A Study of Knowledge and Use High School Athletes and ...€¦ · The Kuder-Richardson internal consistency coefficient was .69. The survey was administered to 509 students from six

International Journal of Sport Nutrition, 1995, 5, 232-245 O 1995 Human Kinetics Publishers, Inc.

High School Athletes and Nutritional Supplements: A Study of Knowledge and Use

Susan j. Massad, Nathan W. Shier, David M . Koceja, and Nancy T. Ellis

Factors influencing nutritional supplement use by high school students were assessed. Comparisons were made between various groups of sports participants and non-sports participants. The Nutritional Supplement Use and Knowledge Scale was administered to 509 students. Mean supplement use score was 10.87 (SEM = 0.50, range 0-57). Mean knowledge score was 13.56 (SEM = 0.16, range 1-21). Significant relationships (p < .01) were obtained for supplement knowledge with use, and supplement use with gender. ANOVA found significant differences between supplement use by gender (p < .01), supplement use by sports category (p < .05), and knowledge scores by sports category (p < .01). Discriminant function analysis indicated knowledge, supplement use, and subscores for protein, vitamins/minerals, and carbohydrates were best discriminators of sport group membership. Greater knowledge about supplements was associated with less use; hence, education about supplements can be a deterrent to use. This study may help coaches, athletic trainers, athletic directors, teachers, physicians, and parents identify nutritional misconceptions held by adolescents.

Key Words: steroid alternatives, vitamins, sports drinks, protein

Athletes have supplemented their diets for ergogenic purposes since ancient times. Athletic performance is mostly attributed to genetic endowment and training state, yet the emphasis placed on winning has led many to seek nutritional products purported to enhance performance. Widespread use among athletes of various nutritional products such as vitamins, minerals, sports drinks, and protein powders has been documented (7, 8, 10). High school and college athletes, especially, are trying to achieve results attributed to anabolic steroids by using supplements known as "steroid alternatives" (5, 6, 8). The majority of such products have not been tested on humans and certainly not in the doses recommended by advertisements in bodybuilding and weight lifting magazines. Reports

S.J. Massad is with the Department of Health Studies, Springfield College, 263 Alden St., Springfield, MA 01109. N.W. Shier and N.T. Ellis are with the Department of Applied Health Science, and D.M. Koceja is with the Department of Kinesiology, Indiana University, Bloomington, IN 47405.

High School Athletes / 233

of nausea, vomiting, dizziness, and heart palpitations associated with steroid alternative use have been received by the Food and Drug Administration (6).

Few scientific studies have been conducted on high school athletes' use of nutritional supplements. Research on nutrition in adolescent athletes indicates that (a) use of vitamin and mineral supplements is prevalent among high school and college athletes (1, 7, 8), (b) high school and college athletes are trying to achieve perceived benefits of anabolic steroids by using steroid alternatives (5, 6, 8), and (c) many high school athletes use protein supplements in an attempt to improve performance (8, 9).

Bazarre et al. (1) examined vitamintmineral supplement use and nutritional status of 90 collegiate athletes. Supplements were used by 46 (51%) of subjects (100% of the females and 51% of the males). None of the control group of 15 subjects reported supplement use. Dietary intake, measured with 7-day records, demonstrated that intakes of most nutrients from food alone was greater for the supplement users than for the nonusers, indicating that supplement users may exhibit additional healthy lifestyle habits.

Singh et al. (12) examined dietary intakes and biochemical profiles of a group of ultramarathoners, ages 27 to 51 years (M = 40), who participated in a 100-mile cross-country endurance run. Mean daily intakes of selected vitamins and minerals from food alone during the practice and prerace (4 consecutive days prior to event) periods, for men and women combined, met or exceeded the Recommended Dietary Allowances (RDA) for all nutrients except zinc (mean intake 65% of RDA). Twelve of the 17 subjects (70.60%) reported taking vitamin/ mineral supplements. Biochemical indices of vitamin and mineral status were normal.

Review of these studies indicates that use of vitamin and mineral supplements is common for certain groups of athletes. This study was conducted to determine factors that influence the use of nutritional supplements by high school athletes who participated in various sports.

Methodology

The Nutritional Supplement Use and Knowledge Scale was developed for this study by Massad and Shier in 1993 (1 1). This scale, in survey format, consists of demographic data, a list of 23 nutritional supplements with indication of frequency of use, a 21-item quiz testing knowledge about supplements, and a section indicating sports participation and reasons for using or not using supplements.

