Original

Research

Communications-survey

Dietary patterns, gastrointestinal complaints, knowledge of recreational triathletes14 Jeanne Frank

D Worme, M Moses,

Thomas J Doubt, Anita and Patricia A Deuster

ABSTRACT

Dietary

trointestinal

habits,

complaints

were

nutrition

Singh,

knowledge,

evaluated

hemoccult bleeding.

1 1 h/wk swimming,

weekly distances biking, and running,

of 5.3, 1 16.5, respectively.

averaged

1 1 59 1 U for women

ergy intake

9058

respectively;

53.8%

Mean

ofvitamins

intakes

ommended

Dietary

of

and

the

energy

and most

Allowances

and

50

slides to determine Triathbetes trained

was

and 40.9 km for Mean daily en-

from

minerals

(RDAs),

and gas-

in 2 1 female

male triathletes; 30 completed the frequency of gastrointestinal with

Christopher

and men,

carbohydrates.

exceeded

but

many

the Rechad

intakes

below RDAs for some nutrients; > 60% had low zinc and copper intakes. Because 39% took a daily multivitamin-mineral supplement, some had intakes 200-600% above the RDA. Although there were notable misconceptions about nutrition, nutrition knowledge was high. Upper-gastrointestinal complaints, reported by 50%, included bloating and abdominal gas; the incidence of positive hemoccult slides was 27%. The relation edge,

among and

performance, gastrointestinal

dietary patterns, nutrition function remains to

AmfClinNutr

lished.

KEY

WORDS

minerals,

be

knowlestab-

J Ryan,

ested ful

to other

vided, intakes,

Carbohydrates,

energy,

fluids,

hemoccult,

information

(2, 3), interfere with

gastrointestinal

Participation

has risen 690

or consecutive

additional

sharply

with

athletes.

on the

such

For

such

nutrition

because

optimization

guidelines

may

dur-

also

recommendations

be use-

to be

pro-

knowledge

their

choice

ofthese

ofspecific

athletes foods

would

may

be dic-

tated by misconceptions or inadequate information. To date few formal studies have evaluated the nutrient intakes of triathletes in training, and there is minimal information on their flutrition knowledge (I, 4). This study was undertaken to determine 1) total energy intake and the relative contributions of protein, CHO, and fat to total energy; 2) training schedules and an estimate of overall energy balance; 3) intake ofvitamins and minerals and the frequency

of supplement

use;

4)

methods

of fluid

replacement

during training; 5) source and accuracy ofnutrition knowledge; and 6) incidence of digestive symptoms and presence of Gb bleeding in a group ofrecreational triathletes. Methods The study

It is generally assumed that the dietary requirements of athbetes are comparable with those ofnonathletes. That is, the diet must provide sufficient energy from protein, carbohydrate (CHO), and fat and appropriate quantities of vitamins, minerals, and fluids. However, energy expenditure by an athlete may be two-to-five-times greater than that of a nonathbete depending on the type of sport and intensity of training (1). Present dogma states that the increase in energy expenditure must be balanced by a concomitant increase in energy intake coupled with adequate supplies of vitamins and minerals. One particubar group of athletes that adds a new dimension to the issue of energy expenditure is triathletes. Triathletes train for multievent competitions and often undergo multiple training sosmay impose

for performance

competition;

information on the current dietary patterns, nutrient and GI function of each athlete is useful. Moreover,

be important

vitamins

Introduction

day

guidelines

and

l990;51:690-7.

supplementation,

on one

in dietary

ing training

sity

sions

and nutrition

days.

Such

a training

schedule

demands on the body’s available stores usual meal schedules(4), and be associated (GI)

disturbances

in triathbons

in the past

for

(5, 6). competition

few years,

and

and tnathletes

recreation

are inter-

Am J C/in Nutr

of the

by the Uniformed

Sciences

(USUHS)

Services

Human

Use

UniverResearch

Committee and conducted in conjunction with an amateur triathbon (1.5 km swim, 40 km bike, and 10 km run) held in September 1987. Letters were sent to all 450 registered entrants explaining the project and inviting them to participate. Thirtyfour percent (n = 1 52) of the race entrants expressed interest on registration day and a general overview of the project was From

the Department

of Military

Medicine,

Uniformed

Services

University of the Health Sciences; the Diving Medicine Department, Naval Medical Research Institute, Bethesda, MD; and the Gastroenterology Service, Walter Reed Army Medical Center, Washington, DC. 2

The opinions

or assertions

contained

herein are the private

ones of

the authors and are not to be construed as official or reflecting the views of the Department of Defense, the Uniformed Services University of the Health Sciences, the Naval Medical Research Institute, or the

Walter

Reed Army Medical

3

Supported

4

Address

by NMRDC

reprint

requests

Center. N0002487WR

Printed

13039.

to PA Deuster,

Medicine, USUHS. 4301 Jones 4799. Received March 2, 1989. Accepted for publication June

1990:5 1:690-7.

