addition, since the muscle-strengthening effect of Dogedokoro is not sufficient, it was necessary to further investigate ingredients that have a muscle-strengthening effect.

Compositions containing ingredients or external ingredients that maintain and improve athletic performance are desired as a means of preventing declines in abilities such as strength, speed, and endurance during exercise, and maintaining and improving athletic performance. . For example, compositions prepared by hydrolyzing whey protein under specific conditions (Patent Document 1) and extracts of Dioscorea batatas (Non-Patent Document 1) are known to have the effect of maintaining and improving exercise performance and are ingested orally. It has been reported. However, the effect of whey protein that has been confirmed in Patent Document 1 to maintain and improve exercise performance is only due to the recovery of atrophied muscles, and the effect of maintaining and improving exercise performance by strengthening normal muscles has not been confirmed. do not have. Furthermore, since the effect of the Nagai yam extract on maintaining and improving exercise performance is not sufficient, it was necessary to further investigate components that have an effect on maintaining and improving exercise performance.

In addition, in order to live a meaningful and healthy daily life, various health foods have been developed in recent years against the backdrop of increasing health consciousness, and research is being conducted on various materials used in health foods. There is. Furthermore, these days, people are as conscious about safety as they are about health, and it is preferable to use safe ingredients. desired. For example, wild yam and its extracts are used as ingredients for health foods, and have been widely studied for their functionality, such as their ability to prevent gray hair (Patent Document 3), and further research into useful functions is desired. .

Japanese Patent Application Publication No. 2010-150160 International Publication No. 2008/123417 Japanese Patent Application Publication No. 2010-195730

"Molecules", MDPI, 2018, 23, 2023, "Effects of Rhizome Extract of Dioscorea batatas and Its Active Compound, Allantoin, on the Regulation of Myoblast Differentiation and Mitochondrial Biogenesis in C2C12 Myotubes"

The present invention was made in view of the above-mentioned background, and aims to provide a composition for strengthening muscles and maintaining and/or improving athletic performance.

While searching for a composition that can strengthen muscles, the present inventors discovered that wild yam has the effect of strengthening muscles, and have completed the present invention. Further, while searching for a composition that maintains and/or improves athletic performance, the present inventors discovered that wild yam has the effect of maintaining and/or improving athletic performance, and thus completed the present invention. Ta.

That is, the present invention is as follows.
[1] A composition for muscle strengthening characterized by containing wild yam.
[2] The composition for muscle strengthening according to [1], wherein the wild yam is a wild yam extract.
[3] The composition according to [1] or [2], which is used to enhance athletic performance.
[4] A composition for maintaining and/or improving athletic performance, characterized by containing wild yam.
[5] The composition for muscle strengthening according to [4], wherein the wild yam is a wild yam extract.

The composition of the present invention has the effect of strengthening muscles. Furthermore, the composition of the present invention has the effect of maintaining and/or improving athletic performance.

FIG. 3 is a diagram showing the measurement results of the number of viable cells in the cell activation activity evaluation of myoblasts in Example 1 and Comparative Example 1. 3 is a diagram showing the measurement results of the mRNA expression level of the PGC-1α gene in Example 1 and Comparative Example 2. FIG. FIG. 7 is a diagram showing the results of a questionnaire for the actual feeling evaluation by oral intake regarding muscle strengthening and maintenance and/or improvement of exercise performance in Example 2 and Comparative Example 3.

[Wild Yam]
The composition of the present invention is characterized by containing wild yam. Wild yam, also called Dioscorea, is a general term for plants of the Dioscoreaceae family, and the wild yam contained in the composition of the present invention is a plant with the scientific name Dioscorea oppositifolia or Dioscorea opposita.

Leaves, stems, flowers, roots, etc. of wild yam can be used, but the parts of wild yam used in the composition of the present invention are roots from the viewpoint of muscle building and maintenance and/or improvement of athletic performance. It is preferable that In addition, when using wild yam roots, leaves, stems, and flower parts may be included together with the roots.