Content validity of the survey was determined by a jury of 13 experts. The survey was pilot tested on a high school physical education class (n = 32). The Spearman-Brown split-half reliability coefficient was .78. The Kuder-Richardson internal consistency coefficient was .69.

The survey was administered to 509 students from six Indiana high schools. For sports participants, selection was based upon their participation in at least one sports team sponsored by their school. The non-sports participants were selected in a nonrandom fashion, by teachers from study halls and physical education classes. The sports classification defined by the Committee on Sports Medicine, American Academy of Pediatrics (4), was used. The classification encompasses (a) contact/collision sports: boxing, field hockey, football, ice

234 / Massad, Shier, Koceja, and Ellis

hockey, lacrosse, martial arts, soccer, and wrestling; (b) limited contact sports: baseball, basketball, bicycling, diving, field (high jump and vault), gymnastics, horseback riding, skating, skiing, softball, squash, and volleyball; (c) strenuous sports: aerobic dancing, crew, field (discus, javelin, and shot put), running, swimming, tennis, track, and weight lifting; (d) moderately strenuous sports: badminton, curling, and table tennis; and (e) nonstrenuous sports: archery, golf, and riflery. Since there were no teams that fit into Category (d), this category was dropped. An additional category, defined as non-sports participation, was added and included students who did not participate in any organized sports teams.

Supplement use scores were computed by designating a Liken-type point value, ranging from 0 to 4, for frequency of reported use. A score of 0 was designated for never use this, while a score of 4 was designated for use more than once a day. Supplement use subscores were also computed and included separate scores for (a) protein and amino acid supplements added together, (b) vitamins and minerals, (c) steroid replacers, (d) weight gain formulas and formulas designed to bum fat, and (e) carbohydrate loading and fluid replacement drinks.

Statistical analysis on the findings consisted of correlation coefficients to determine relationships between (a) supplement use and supplement knowledge, (b) use of supplements used for building muscle and burning fat (referred to as "anabolic scores7') and supplement knowledge, (c) supplement use and gender, and (d) supplement use and year in high school.

Univariate analyses of variance (ANOVA) for unequal sample sizes were computed to determine differences between (a) supplement use scores by year in high school, gender, and sports category (independent variables); (b) anabolic scores and the same independent variables; and (c) supplement knowledge scores and the same independent variables.

Discriminant function analysis determined (a) if supplement use scores (0-96) could discriminate between sports category; (b) if supplement use "subscores," computed for protein supplements, steroid alternatives, vitamins and minerals, and carbohydrate supplements, could discriminate between sports category; and (c) if knowledge scores could discriminate between sports category. All statistics were computed using the Statistical Package for the Social Sciences (SPSSx) (13).

Findings

Demographic data indicated the following distributions: 159 freshmen, 164 sopho- mores, 94 juniors, and 90 seniors; 205 females and 302 males. The subjects were 14 to 18 years old with a mean (M) age of 16.70 + 1.45. The number of subjects in each sports category was 136 contact, 92 limited contact, 137 strenuous, 18 nonstrenuous, and 1 18 non-sports participants (8 missing responses).

Reported Frequency of Supplement Use

Data regarding frequency of nutritional supplement use are summarized in Table 1. Supplement use scores ranged from 0 to 57 (M = 10.87, SEM = 0.50), indicating a wide range of use. The total possible points for supplement use was 96 (24 supplements x 4 points for use of a supplement more than once a day = 96).


The means and standard errors of the means of supplement use scores by year in high school, gender, and sports category are summarized in Table 2.

For the knowledge section of the survey, the Kuder-Richardson internal consistency reliability coefficient was .68. The Spearman-Brown split-half reliability coefficient was .76. Distribution of responses for each knowledge item is provided in Table 3.

Knowledge scores ranged from 1 to 21 (M = 13.56, SEM = 0.17). The mean score for females was 14.20 (SEM = 0.16) and for males 13.13 (SEM = 0.17).