Downloaded from https://academic.oup.com/ajcn/article-abstract/51/4/690/4695205 by Washington University School of Medicine Library user on 19 May 2018

was approved Health

Bridge

Road,

Department Bethesda,

of Military MD

20814-

7, 1989.

in USA. © 1990 American

Society for Clinical

Nutrition

NUTRITION provided. form.

Triathletes Each

a stamped research

voluntarily

subject

was

envelope team, an

signed

given

for returning explanation

cards, an activity questionnaire, disease questionnaire, and were weighed on a portable percent

body

technique

Height

was

provided

consent

that items dietary

on site by using technique

and

to the record

the bioelectrical

by each

do

691

TRIATHLETES None none

The

of the

had

20 questions

nutrition

(Gen),

erals

(V&M),

quiz,

their

were

and

ofthe

on the theory

dividing

the number

fat and to the

ber of questions). lated

athlete.

and

“I

don’t

entire

in nutrition

quiz

ofcorrect

for each the

questions

from

be obtained was

the in the

from

the by

total

of the categories

num-

was calcu-

of correct,

were

mm-

determined

by 20 (the

number

responses

general and

are shown

score

responses

In addition, know”

can

topics:

vitamins

answers

an overall

A score

similarly.

Selected

the correct

subject

four

(H&D),

(Ath).

and

each

a degree

into

disease

athletics

A copy

had

categorized

and

categories,

appendix.

subjects in a triathbon.

health

For

bone body.

control

participated

authors.

is based

lower resistance than current is introduced

OF ences.

included

a nutrition quiz, a digestivestool-hemoccult cards. Subjects scale (to the nearest 0.5 kg), and

(7). This

that bean tissues offer when a small electrical

informed

packet

the completed the study,

of

fat was estimated

impedance

an

a research

PATTERNS

incorrect,

tabulated

for

the

two

groups. Dietary

intake

and

energy

balance

Detailed written instructions record were provided. Dietary etary-record weekend asked

on how intakes

cards for 3 consecutive within 6 wk after the

day

to record

period

Lastly,

their

as defined

dietary

by the

The

dietary the Q

records

derived

from

CHO,

tively

the

a usual and

training

not

to overlap

to food and beverages, were to be recorded.

Kensington,

MD),

food descriptors, Handbook 8 (8).

by multiplying

during subject

and 1 were

were evaluated by a registered Intake Nutritional Analysis

computerized Corporation,

sists of > 6000 revised USDA

dietary on di-

days: 2 weekdays triathbon. Subjects

intakes

individual

any competitive event. In addition vitamin and mineral supplements using (Med

to keep a 3-d were recorded

fat, gram

4210

The

protein,

values

by

are

con-

from

for energy

alcohol

17, 38,

dietitian System

database

of which

and

weight

whose

all

(in kJ)

were

17, and

the

obtained 30,

An activity

questionnaire

on current

history,

sources

gested

during

distances swimming,

was administered

training of

programs,

nutrition

training

information,

sessions,

and

types

The

information

energy

cited

constants

were

cost of each

by Katch

used

to calculate

running min

energy expenditure based on a 4.96 mm/km

diture

was

estimated

crawl stroke was estimated

at

speed mated

km/h. energy

of25.8 from

metabolic equations

and

as 0.67

McArdle

or research uals had

was derived The

from

following

for each

kJ.kg.min

activity:

based

on

A gross daily energy expenditure expended during these activities

rate. from

‘.

a fast

was estiand basal

rate was calculated with Id . kg ‘ . h ‘ for women and weights obtained on the day for all computations with the stable was

during the that subjects

was

estimated

by

were quiz

2 1 men

asked with

of

who

institute also took college or advanced

20 questions. worked the quiz. degrees

in either

without

recording reported

a medical

In brief, the

the

to obtain

to the

proce-

discrimination

percent

index

of subjects

in the

0.30

is considered

satisfactory.

The

difficulty

index

was

± 0.23,

respectively,

indicating

that

there

were

no serious

prob-

lems with the test. information

The digestive-disease questionnaire was administered to asofGI complaints and/or digestive symptoms during training or competition. Subjects were instructed to answer with never, seldom, frequently, or disabling to the series of questions. Never and seldom were considered negative responses whereas frequently and disabling were considered positive. Hemoccult in accordance

group

of

school

Thirty ofthe 38 individin the biomedical sci-

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slides were with written

prepared at home by the triathletes instructions; subjects mailed the

slides back to the without rehydration

laboratory for analysis. Slides were developed to avoid an unacceptable number of false-

positive

Standard

results. were

St atistical

graded

as positive

procedures

were

followed

and

the

or negative.

analysis

Data were analyzed by the Statistical Analysis System (SAS) computer package ( 1 3). Means and standard errors (SEM) were used as descriptive statistics for the total population and for subpopulations. Mean differences between subgroups were tested by analysis of variance (ANOVA) and Duncan mean separation procedures. Results

consulting

A control

subtracting

on the quiz

according

derived by dividing the number ofcorrect responses by the total number ofsubjects; the higher the number, the lower the level ofdifficulty. The mean discrimination and difficulty indices averaged across all questions were 0.41 ± 0.16 (1± SD) and 0.53