As the wild yam contained in the composition of the present invention, a harvested wild yam may be used as it is, or a processed wild yam may be used. When using processed Walid yam, for example, pulverized products such as powder and granules, squeezed products, and extracts can be used. The juice or extract may be in liquid or slurry form, but it is preferable to use dry powder. Among these, pulverized products and extracts are preferred, and extracts are particularly preferred, from the viewpoint of muscle-strengthening action and maintenance and/or improvement of exercise performance. Note that in the present invention, the term "extract" is a concept that includes a dry powder of an extract (a product obtained by drying and powdering an extract). The processed wild yam product may be one produced by a method commonly known by those skilled in the art, or one that is available on the market.

Examples of the wild yam extract contained in the composition of the present invention include extracts, diluted or concentrated solutions thereof, and dry powders thereof. Examples of the solvent used for extraction include water; lower alcohols such as methanol, ethanol, isopropanol, and butanol; lower esters such as ethyl acetate and methyl acetate; acetone; and a mixed solvent of these and water. Among these, water, ethanol, or hydrous ethanol is preferable from the viewpoint of muscle strengthening effect and exercise performance improving effect, and hydrous ethanol is particularly preferable. In the case of aqueous ethanol, it preferably contains less than 85% by volume of ethanol, more preferably 10 to 80% by volume, and even more preferably 30 to 75% by volume. And/or from the viewpoint of improving effects, those containing 70% by volume are particularly preferred. Further, the obtained extract may be pulverized by spray drying, freeze drying, etc., if necessary, and excipients may be added during pulverization.

The extraction method used to obtain the wild yam extract is not particularly limited, and it can be extracted by commonly used methods (for example, immersion extraction, reflux extraction, supercritical fluid extraction, etc.). In addition, the extraction temperature when obtaining the wild yam extract can be arbitrarily set between room temperature and the boiling point of the solvent. For example, extraction is performed at a temperature between room temperature and the boiling point of the extraction solvent with shaking, without shaking, or under reflux. be able to. When the extraction temperature is around the boiling point, reflux may be performed as necessary.

The amount of wild yam to be blended in the composition of the present invention may be suitably contained within the range where the effect is achieved. For example, the composition of the present invention may contain 0.1 to 100% by mass, preferably 0.75 to 95% by mass, and preferably 1.5 to 80% by mass, in terms of dry mass. More preferably, it is particularly preferably contained in an amount of 3 to 60% by mass from the viewpoint of muscle strengthening effect and maintaining and/or improving exercise performance.

There is no particular limit to the intake amount of wild yam in the present invention, but in order to enjoy its effects more effectively, it is preferable that the intake amount of wild yam is 10 mg or more per day for adults, and 50 mg or more per day. It is more preferable to take in an amount of 100 mg or more, and even more preferably to take in an amount of 100 mg or more.

[Composition for muscle strengthening]
The composition of the present invention has an excellent myoblast activation effect by containing wild yam. Activating myoblasts promotes the proliferation of myoblasts, helping to increase muscle strength, and can help recover muscle strength that has been lost due to injury or illness, maintaining muscle mass. By increasing it, you can strengthen your muscles. The composition of the present invention exhibits an excellent muscle strengthening effect by containing wild yam. In addition, the composition of the present invention can maintain the amount of exercise by increasing muscle mass, increasing muscle strength, and recovering, and has the effect of maintaining and/or improving exercise performance. , has the effect of maintaining and/or improving athletic performance and increasing (improving) physical strength.

[Composition for maintaining and/or improving athletic performance]
In the present invention, maintaining and/or improving athletic performance means maintaining or improving the ability exhibited during exercise, and more specifically, it refers to maintaining and/or improving the ability exhibited during exercise. means to maintain or improve one's ability to achieve results. The composition of the present invention has an excellent effect of promoting PGC-1α gene expression by containing wild yam. By promoting gene expression of PGC-1α, the number of mitochondria in brown fat cells is increased, and exercise performance can be maintained or improved by promoting energy metabolism. The composition of the present invention maintains and/or improves excellent athletic performance by containing wild yam.