Significant Pearson product moment correlation coefficients were found for supplement knowledge scores with supplement use scores (r = -.14, p < .01); supplement knowledge scores with scores computed for supplements used primarily to build muscle mass and bum fat-protein drinks, amino acids, steroid replacers, weight gain formulas-and for formulas designed to bum fat (r = -.16, p < .01); and for supplement use scores and gender (r = .17, p < .01). However, the variance (3) for all three correlations indicated that only a small percentage

Table 1 Frequency of Nutritional Supplement Use Among 509 High School Students

Type of supplement Subjects reporting

weekly to daily use Percentagea

Fluid replacement drinks Multivitamins or multiminerals Vitamin C Protein drinks Carbohydrate loading drinks Calicum Iron B-complex Vitamin A Vitamin E Weight loss formulas Amino acids Weight gain formulas Zinc Steroid alternatives Supplements derived from fat, such

as medium chain triglycerides Formulas designed to bum fat Selenium Bee pollen Ginseng Royal jelly Pangamic acid

"ange of respondents = 505-508.


Table 2 Means and SEM of Supplement Use Scores by Year in High School, Gender, and Sports Category

Mean SEM

Year in high school Freshman Sophomore Junior Senior

Gender Male Female

Sports category Contact Limited contact Strenuous Nonstrenuous Non-sports participation

of the variance of scores on the dependent variables could be accounted for by the independent variables. The correlation coefficient obtained for supplement use scores and year in high school was not significant.

Differences between supplement use scores by year in high school, gender, and sports category, determined by ANOVA, indicated no significant difference for supplement use by year in high school. A significant difference was found between supplement use by gender, with males scoring higher than females (F = 16.52, p < .01). For males, M = 12.40 and SEM = .73, while for females, M = 8.43 and SEM = .57.

A significant difference was found between supplement use by sports category (F = 2.48, p < .05). Mean scores and SEM for participants in each category are summarized in Table 2. A Tukey's post hoc test indicated significant differences O, < .05) between scores for contact and nonstrenuous, contact and limited contact, contact and strenuous, and nonparticipation and nonstrenuous. There were no significant interactions.

ANOVA was used to determine differences between anabolic scores by year in high school, gender, and sports category. No significant difference was found between anabolic scores by year in high school, but a significant difference was found between anabolic scores by gender, with males scoring higher than females (F = 40.02, p < .01). The total number of points possible for anabolic scores was 20. For males M = 2.33 and SEM = 0.19. For females, M = 0.79 and SEM = 0.10. A significant difference was also found between anabolic scores by sports category (F = 7.25, p < .01). Mean scores and SEM for participants in each category were (a) contact sports, M = 3.12, SEM = 0.33; (b) limited contact, M = 0.75, SEM = 0.16; (c) strenuous, M = 1.26, SEM = 0.17; (d) nonstrenuous, M = 1.00, SEM = 0.45; and (e) nonparticipation, M = 1.50, SEM =


Table 3 Distribution of Responses for 509 High School Students Concerning Knowledge of Nutritional Supplements

Item

% Subject responses by option (* indicates right answer)

True False

1. Powdered or liquid protein drinks offer nutritional advantages over protein found in natural foods.

2. The best way to develop bigger muscles is to exercise.

3. Consumption of specific amino acid mixtures may lead to nutritional imbalance, as an overload of one amino acid may inhibit ab- sorption of other amino acids.

4. The amino acid arginine, when taken as a supplement, greatly in- creases the production of human growth hormone.

5. Most of the extra protein eaten (i.e., beyond daily needs) will be stored as fat.

6. B-vitamins give athletes an extra boost of energy.

7. Taking high doses of vitamins A, D, and K can be harmful.

8. An athlete cannot possibly get all of hisher calcium needs through dietary sources, so supplements are necessary.

9. An athlete cannot possibly get all of hisfher iron needs through dietary sources, so supplements are necessary.

10. Taking high doses of zinc and selenium can be harmful.

11. Formulas containing medium chain triglycerides, such as "MCT Fuel," help the body effi- ciently bum fat.

12. Steroid replacers, such as "Hot Stuff," contain safe ingredients to help reduce fat while building muscle tissue.

(continued)


Table 3 (continued)

Item

13. Some steroid replacer supplements cause stomach pain, nausea, and dizziness.

14. Dietary supplements containing animal glandular material such as "bull testicles" provide a significant amount of the male hormone testosterone.

15. The ingredient "yohimbe bark" (an ingredient in some steroid replacers) is a natural source of methyltestosterone, an illegal anabolic steroid. Since yohimbe bark is a natural ingredient, it is safe.