General

to complete,

(12).

performed

indices

lower 27% ofthe total population who answered a given question correctly from the upper 27% ofthe total population. The range ofpossible discrimination indices is - 1 .0 to 1.0; an index

characteristics

Seventy-one

a nutrition and

by Sax

slides

quiz

All triathletes 17 women

for energy

18.6 min/km; and cycling energy expenditure as 0.7 1 kJ . kg’ . min based on an average

assumption that weight remained periods. The basis ofthis assumption stable weights for the past year.

sources,

in-

training

questionnaire to calculate (10).

expenditure

fluid

The

was estimated as 0.92 Id . kg pace; swimming energy expen-

Basal metabolic Linder (1 1); 3.76 4. 18 Id . kg ‘ . h ‘ for men. Body preceding the triathlon were used

Nutrition

activity

described

was

difficulty

sess the frequency

training

of

dure

Gastrointestinal

infor-

and

education.

and times reported in the activity biking, and running were used

expended.

to gather

competition

analysis

and

respec-

(9).

mation

an item

discrimination

(47%)

ofthe

1 52 persons

who

picked

up packets

at the race registration completed and returned all questionnaires and the dietary record (2 1 women and 50 men). Their general characteristics are presented in Table I; all 7 1 completed the triathlon. For all those who finished the competition (n = 322), average finish times were 180.5 ± 2.9 mm (n = 73) for women and 172. 1 ± 1 .5 mm (n = 249) for men. Overall

WORME

692 TABLE

1

General

characteristics

of recreational

intakes

Women

32±2

Men Height (cm) Women

39±

(17-48)

1

(22-68)

166±1 178±1

Men Weight (kg) Women

(160-178) (152-196)

60.2±

Men

1.2(48-67) ± 1.1 (61-89)

74.7

Body fat (%)

Women Men BMI (kg/m2)t

24.2 ± 0.7 (16-30) 1 5.2

±

0.6(9-34)

Women

21.9

±

0.4(18-25)

Men

23.7±0.4(20-35)

SEM.

±

4 .

=

Range

given

in

parentheses.

n

Women,

2 1;

=

men,

SO.

t Body

mass index.

finish

times

study, times

respectively, were were comparable

for

the

women

and

men

who

I 79.0 ± 4.7 and with the finish

participated

169.4 times

in this

± 3.3 mm; these for all triathbon

participants. Forty-five percent of the women and 6 1% of the men in the study placed in the top halfofrace finishers. The activity questionnaires indicated that 80% had competed in prior 10-km road races and 42% had completed at least one marathon race. Other athctic competitions included cycling

(33%)

peted

swimming

(women

distances ±

and

in 8 ± 1 previous

training 0.3,

for 1 16.5

12.4

(27%)

races.

The

triathbons

and

spent

± 1 .0 and

men

10.9

subjects

had

± 0.5

h/wk).

±

in

Weekly

biking, and running averaged 5.3 7.3, 40.9 ± 2.3 km, respectively, for women and No significant difference was noted between

intakes

Mean

intakes

significant

ofselccted

differences

nutrients

between

are shown

in Table

women and men for body weight.

were

of

2. No found

folic

acid

(folacin)

± 1.1%,

30.0

± 0.8%,

15.1

± 0.3%,

and

3.4

± 0.6%

of the

total energy intake. Daily energy expenditures (basal metabolic rate plus expenditure for swimming, biking, and running) were estimated to be9359 ± 343 and 12 034 ± 272 kJ/d forthewomen and men, respectively. ± 1 34 kJ/d

Energy 405

Energy

intake

expended

during

for the women and 4460 minus energy expenditure

± 6 14 kJ/d

for the women

and

exercise averaged ± 105 kJ/d for the

was estimated

4 18 ± 548

3900

men. to be

kJ/d

for the men. effect of food or

These values do not account for the thermic energy expended for other daily activities. Mean intakes of all vitamins studied, except vitamin E for men. were above the Recommended Dietary Allowance (RDA) (9) when food alone was considered (Table 3). However, some individuals consumed less than the RDA as shown in Figure 1 Although 39% of the population (12 women and .