The composition of the present invention can be used as an oral composition for muscle strengthening, and such an oral composition contains wild yam and can be distinguished from other products in that it strengthens muscles. For example, the main body, packaging, instruction manual, or advertising material (advertisement media) of the product according to the present invention may include information such as muscle strengthening, promotion of muscle synthesis, inhibition of muscle breakdown, or Suppressing, maintaining, and increasing muscle mass (muscle weight, muscle cross-sectional area, muscle density), suppressing, maintaining, and improving muscle quality, suppressing, maintaining, and increasing muscular strength (power, endurance), and decreasing athletic ability. Suppress/maintain/improve, suppress/maintain/improve decline in metabolism (basal metabolism, resting and exercise metabolism), suppress/maintain/increase loss of lean body mass, prevent/improve muscle fatigue, improve metabolism through muscle strengthening , locomotive syndrome preventive/improving effects, and sarcopenia preventive/improving effects are included within the scope of the present invention. The oral composition for muscle strengthening of the present invention may be one in which wild yam is indicated as an active ingredient, but is not limited to one in which wild yam is indicated as an active ingredient on the product packaging or the like. For example, the active ingredient may not be specified. Moreover, even if it is a general food product, it is included in the scope of the present invention that is manufactured and sold with indication of its use. For example, the scope of the present invention also includes foods that are sold with personal impressions of those who have consumed them that mention muscle improvement on their homepages. In addition, with regard to foods with functional claims that include wild yam as a functional ingredient, based on papers that show muscle building, etc. as scientific basis for their functionality, and that have the function of building muscles as a reported claim, the Generally speaking, this notification indication refers to muscle strengthening and is therefore included in the scope of the present invention.

Specifically, the muscle-building composition of the present invention includes pharmaceuticals (including quasi-drugs) and so-called health foods. ``Suppress the breakdown of metabolism'', ``Increase muscle strength'', ``Suppress decline in walking ability, maintain, improve and improve'', ``Improve metabolism by strengthening muscles'', ``Suppress metabolic decline'', ``Prevent muscle fatigue''.・Recovery", "Suppression and maintenance of loss of balance ability", "Shape up", "Macho", "Slim macho", "Beautiful body", "Bedridden prevention", "Bedridden prevention", "Fall prevention", "Muscle Examples include "Improve metabolism by strengthening" and "Maintain muscle mass and strength." The subjects who take the oral composition of the present invention are not particularly limited as long as they need to strengthen their muscles, but include people who want to get in shape, athletes, and elderly people with weak legs. Preferred examples can be given.

The composition of the present invention can be used as an oral composition for maintaining and/or improving athletic performance, and such oral composition contains wild yam, and is a product that maintains or improves athletic performance. There is no particular restriction as long as it can be distinguished from other products, and for example, the main body, packaging, instruction manual, or promotional material (advertisement media) of the product according to the present invention may include information on maintaining athletic performance. The scope of the present invention includes products that are labeled as having the functions of improving exercise performance, improving endurance during exercise, and promoting energy metabolism. The composition for maintaining and/or improving athletic performance of the present invention may be one that displays wild yam as an active ingredient, but is limited to those that display wild yam as an active ingredient on the product packaging, etc. do not have. For example, the active ingredient may not be specified. Moreover, even if it is a general food product, it is included in the scope of the present invention that is manufactured and sold with indication of its use. For example, the scope of the present invention also includes foods that are sold with personal impressions of those who have consumed them, including testimonials that refer to the maintenance or improvement of athletic performance on their homepages. In addition, based on scientific evidence of functionality based on papers showing maintenance and improvement of athletic performance, we have submitted claims for functionally labeled foods that contain wild yam as a functional ingredient and that they maintain and/or improve athletic performance. Foods with functional claims are also included in the scope of the present invention, since the reported claims essentially mean maintenance and/or improvement of athletic performance.

Specifically, the composition for maintaining and/or improving athletic performance of the present invention includes pharmaceuticals (including quasi-drugs) and so-called health foods.・Improve", "Maintain/improve a high physical level", "Improve athletic ability", "Improve endurance", "Increase endurance", etc. can be exemplified. The subjects who take the oral composition of the present invention are not particularly limited as long as they need to maintain and/or improve their athletic performance, but include people who aim to get in shape, athletes, and people with weak legs and hips. Preferred examples include the elderly and the like.