16. Use of weight loss formulas seldom results in long-term weight loss.

17. Formulas designed to bum fat also stimulate muscle growth.

18. "Glucose polymer solutions," also known as "carbohydrate loading drinks" (such as "Exceed Hi Carbohydrate Source," "Ga- torlode," "Ultrafuel," or "Car- bofuel"), are designed for use before, during, and after exercise of long duration.

19. The only way to adequately re- place the sodium and potassium lost from sweat during exercise is to drink a sports beverage designed for rehydration.

20. The supplements "Vitamin B- 15" (also known as "pangamic acid"), "ginseng," "bee pollen," and "royal jelly" all improve endurance.

21. Nutritional supplements sold at health food stores have all been scientifically tested and are safe.

% Subject responses by option (* indicates right answer)

True False r

*79.42 17.32 0.45


0.22. Tukey's post hoc test indicated significant differences (p < .05) between scores for contact and limited contact, contact and nonstrenuous, contact and strenuous, and contact and nonparticipation. There were no significant interactions.

Differences between knowledge scores by year in high school, gender, and sports category, determined by ANOVA, indicated a significant interaction for the independent variables, year in high school and gender (F = 3.14, p < .05). Analysis of simple main effects indicated that sophomore females scored significantly higher than the other groups (F = 7.72, p < .01). A significant difference was found between knowledge scores by sports category (p < .01). Mean scores and SEM for participants in each category were (a) contact, M = 12.75, SEM = 0.30; (b) limited contact, M = 14.17, SEM = 0.35; (c) strenuous, M = 14.57, SEM = 0.30; (d) nonstrenuous, M = 15.11, SEM = 0.71; and (e) nonparticipation, M = 12.71, SEM = 0.39. Tukey's post hoc test indicated significant differences (p < .05) between scores for strenuous and nonparticipation, strenuous and contact, nonstrenuous and contact, and nonstrenuous and nonparticipation.

When a discriminant function analysis of each variable was conducted separately (i.e., supplement use scores, supplement use subscores, and knowledge scores), no significant discriminant functions were extracted. Discriminant function analysis of all variables combined indicated that five variables were the best discriminators of sport group membership. In order of significance, these variables included knowledge scores, supplement use scores, and the subscores for protein, vitamin and minerals, and carbohydrates.

Discriminating variables correctly classified 35.6% of the students into the five sports categories. They were best able to correctly classify participants in nonstrenuous sports (58.08%) and were least able to correctly classify participants in limited contact sports (14.60%). Classification results are summarized in Table 4.

The structure matrix (pooled within-groups correlations between discriminating variables and the derived functions) is summarized in Table 5. Examination of the matrix indicates that discriminant function was dominated by knowledge scores, with a structure coefficient of .58. Total supplement scores and protein scores also had strong structure coefficients, which were -.51 and -.56, respec- tively.

The three most common reasons given for using the eight most often used supplements are summarized in Table 6. Each supplement is listed as well as the number of subjects who gave each response. The five most reported reasons for not using supplements are summarized in Table 7.

Discussion

In this sample, the reported frequency of use of certain supplements was similar to that in other studies. For example, 41.70% of subjects in this study reported weekly to daily use of vitaminlmineral supplements, and 21.70% reported weekly to daily use of protein supplements. Krowchuk et al. (8) found a 33.00% use rate of vitaminlmineral supplements and a 35.00% use rate of protein supplements in a sample of high school athletes. Bazarre et al. (1) found that 51.00% of college athletes in their study sample used vitamin/mineral supplements.


Table 4 Classification Results of Discriminant Function Analysis

Predicted group membership Group No. of cases 1 2 3 4 5

1. Contact 128 49 38.3%

2. Limited contact 82 6 7.3%

3. Strenuous 120 15 12.5%

4. Nonstrenuous 17 3 17.6%

5. Nonparticipation 114 14 12.3%

Note. Discriminant function analysis was conducted to determine if supplement use scores, knowledge scores, and supplement use subscores could discriminate between sports category. Percentage of "grouped" cases correctly classified: 35.36%.