Downloaded from https://academic.oup.com/ajcn/article-abstract/51/4/690/4695205 by Washington University School of Medicine Library user on 19 May 2018

vitamin

E were

below

the

quiz

The control population was similar in men 35 ± 2 y), weight (women 56.9 ± ± 1.8 kg), and height (women 167 ± 1 cm) to triathlete subjects. Education was breakdown ofeducation for the triathletes

TABLE 2 Intakes ofenergy, energy-providing and men triathletes4

when intakes were normalized Overall, the subjects consumed 10 835 ± 447 kJ/d, or 155.9 ± 5.4 U . kg. d . Protein intake averaged 1.4 ± 0.4 g/kg. The energy derived from CHO, fat, protein, and alcohol, respectively, averaged 53.8

and

supplement on a daily several days per week,

RDA for > 50% ofthe men and women. Supplementation increased mean intakes of vitamins A, E, C, thiamin, and riboflavin by women to > 600% of the RDA and intakes by men up to 300% ofthe RDA (Table 3). Mean intakes ofselected minerals from food and mean total intakes (food plus supplements) are presented in Table 4. Although mean total intakes of calcium, magnesium, zinc, and iron were above the RDA, > 40% ofthe population consumed less than the RDA for magnesium and zinc from food alone (Fig 2). Copper intake in reference to the Food and Nutrition Board’s Estimated Safe and Adequate Intake range (ESAI) (9) followed a similar trend. The patterns ofintake by women and men were similar except for iron: 8 1% ofthe women and 4% of the men were below the RDA when intake from food alone was considered. When iron from supplements was included, 43% of the womea and 2% of the men had iron intakes below the RDA. Sodium intakes were significantly lower for women than for men (p < 0.05), and > 67% ofthe men consumed > 3300 mg/d, the upper limit ofthe ESAI (9); only 33% ofthc women consumed more than this amount. Mean potassium intakes were within the ESAI range. Water was the beverage most frequently consumed during training by women and men. Glucose-polymer drinks were used in addition to or as a substitute for water by 29% of the women while biking and 19% while running and by > 50% of the men while biking and running. Nutrition

com-

1 1 ± 0.5 h/wk

swimming,

men combined. sexes. Dietary

AL

1 5 men) took a multivitamin-mineral basis and another 6% took a supplement

triathletes4

Age(y)

n

ET

nutrients,

age (women 1.3 kg and

3 1 ± 1 y, men

77.8

cm and men 179 ± 1 also comparable. The and control subjects,

and alcohol

by women

Intake normalized for body weight

Intake

1kg Energy

(U)

Women Men Carbohydrate Women Men Protein

152.6 ± 9.2

155.9±6.7

(g) 290± 372±15

17

(174-455)

4.9

(153-711)

5.1±0.2

±0.3

84±7 102±4

(55-151)

1.4±0.3

(38-172)

1.4 ±0.2

73±5 92±5

(42-135) (36-171)

1.2 ±0.2 1.2 ±0.3

9± 4 15±3

(0-5

0.2

(g)

Women Men Fat (g) Women Men Alcohol(g) Women Men 4

9 058 ± 477(5 421-14 785) 11591±410(11310-18860)

1)

(0-85)

1± SEM. Range given in parentheses.

±

0.1

0.2 ±0.1

NUTRITION TABLE

PATTERNS

3

OF

TRIATHLETES

was found

Daily intakes supplements

ofselected

vitamins

from

food alone

and food plus

Food

intake4

Total

in a surprisingly

women and hematemesis

intake4t

rim was

RDA

A (mg

used

Women Men

3 157 ± 393 2303±198

8 157 ± 2044 4215±447

800 1000

ofthe tion

regularly who

laboratory

REj)

barge percent

of subjects

(39%

of

18% of men) although clinical bleeding, as either or blood in stools, was infrequent (< 10%). Aspi-

30 persons Vitamin

693

by 45%

returned

after

the triathlon,

hemoccult-positive regularly;

of the

was taking

population.

hemoccult

8 (27%)

subjects

none

total

completed

Of the

slides

had positive

used

aspirin

supplemental

to the

slides.

or arthritic vitamin

Half

medica-

C.

C (mg)

Vitamin

Women Men

171 ±209 200±173

Vitamin

E (mg

60 60

8.0 9.2

±

27.7

1.4

74.9

±

± 0.9

34.9

± 7.8

1.7±0.1 2.1±0.1

8 10

7.9±3.7 3.7±0.7

1.0 1.4

(mg)

2.2 2.6

(mg

± 0.2

8.3

± 3.7

1.2

± 0. 1

4.3

± 0.7

1.6

± 1.5

13

II)

NE

Women Men

21.9 30. 1

±

1.4

30.8

±

1.5

40.9 ± 3. 1

18

B-6 (mg)

Vitamin

Women Men Fobacin

2.0 2.6

± 0.2

8.6 ± 3.6

2

± 0.2

4. 1 ± 0.6

2

(mg)

patterns

and

The

302±245 386±22 B-12

512±58 504±33

400 400

Women Men

4.9 ± 1 .0 S. 1 ± 0.3

1

4.4

± 4. 1

9.8

±

athletes

(1

for

3

3

41±SEM.

records intake

but

that

athletes

a bow-CHO gen

and

study

are of increasing

inter-

the athlete.

indicated that the tnathletes than reported in other studies the

by

diet

relative

some

energy

there

diminished

had a of tri-

contributions

1 5).