The composition of the present invention can be used, for example, for pharmaceuticals (including quasi-drugs), functional foods for which efficacy claims have been approved by designated organizations, such as foods with functional claims, foods for specified health uses, and foods with nutritional function claims. It can be used as a so-called health food.

The composition of the present invention may be in the form of a capsule, soft capsule, tablet, powder, granule, liquid, granule, rod, plate, block, solid, round, paste, cream, or caplet. Examples include shape, gel shape, chewable tablet shape, and stick shape. It may be in the form of ice cream, jelly, cookies, cake, chocolate, plastic bottle drinks, etc. Among these, capsule, soft capsule, tablet, powder, granule, round, and chewable tablet forms are preferred, and capsule, soft capsule, tablet, powder, and granule forms are particularly preferred.

The composition of the present invention can be produced by a known method by adding other ingredients other than wild yam, if necessary. Other ingredients other than wild yam include water-soluble vitamins (vitamin B1, vitamin B2, vitamin B3, vitamin B5, vitamin B6, vitamin B12, vitamin B13, vitamin B15, vitamin B17, biotin, folic acid, vitamin C, vitamin P ), vitamins such as oil-soluble vitamins (vitamin A, vitamin D, vitamin E, vitamin K); minerals such as calcium, magnesium, phosphorus, iron; flavanoids or flavonoids such as hesperidin and quercetin; proteins such as collagen; Examples include peptides; amino acids; animal fats and oils; vegetable fats and oils; ground products or extracts of animals and plants; excipients, lubricants, and fluidizing agents.

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited thereto.

[Test 1: Myoblast activation test]
Example 1 Roots of wild yam (Dioscorea oppositifolia) were extracted with a 70% ethanol aqueous solution, the resulting extract was dried, and then crushed to obtain a hydrous ethanol extract (white powder) of wild yam roots 10 μg/ mL
Comparative Example 1 Water-containing ethanol extract of roots of Dioscorea esculenta (light brown powder) 10 μg/mL

(1) Mouse skeletal muscle-derived myoblasts (C2C12, RIKEN) were grown at 37°C in a 5% _CO2 incubator using a ^75cm2 flask containing DMEM medium containing 10% fetal bovine serum (FBS). , cultured.
(2) Cultured cells were suspended and collected by trypsin treatment, seeded in each well of a collagen-coated 96-well plate at a cell density of 8.0 x 10 ³ cells/well, and then incubated at 37°C and 5% CO ^2. Preculture was carried out for 24 hours in an incubator.
(3) After removing the medium from each well, wash each well twice with 200 μL/well of DMEM, add DMEM medium (differentiation induction medium) containing 2% horse serum (HS), and store at 37°C with 5% CO ² The cells were cultured in an incubator for 6 days to induce differentiation into myotubes.
(4) The medium was removed, and 100 μL/well of a differentiation induction medium containing the test substance prepared to a predetermined concentration was added, and cultured at 37° C. in a 5% CO ² incubator for 24 hours. The total concentration of the test substance in the medium was 10 μg/mL.
(5) The medium was removed, washed twice with 200 μL/well of PBS, and 150 μL/well of Cell Counting Kit-8 (manufactured by Dojindo Chemical Co., Ltd.) diluted 30 times in volume with serum-free DMEM was added.
(6) After standing in a 5% CO ² incubator at 37° C. to allow appropriate color development, the absorbance of each well at 450 nm was measured. Based on the obtained data, the ratio of the number of viable cells to the control (% of control) was calculated based on the following formula, and the myoblast activation activity was evaluated.
% of control= (Data sample - Data blank) / (Data control - Data blank) × 100
Data sample: Absorbance of Example 1 and Comparative Example 1
Data control: absorbance of control
Data blank: blank when there are no cells

FIG. 1 shows a summary of the calculation results of the ratio of viable cell numbers in Example 1 and Comparative Example 1, with the control as 100%.

As shown in FIG. 1, Example 1 containing wild yam extract had significantly higher myoblast activation activity than Comparative Example 1. Therefore, the oral composition containing wild yam according to the present invention is useful in muscle building.