Table 5 Structure Matrix: Pooled Within-Groups Correlations Between Discriminating Variables and Canonical Discriminating Functions

Variable Function

1 2 3 4

Knowledge score .58061 .40213 -.48155 .6036 Total supplement score -.5 1392 .lo528 .45314 -.04470 Carbohydrate score -.3 1096 .67595 .50046 -.40205 Vitamin & mineral score -.22 160 -.I5868 .609 12 .00649 Protein score -.56653 ,36375 .31695 .57661

Overall, reported use of nutritional supplements was not especially high in this sample. Supplement use scores were significantly higher for males than for females. A possible explanation could be that advertisements for protein powders and steroid alternatives usually appear in bodybuilding magazines that are more popular with male athletes. Participants in contact sports such as football, boxing, and wrestling scored significantly higher than other groups for overall supplement use, as well as for use of supplements designed for anabolic purposes. This finding could be attributed to the emphasis placed on increasing muscle mass to compete in these particular sports. This warrants attention, since high doses of supplements purported to increase muscle mass (protein powders, amino acids, and steroid alternatives) have harmful side effects, such as nausea, dizzi-


Table 6 Reasons Given by High School Students for Using Nutritional Supplements

Supplement Reason for use Number

responding

Fluid replacement drinks 1. Like the tasteltastes better than water. 2. Quench thirst. 3. Coachlteam supplies itlit's available

at practice Multivitamin/minerals 1. To make sure I get what I need to

stay healthy 2. I don't usually eat properly/parent(s)

told me to 3. For energy

Vitamin C 1. To get more energy when I work out 2. To boost my immune systembad

coldlwanted to avoid cold 3. To stay healthy

Protein drinks 1. To show and build musclelget stronger

2. To gain weight 3. To get biggerlbuild up body weight

Carbohydrate loading drinks 1. To load up on carbohydrates & get more energy

2. Like the taste 3. To keep healthy & stay in shape

Calcium 1. For my healthlto become stronger 2. To keep healthy & stay in shape 3. For calcium deficiency in bones

Iron 1. Iron deficiency anemia 2. For energy 3. For my health/to exercise/get strong

B-complex 1. For energy 2. For my health 3. My mom told me it would prevent

acne

ness, stomach pain, and dehydration (5). The types of supplements typically used by tennis players, swimmers, runners, and golfers (sports drinks) have few, if any, harmful side effects. If this study were to be replicated, a use of different sports classification may be warranted, since there was a wide variety of sports in the American Academy of Pediatrics (4) classification.

It is interesting to look at the most commonly stated reasons for use of supplements for which the greatest frequency of use was reported. For example, many students reported using vitamins and mineral supplements "for energyw-an


Table 7 Reasons Given by 509 High School Students for Not Using Supplements

Reason Number

responding

1. Do not believe in them/feel there is no need 2. Don't know much about themfwhere to get them 3. They seem unhealthy/unnatural/have side effects 4. Not enough moneyltoo expensive 5. Do not want to

incorrect assumption, since vitamins and minerals are nonenergy nutrients and cannot be used by the body as an energy source. Certain vitamins and minerals are involved in energy metabolism, and iron is involved in hemoglobin synthesis. These are perhaps the reasons they are believed to provide energy.

Regarding vitamin C , many reported using it to stay healthy, boost the immune system, or prevent and treat colds. Although vitamin C is involved in immune function, evidence that it prevents or alleviates colds remains unsubstan- tiated.

Six subjects reported using iron to treat iron-deficiency anemia, while 6 reported using calcium for general health, bone health, or strength. Iron and calcium deficiencies are not uncommon in individuals who restrict calories (16). Both of these nutrients have crucial roles in athletic performance. Calcium deficiency leads to decreased bone density, making stress fractures more likely. Iron deficiency leads to decreased hemoglobin synthesis, resulting in lower oxygen- carrying capacity of red blood cells and shortness of breath. However, athletes, like all other groups, can obtain adequate amounts of both of these nutrients from a balanced diet (16).

A number of misconceptions surfaced from responses regarding protein drinks; the most popular reasons given for their use were to build muscle, to gain weight, and to gain energy. While protein is involved in muscle tissue synthesis, its importance in the diet is often overrated by athletes. Muscle tissue synthesis is largely a function of weight resistance training with proper energy intake, not extra dietiuy protein consumption.

Several subjects reported using vitamins A or E for the health of their skin. The protective lining of the skin serves as a barrier to infection from bacteria. If vitamin A is deficient, the cells secrete keratin, causing them to dry and harden. If the cells die, they become hosts to bacterial infection. However, scientific research does not support taking vitamin A supplements to improve the health or appearance of the skin (2).