Studies

from

successive

decrease

The

produce

strenuous

daily

glyco-

in the

energy gradual

(2),

that when

in muscle

triathletes

of their

may

by Costill

(3, 16, 17) showed

during

-‘55%

value

3,

is a progressive endurance.

only low

(2,

and others

is consumed

periods, derived

somewhat

t Food

, 4)

to nutrition and

and Miller(15),

exercise

2.2

relating

researcher

CHO, fat, and protein were comparable and followed the US Dietary Goals (14). Although the Dietary Goals encourage a diet wherein 58% of the energy is derived from CHO, a diet with 65-70% of the energy coming from CHO has been advoCostill

(mg)

issues the

3-d dietary mean energy

lower

cated

Women Men Vitamin

The triathletes surveyed in this study devoted 10-12 h/wk to training, often with several workouts per day, reflecting a serious commitment to the sport. Because dietary intakes have been shown to affect performance and general health, dietary est to both

Women Men Niacin

Discussion

TE)

Women Men Thiamin (mg) Women Men Riboflavin

998±493 357±78

from declines

CHO.

present This

in perfor-

and supplements.

:j: Retinol

equivalents.

§ a-Tocopherol II Niacin

equivalents.

100

equivalents. 80 a

respectively, degree, and high

was

There on ±

were

the 2.0%

no

there

scored

was

± 5.6%,

V&M

category 3.2%

53.5%

in

of

categories.

scores

on

gender

overall

than

with

Women

as compared the V&M

college

and

C

the two

the

men

highest

scored

73.8

with 55.2 ± 3.4% category compared

40

E

groups

0

20

54.2 were

0

subcategories.

difference:

the

60 0

10.5%;

correct answers (triathletes 56.5 ± 2.3%). Similarly, there

0.01),




10% ofthese

for the symptoms.

A history

C

completed

20

in Figure

3.

vomiting, whereas

0

the

individuals by 50% subjects

of

rou-

of anemia

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B12

FIG I . The percent of women (upper panel) and men (lower panel) who consumed vitamins in amounts below the RDA from food alone (hatched bars) and from food plus supplements (open bars). B1 , thiamm;

B2, riboflavin;

folacin,

folic

acid.

WORME

694 TABLE

4

Daily intakes supplements

ofselected

minerals

alone

food

intake4

Food

Calcium (mg) Women Men Magnesium (mg) Women

from

Total

1259± 105 1250±77

and from

plus

food

intake4

RDA

1433± 125 1320±81

800 800

362 ± 32

300 350

Men Women Men Copper (mg)t

± 24

402±21

431 ±223

10.6 ± 0.8 13.7±0.8

17.9

2.4

±

I .5 ± 0. 1

2.3

Men

1.8±0.1

2.3±0.2

Iron (mg) Women

14.5±

Men

1.1

21.2±2.5

Sodium (mg)t Women Men Potassium (mg)t Women Men

4.i±SEM. t For copper.

0.3

±

iron

15 2-3

2-3

Range ofintakes over a period intake relative

ance athlete may 19). In the present

1875-5625 1875-5625

and potassium.

estimated

safe and adequate

still

of sustained to activity

training. level may

protein

between

requirements 1 .2 and

ofthc

1.8 g. kg

.d

(18,

less

than

the

RDA,

depending

on

sidered,

excessive

a small

percent

amounts, the mean was skewed above uals consumed large amounts ofother ularly

vitamins

C and

consumed

the RDA. vitamins

Some individas well, partic-

A.

Intakes ofcabcium from food alone were above the RDA for almost all subjects, a finding consistent with other studies on triathletes (1, 4). Of interest was the finding that calcium intakes by triathletes were much higher than values in the Nationwide Food Consumption Survey (20, 2 1). In contrast to calcium,

below

mean

the

RDA

intakes

ofzinc

and

ESAI.

minerals, sodium and either met or exceeded

potassium the ESAI

and potassium were reported by when intakes were expressed rela-

and

and may

minerals

serve

In the

are

general

population

important

essential

women

cofactors

roles

and

in energy

in performance

me-

(23, 24,

and

copper

respectively,

from

food

alone

were

for the women

and

Downloaded from https://academic.oup.com/ajcn/article-abstract/51/4/690/4695205 by Washington University School of Medicine Library user on 19 May 2018

100

a 4

80

60

.

men and was con-

because

intake.

tabolism

0

endur-

the vitamin in question. For vitamin E 64% of the women had intakes below the RDA when food alone but

to energy

vitamins

In addition, a low also tend to dimin-

>

consumed

men

and potassium.

66% consumed > 1.2 g/kg and only 9% of the population had intakes below the RDA. Our mean intake of 1.4 g/kg is somewhat lower than the 1.65 and 2.0 g/kg reported by others (1 , 4) for triathletes. It remains an arguable question as to what protein intake optimizes triathbon performance. Mean intakes of most vitamins were above the RDA when food alone was considered and markedly higher among triathletes taking vitamin supplements, a finding consistent with other reports on triathletes ( I , 4). Nonetheless, portions of the populations

supplements.

men were reported to consume less sodium (women 2500 mg/ d and men 3400 mg/d) and potassium (women 2200 mg/d and men 3600 mg/d)(20, 21). However, ifmean intakes of sodium and potassium by the triathlete were adjusted for energy, intakes were similar to literature values. To date, there are no specific RDAs and no known minimum daily requirements for athletes in training. Thus, the RDAs remain the recommendation ofchoicc. Because several

1585-6853 1626-7456

range study,

it is likely

tive

3656±276 4196± 191

that

12 mo,

10 1100-3300 1100-3300

suggests

previous

18

Mean protein intake by the triathlctes was in excess of the RDA (9), but the RDA assumes light-to-moderate activity. research

in the

27.8±3.1

ish performance.