[Test 2: PGC-1α gene expression test]
Example 1 Roots of wild yam (Dioscorea oppositifolia) were extracted with a 70% ethanol aqueous solution, the resulting extract was dried, and then crushed to obtain a hydrous ethanol extract (white powder) of wild yam roots 10 μg/ mL
Comparative Example 2 Pulverized roots of Dioscorea batatas (brown powder) 10 μg/mL

(1) Mouse skeletal muscle-derived myoblasts (C2C12, RIKEN) were grown at 37°C in a 5% _CO2 incubator using a ^75cm2 flask containing DMEM medium containing 10% fetal bovine serum (FBS). , cultured.
(2) Cultured cells were suspended and collected by trypsin treatment, seeded in each well of a collagen-coated 24-well plate at a cell density of 5.0×10 ⁴ cells/well, and then incubated at 37°C and 5% CO ^2. Preculture was carried out for 24 hours in an incubator.
(3) After removing the medium from each well, wash each well twice with DMEM, add DMEM medium (differentiation induction medium) containing 2% horse serum (HS), and place in a 37°C, 5% CO ² incubator. The cells were cultured for 6 days to induce differentiation into myotubes.
(4) The medium was removed, and 500 μL/well of a differentiation-inducing medium containing the test substance prepared to a predetermined concentration was added, followed by culturing in a 5% CO ² incubator at 37° C. for 24 hours. The total concentration of the test substance in the medium was 10 μg/mL.
(5) Remove the medium, wash twice with PBS, collect RNA using RNeasy Mini Kit (manufactured by QIAGEN), and collect RNA using ReverTra Ace (registered trademark) qPCR RT Master Mix with gDNA Remover (manufactured by Toyobo). cDNA was synthesized.
(6) Quantitative real-time PCR was performed using QuantiNova SYBR Green PCR Master Mix (manufactured by QIAGEN) using the obtained cDNA as a template and PGC-1α primers (manufactured by QIAGEN) to measure the amount of PGC-1α gene expression. . As an endogenous control, the expression level of the GAPDH gene was measured using a GAPDH primer (manufactured by QIAGEN), and a relative value was calculated with the gene expression level of the control as 1.

FIG. 2 shows a summary of the results of the gene expression levels of Example 1 and Comparative Example 2, with control as 1.

As shown in FIG. 2, in Example 1 containing wild yam extract, the expression level of PGC-1α gene was significantly higher than in Comparative Example 2. Therefore, the oral composition containing wild yam according to the present invention is useful in maintaining and/or improving athletic performance.

[Test 3: Feeling evaluation by oral intake]
The purpose of this study was to evaluate the effects of oral intake of wild yam on muscle building and maintenance and/or improvement of athletic performance using the method described below. A placebo-controlled cross-over comparative study was conducted.

(1) Test food The roots of wild yam (Dioscorea oppositifolia) were extracted with a 70% ethanol aqueous solution, the resulting extract was dried, and then crushed. Capsules of test food A (Example 2) were produced by encapsulating the test food in invisible capsules. Test Food B (Comparative Example 3) was made into capsules using white capsules that were not visible inside, similar to the capsules used for Test Food A, so that they could not be distinguished from the capsules of Examples in terms of appearance. was manufactured.
Test food A (Example 2) Wild yam root hydrous ethanol extract (powder) 300 mg/1 capsule Test food B (Comparative example 3) Wild yam root hydrous ethanol extract (powder) 0 mg/1 capsule

(2) Test method Three healthy adult males were asked to ingest two capsules of either test food A or B with dinner for three days in each observation period, before ingesting the test food and after ingesting the test food for three days. Subjects were asked to evaluate whether they felt a decrease in muscle strength using the following questionnaire and evaluation criteria. There was a 2-day washout period between each observation period.

Contents of the questionnaire (evaluation items) Muscle strength has decreased or become weak.