Many unfounded claims have been made about vitamin E, and in the 1960s and 1970s, it was said to improve athletic endurance, increase sexual potency, and delay wrinkling of the skin (2). More recent studies have indicated that adults who took vitamin E supplements for more than 2 years had a reduced risk of coronary heart disease compared to those who did not take supplements (14).


In this sample, 6.69% of the subjects reported using the supplements designated as steroid alternatives. This figure is consistent with research studies that analyzed use of anabolic steroids. Buckley et al. in 1988 (3) reported a 6.64% use rate of anabolic steroids by male high school seniors. A more recent study indicated that 6.30% of Indiana high school football players from all grade levels were current or former users of anabolic steroids (15). The most frequent reasons reported for using nutritional products designed as steroid alternatives were to build muscles and increase body mass.

The mean knowledge score of 13.56 correct responses out of 21 questions (64.57%) was relatively low. There are at least three possible explanations. First, it is possible that the questions were too difficult. Sport nutrition is seldom covered in standard high school health curricula. If nutrition is a content area, it may be included in a home economics or general health course, and rarely does it include units on nutrition in relation to athletics or sports supplements. Second, lower scores may reflect the many misconceptions and myths that prevail in regard to ergogenic properties of nutritional supplements. Third, perhaps adver- tising claims have been successful in boosting expectations of certain supplements.

The mean knowledge score for females was greater than that for males. This difference may be attributed to females' greater overall interest in nutrition. Advertisements for particular nutritional products, such as weight loss formulas, vitamins, iron, and calcium, typically target females. Most women's magazines, including those aimed at younger women, are replete with articles on the subject of dieting.

Fewer than 75% of the subjects were able to correctly answer 18 out of 21 (85.71%) of the knowledge questions. For questions regarding protein, approximately one-third of the subjects believed that protein drinks offered nutritional advantages over protein found in foods and did not know that extra protein consumed would be stored as fat if energy intake exceeded need. The protein found in supplements is actually derived from natural foods, and excess of either will increase fat storage (16). Yet, 88.98% correctly answered the item stating that the best way to develop bigger muscles was to exercise.

Regarding amino acids, close to one-half of the subjects believed that arginine greatly increased human growth hormone production and did not know that consuming specific amino acids could lead to nutritional imbalance. To determine the effect that amino acids have on serum growth hormone concentra- tion, Lambert et al. in 1993 (9) examined the effects of oral amino acid supplements on male bodybuilders who were given the amino acids arginine, lysine, and omithine or a placebo. Serum growth hormone concentrations were not altered consistently following ingestion of the amino acid supplements recommended by the manufacturers.

For questions regarding vitamins, approximately one-third of the subjects did not know that high doses of vitamins A and D could be harmful, and close to one-half believed that B vitamins were a source of energy. Vitamins A and D are likely to be toxic if taken in large enough quantities. If a diet is deficient in B vitamins, supplements may improve performance but are not likely to be effective if dietary intake is adequate (7).

Regarding minerals, one-third of the subjects believed that athletes could not get adequate iron and calcium from diet alone. Careful selection of foods will provide both minerals, eliminating the need for supplements (7, 16).


Close to one-half of the subjects believed that formulas containing medium chain triglycerides could help the body bum fat, and over one-half believed that formulas designed to bum fat could stimulate muscle growth. Approximately one-third of the subjects believed that steroid replacers contained safe ingredients to help reduce fat while building muscle tissue. Close to one-half of the subjects believed that animal glandular material (e.g., "bull testicles") provided significant amounts of testosterone. The amount of testosterone retained in the testes is only slightly higher than one would obtain from eating any other part of the animal. Eating animal testes will at best have a placebo effect, and at worst may cause indigestion and be a waste of money (6). It is also interesting to note that 79.42% knew that steroid replacer supplements caused stomach pain, nausea, and dizziness.

Perhaps the last question, regarding testing and safety, reflects the greatest reason for the many misconceptions that emerged. Close to one-half of the subjects (47.83%) believed that nutritional supplements sold at health food stores had all been scientifically tested and were safe to use. Actually, the Food and Drug Administration has not approved the safety of many products sold in health food stores and has not substantiated the claims made on them (5).