New

cycles

28.5±2.9 l830-4138j 1340-7995

for sodium

menstrual

(9). Similar intakes ofsodium Khoo et al (1) for triathletes

2907± 152 3937±202

sodium.

eight

Unlike the aforementioned intakes ofall women and

is given.

mance energy

men; > 60% ofthe population consumed less than the recommended amount. Similarly, a barge portion (> 40%) of the women and men consumed bess than the RDA for magnesium. Although mineral supplementation lowered these percents, > 25% of both women and men still consumed less than the RDA for some minerals. Consistent with other reports, iron intake was above the RDA only for the 12 women who took supplcments(1, 22). Because 19 ofthe 2 1 women reported haythat the iron requirements ofmost women were not being met. For the men even though iron intake from food alone was above the RDA for all but 2 individuals, 17 men were taking

15

18.9±1.4

Women

t

AL

ing 324

Zinc (mg)

range

ET

C

.

E

40

0

20

0

Ca

4

100

-

80

-

60

-

40

-

20

-

Mg

Zn

Mg

Zn

Cu

F.

a 0

C

0

iIi Ca

1I

FIG 2. The percent ofwomen (upper panel) who consumed calcium, magnesium, zinc, amounts below the RDA from food alone(hatched plus supplements(open bars).

Cu

F.

and men (lower panel) copper, and iron in bars)and from food

NUTRITION

PATTERNS

OF

695

TRIATHLETES

(I)

E

0

0 0

C

E

E

0 #{149}0

>1

U)

.

14

4

C

12

I-

0

E

.;:t

10

C)

,

:

I

6

a

a.

.

-J

4

t

&-

a

.!

E

c

U)

4

15

0

_

.!

E

15

.

0

C)

U)

a

:

,

8

a

0 U

C

4Q.

(I)

. 15

. a.

0

(5

4

0 I-

2

C)

E

z

Digestive

FIG 3. The number responses

25).

(frequent

requirements

gested

that

may

the

be

increased

less than

increased

needs

food intake (24, 25), but as others, do not support consumed

of women

RDA

by an

the present were many

yet they

digestive

activity.

be met

from There

1 8 (hatched

to specific

by

will

data this.

the

out of

or disabling)

were

bars) and men or gastrointestinal

a habit

26).

Again,

that

athletes

that

is prevalent

these

among

individuals

are able

also

to perform

the

over

sug-

to widespread

misinformation

in

information. Information

pertaining

study, as well subjects who and

self-medication despite a lack

with ofevidence

tation

performance

(27)

will

improve

nutrition recommendations The numerous sources nutrition trition.

information

com-

that

their

their

that

range

responses

nutrition

from other

high

in nuquiz

because

sugtheir

our sample of wellsupport personnel. from local newspapers

and sports magazines athletes and health

and the professionals

ceptions of nutrition. advertised over the and is a good source

For example, a common misconception years is that spinach will make you strong ofiron. No doubt this prompted a number

of the

respondents

in spinach. took

the quiz

to choose

In addition,

the

selected

peanut

quiz did indicate may have had

iron

as the

finding butter

that some

predominant

that as being

>

ent study incidence

both the miscon-

nutrient

20%

of those

who

high

in cholesterol

unknown,

but

returned

on dates

reported

a half marathon. se, as seen

Thus,

be associated

with

probability slides

that

may

that

this

was

dominal

gas

aerophagia simply

are

reflect

performance

pect

that

GI

4,

22,

26).

Such

habits

may

be attributed

Downloaded from https://academic.oup.com/ajcn/article-abstract/51/4/690/4695205 by Washington University School of Medicine Library user on 19 May 2018

distur-

with bleeding

the is

the single

tri-

habits

(30).