Questionnaire evaluation criteria: Not feeling it: 1 point Feeling it mildly (feeling it slightly): 2 points Feeling it moderately: 3 points Feeling it severely (feeling it strongly): 4 points Feeling it extremely severely (I can't help but feel it): 5 point

The total score obtained was calculated, and the relative value of the total score after 3 days of intake (after intake/before intake) was calculated, taking the total score before intake as 1. In other words, the smaller the value, the less likely you are to feel a decrease in muscle strength after 3 days of ingesting the test food compared to before ingesting the test food. means high. The results obtained are shown in FIG.

As shown in FIG. 3, the composition containing wild yam extract according to Example 2 of the present invention had a lower score in the questionnaire regarding muscle strength reduction than Comparative Example 3 which did not contain wild yam, i.e. , I rarely felt that my muscle strength was decreasing or becoming weak. Muscles can be strengthened by maintaining or increasing muscle mass by increasing and recovering muscle strength. Furthermore, athletic performance can be maintained and/or improved by increasing muscle strength, recovery, and increasing muscle mass based on these. Therefore, the oral composition containing wild yam according to the present invention is useful in muscle building and maintaining and/or improving athletic performance.

Examples of various embodiments of the present invention are listed below. However, the technical scope of the present invention is not limited to these.

[Prescription examples 1 to 3] (capsules)
As shown in Table 1, wild yam extract obtained by extracting the root of wild yam (Dioscorea oppositifolia) with aqueous ethanol was mixed and then filled into a gelatin-containing film to produce capsules (contents 200 mg per capsule, film 80mg). When the obtained capsules were ingested, they were excellent in muscle strengthening effects and in maintaining and/or improving athletic performance.

[Formulation examples 4 to 6] (Soft capsules)
As shown in Table 2, the contents of soft capsules were prepared by mixing wild yam extract obtained by extracting the roots of wild yam (Dioscorea oppositifolia) with aqueous ethanol and other raw materials (300 mg per capsule). Subsequently, the contents of the soft capsules were encapsulated in a gelatin capsule film (150 mg per capsule) according to a conventional method to produce soft capsules. When the obtained soft capsules were ingested, they were excellent in muscle strengthening effects and in maintaining and/or improving exercise performance.

[Prescription examples 7-9] (tablets)
As shown in Table 3, a wild yam extract obtained by extracting the roots of wild yam (Dioscorea oppositifolia) with aqueous ethanol was mixed with other raw materials and then molded using a tableting machine to produce tablets (1 250mg per grain). When the resulting tablets were ingested, they were excellent in muscle strengthening effects and in maintaining and/or improving exercise performance.

[Production Examples 10 to 12] (Powdered beverage)
As shown in Table 4, a powder (for beverages) was prepared by mixing wild yam extract obtained by extracting the roots of wild yam (Dioscorea oppositifolia) with aqueous ethanol and other raw materials. When 3 g of the obtained powder (for drinks) was mixed with 100 mL of water and ingested, it was found to be excellent in muscle strengthening effects and in maintaining and/or improving exercise performance.

[Production Examples 13 to 15] (granules)
As shown in Table 5, wild yam extract obtained by extracting the roots of wild yam (Dioscorea oppositifolia) with aqueous ethanol was mixed with other raw materials, and then put into a fluidized bed granulator and mixed for several minutes with air flow. , 300 mL of water was sprayed onto this for 1 minute to perform granulation. The obtained granules were screened through a 30 mesh sieve to produce granules. When the obtained granules were ingested, they were excellent in muscle strengthening effects and in maintaining and/or improving exercise performance.

[Production Examples 16 to 18] (Beverage)
As shown in Table 6, a beverage was prepared by mixing a water-containing ethanol extract of the root of wild yam (Dioscorea oppositifolia) (wild yam extract) and other raw materials, and the beverage was filled into a 500 mL container. When the resulting beverage was ingested, it was found to be excellent in muscle strengthening effects and in maintaining and/or improving exercise performance.

The oral composition of the present invention can be used as a food that has a muscle-strengthening effect, and therefore has high industrial utility. Furthermore, the oral composition of the present invention can be used as a food that maintains and/or improves athletic performance, and therefore has high industrial utility.

Claims (2)

A composition for strengthening muscles, characterized by containing wild yam. A composition for maintaining and/or improving athletic performance, characterized by containing wild yam.