For the specific sample surveyed, the following inferences are warranted. (a) The relationship between knowledge about nutritional supplements and use of supplements is small but statistically significant. Greater knowledge is associated with less use; hence, more education about supplements, particularly regarding those that pose health threats, may discourage use. (b) Males report greater use of all supplements than females, (c) males report greater use of supplements designed for anabolic use than females, and (d) supplement use varies by sports category.

These findings help to identify certain educational needs of high school athletes. First, the popular belief that all supplements available at health food stores have been scientifically tested and are safe needs to be addressed, since many have been shown to have harmful effects (5, 6). When health food stores began to open in the 1960s and 1970s, their primary purpose was to make natural foods available. Since that time, however, the evolution of supplements has given rise to a much more profitable health food business. Many of these stores are franchise and are most often located in shopping malls that are frequented by teenagers.

Conclusions

The variables tested in this study could be used to enable coaches, physical education teachers, athletic trainers, athletic directors, health educators, and parents to identify common misconceptions held by adolescent athletes and nonath- letes regarding nutrient needs and nutritional supplements. Professionals may then target particular categories of athletes for educational programs aimed at optimal nutrition for athletic performance. Sports physicians can use this informa- tion when obtaining a medical history from adolescent patients. For instance, they may want to include questions regarding nutritional practices, particularly if there are complaints of nausea, vomiting, or dizziness.


References

1. Bazarre, T.L., A. Scarpino, R. Sigmon, L.F. Marquart, S.M. Wu, and M. Izurieta. Vitamin-mineral supplement use and nutritional status of athletes. J. Am. Coll. Nutr. 12(2): 162-169, 1993.

2. Boyle, M.A., and E.N. Whitney. Personal Nutrition. St. Paul, MN: West Publish- ing, 1989.

3. Buckley, W.E., C.E. Yesalis, K.E. Friedl, W.A. Anderson, A.L. Streit, and J.E. Wright. Estimated prevalence of anabolic steroid use among male high school seniors. JAMA 260(23):3441-3445, 1988.

4. Committee on Sports Medicine, American Academy of Pediatrics. Recommendations for participation in competitive sports. Pediatrics 81(5):737-739, 1988.

5. Cowart, V. Dietary supplements: Alternatives to anabolic steroids? Physician Sportsmed. 20(3): 189-198, 1992.

6. Friedl, K.E., R.J. Moore, and L.J. Marchitelli. Steroid replacers: Let the athlete beware. NSCA J . 14(1):14-19, 1992.

7. Haymes, E.M. Vitamin and mineral supplementation to athletes. Int. J. Sport Nutr. 1:146-169, 1991.

8. Krowchuk, D.P., T.M. Agnlin, D.B. Goodfellow, T. Stancin, P. Williams, and G.D. Zimet. High school athletes and the use of ergogenic aids. Am. J. Dis. Child. 143(4):486-489, 1989.

9. Lambert, M., J.A. Hefer, R.P. Millar, and P.W. McFarlane. Failure of commercial amino acid supplements to increase serum growth hormone concentrations in male body builders. Int. J. Sport Nutr. 3:298-305, 1993.

10. Lemon, P. Protein and amino acid needs of the strength athlete. Int. J. Sport Nutr. 1:127-145, 1991.

11. Massad, S.J., and N.W. Shier. Nutritional Supplement Use and Knowledge Scale. Unpublished manuscript, Indiana University, Bloomington, Indiana, 1993.

12. Singh, A., P. Evans, K.L. Gallagher, and P.A. Deuster. Dietary intakes and biochemical profiles of nutritional status of ultramarathoners. Med. Sci. Sports Exerc. 25(3):328- 334, 1993.

13. SPSS Inc. SPSS" User's Guide. Chicago, 1992. 14. Stampfer, M.J., C.H. Hennekens, J.E. Manson, G.A. Colditz, B. Rosner, and W.C.

Willet. Vitamin E consumption and the risk of coronary heart disease on women. N. Engl. J. Med. 328(20):1444-1449, 1993.

15. Stilger, V.G. Indiana High School Football Players' Attitude, Knowledge, and Use of Anabolic-Androgenic Steroids. Unpublished doctoral dissertation, Indiana University, Bloomington, Indiana, 1993.

16. Williams, M.H. (1992). Nutrition for Fitness and Sport (3rd ed.). Dubuque, IA: Brown.

Documents

A Study of Knowledge and Use High School Athletes and ...€¦ · The Kuder-Richardson internal consistency coefficient was .69. The survey was administered to 509 students from six