Some

we cannot

from

than

may

ignore

the

those

per

training,

completed

reported

exercise

intense

Finally,

of these including

strenuous

and

the

hemoccult

who

had

reasons

symptoms

reported

in

previously

reported

in

a comparatively

symptoms

malabsorption. in gastric

because

than

The

race.

to

higher

in-

symptoms, such as heartburn, vomitdiscomfort, and gas. The causes for are uncertain, but bloating and ab-

alterations foods

that

who

nonspecific

and

petition

competitions,

to or lower

and CHO

terns

( 1,

with

the

self-selected

(5), the triathletes

were

noted

and

but consistent cause of the

in other

it is likely

cidence of the upper-GI ing, bloating, abdominal this increased frequency

ing

previously

loss

wk after

subjects

similar

and

supplements

blood

test would be positive. frequency of bower-GI

training

of nutritional

of scientific

subjects since these are (5, 28). Hemoccult mcibasis ofnumerous studthe incidence in the pres-

finding

marathons,

been the

the

study

1

Gb bleeding. the

have

to believe Although

runners

>

in triathbons,

liquids

doses

GI

ofthis

competing

etary

high

to occult

the association

lack been eat-

and

positive

or misinterpretation

was 27%. Our value is higher found in runners (28). The

suggests a prevalence of nutrition misconceptions and/or ofinformation. Other such examples among athletes have reported (4, 26). Widespread use ofunusual foods, atypical patterns.

reported

athbon should be questioned because the athletes continued be active in weeks after the race; several positive specimens

were

for obtaining interested

who

bances were also obtained from the common occurrences among runners dence in the general population on the ies ranges from 2% to 6% (29) whereas

subjects

nutrition

was

scores were comparable with those educated health professionals and Most ofthem derived their information

of intakes,

well-documented

were

to the

knowledge

It appears

nutritional supplethat supplemen-

until

they

(1 , 4, 22,

well.

are provided. cited by the triathletes

indicated

Accordingly,

gested

athletes

a wide

but it is likely that ments will continue

bars)

increase

training

performed

out of 49 (open symptoms.

It was

peting on a high level. Moreover, many were consuming greatly in excess ofthe RDA through vitamin and mineral supplementation,

Symptoms

runners

significance

disturbances

that

motility

tnathletes ingest

would

that

result are

but induce

due

more

and

for dietary

it is reasonable individuals

may to di-

ingest

training

findings

from

they

routinely during

ofthese

is uncertain,

may

Alternatively,

compatto cx-

to

alter

WORME

696 their diets. Dietary modifications before a competition common, and most athletes eat little or nothing for hours before a major competition or training session. altering dietary intake patterns, GI disturbances may utrient absorption and/or increase nutrient losses, blood loss has been implicated as a cause of “sports” (28).

Thus,

nutrition

status

may

be compromised.

are several Besides impair and GI anemia

In the

pres-

ent study, the percent ofsubjects who reported a history of anemia was quite high, and iron intake was below the RDA for most women. However, the individuals with a history of anemia or a low iron intake were not hemoccult positive. Clearly, further work is needed to determine the association between GI complications, dietary patterns, and nutrition status. In summary, the population of triathletes we studied consumed a diet recommended for the average population and comparable with that of other tnathbete populations. The percent of energy derived from CHO was somewhat low relative to reported needs for endurance training. Although 30-50% of the

triathlctes

were

consuming

amounts

below

the

RDA

or

ESAI, others had intakes ofsebected vitamins and minerals that were 200-600% above the RDA. In particular, iron intake by females was low. Vitamin and mineral supplementation was a common practice among athletes, with 39% taking a multivitamin-mineral

edge

supplement

among

ceptions

daily.

the triathbetes

were

present.

The

was high, Finally,

there was a high incidence bloating and abdominal

level

ofnutrition

although

among

of upper-GI gas, and

the

notable triathbetes

complaints, hemoccult

AL

13. SAS Institute

17.

Day for the diet-records

MD: USDA,

Deuster

23.

7. 8.

9.

10. 1 1.

12.

PB, Vigersky

survey

of highly

RA, Singh A, Schoo-

trained

women

runners.

Dietetic Assoc

27.

and mineral mentation.

male triath-

letes. Phys Sportsmed 1987: 1:140-SS. Sullivan SN. The gastrointestinal symptoms of running. N EngI J Med 198 l;304:915. Worobetz U, Gerrard DF. Gastrointestinal symptoms during cxercise in enduro athletes: prevalence and speculations on the etiology. N Z Med J 1985:98:644-6. RJL Systems. Inc. Bioelectricab impedance user’s manual: a review ofbody composition techniques. Detroit: RJL Systems, Inc, 1987. Science and Education Administration, US Department of Agriculture. Composition of foods. Washington, DC: US Government PrintingOffice, 976-1982. [USDA handbook 8 series(1-9).] Committee on Dietary Allowances, Food and Nutrition Board, National Research Council. Recommended dietary allowances. 9th ed. Washington. DC: National Academy Press, 1980. Katch Fl, McArdle WD. Nutrition, weight control and exercise. 3rd ed. Philadelphia: Lea & Febiger, 1988. Linder MC. Energy metabolism. intake, and expenditure. In: Linder MC, ed. Nutritional biochemistry and metabolism with clinical applications. New York: Elsevier Science Publishing Co. Inc. 1988:199-220. Sax G. Principles ofeducational measurement and evaluation. Belmont, CA: Wadsworth Publishing Co. Inc. 1974.

nutrition

Nutrition

Med Sci Sports in health

and

Ex-

and disease.

physical

fitness.

J

76:4373-443.

status of trained Am J Clin Nutr

McMabe

28. per-

Association. 1980;

update.

Clark N, Nelson M, Evans W. Nutrition education for elite female runners. PhysSportsmed 1988; 16:124-35. Weight LM, Noakis TD, Gravesi, Jacobs P. Bernian PA. Vitamins

Med

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CSFII, report 85-3.)

PA, Kyle SB, Moser

American

So.

6.

1986. (NFCS,

Belko AZ. Vitamins and exercise-an crc 1987; 19:5191-6. Shils ME, Young VR, eds. Modern Philadelphia: Lea & Febiger, 1988.

24.

ML, Stevenson RJ. Nutrient inAnn Sports Med 1987; 3:144-

Australian

1988;64:187-93.

EB. Nutritional

Am Diet

Burke LM, Read RSD. Diet patternsofelite

diet on

Nutrition Monitoring Division, US Department of Agriculture. Nationwide Food Consumption Survey: continuing survey of food intakes by individuals: women 19-SO years and their children 1-S years day. Hyattsville, MD: USDA, 1986. (NFCS, CSFII, report 86-1.)

21.

26.

S.

J Appl Physiol

mass.

25.

4.

LF. The effect of a high carbohydrate

Am J Clin Nutr 1987;4S:954-62.

analysis.

2. Costill DL. Energy supply in endurance activities. Int J Sports 1984; S(suppl): 19-21. 3. Sherman WM. Carbohydrate, muscle glycogen, and improved formance. Phys Sportsmed 1987: 1:1S7-64.

NC: SAS Institute

19. Lemon PWR, Yarasheski KE, Dolny DG. The importance of protein for athletes. Sports Med 1984; 1:474-84. 20. Nutrition Monitoring Division, US Department of Agriculture. Nationwide Food Consumption Survey: continuing survey of food intakes by individuals: men 19-SO years, 1 day 1985. Hyattsville,

References 1. Khoo CS, Rawson NE, Robinson take and eating habits oftriathletes.

Cary,

human recovery following prolonged work to exhaustion. Ergonomics 1974; 17:489-97. 18. Tarnopolsky MA, MacDougalliD, Atkinson SA. Influence of protein intake and training status on nitrogen balance and lean body

B Barbara

JD, Green

Brooke

maker

including incidence

basics.

14. Select Committee on Nutrition and Human Needs. US Senate Dietary Goals of the United States. 2nd ed. Washington, DC: Government PrintingOffice, 1977. 15. Costill DL, Miller JM. Nutrition for endurance sport: carbohydrate and fluid balance. Int J Sports Med 1980; 1:2-14. 16. Bergstrom J, Hermansen L, Hartman E, Saltin B. Diet, muscle glycogen and physical performance. Acta Physiol Scand 1967;7l: 140-SO.

22.

studied,

Inc. SAS user’s guide:

Inc, 1982.

knowl-

miscon-

was27%. We acknowledge

ET

athletes

including

effects of supple-

1988:47:186-91.

ME, Peura DA, Kadakia

SC, Bozek Z, Johnson

LF. Gas-

trointestinal blood loss associated with running a marathon. Dig Dis Sci 1986:31:1229-32. 29. Simon JB. Occult blood screening for colorectal carcinoma: a critical review. Gastroenterology l985;88:820-36. 30. Owen MD, Kregel KC, Wall PT, Gisolfi CV. Effects of ingesting carbohydrate beverages during exercise in the heat. Med Sci Sports

Exerc 1986; 18:568-75.

APPENDIX Selected

questions

1. Carbohydrates

replacement derives

from are

the

particularly the

lowest

drates? Ath a. 1 small plain b. 2 brownies c.

5-oz

d.

4 fig newtons

serving

e. Idon’t know 2. The upper limit

the

nutrition

preferred

food

for endurance percentage

baked ofplain

quiz*

of

for energy (glycogen) athletes. Which food

calories

from

carbohy-

potato cooked

recommended

pasta

(without

for cholesterol

sauce)

intake

is 300

NUTRITION mg

per

these

day.

Most

foods

a.

2-oz

ofpeanut

b.

8-oz

ofwhole

c.

‘/4

d.

Americans

contains

the

most

eat

1 cup

total Gen

a. pound

in heme a.

that

Americans Which

tend food

fat provide

less than

30%

to eat approximately has

the

highest

40% percentage

tofu know

Oils

fats

and

composed

polyunsaturated

highest

percentage

a. coconut b.

is a particularly

good

source

of which

one

of the

V&M

A

corn

know

should

exercise.

Which

replacement

drink

a.

water-soluble blood.

fiber The

best

appear source

to help of this

lower type

“Sports

statements

lost during

exercise,

and afabout

Ath

ofweight

Drinks”

during,

following

are absorbed

more

efficiently

one liter than

c. of

Warm

water

is absorbed

faster

than

cool

water.

d. aandc e. Idon’t

know

bran

b. oat bran c. oatmeal d.

the

H&D

water.

H&D wheat

Most

of fluid before,

of the

is TRUE?

b.

protein

plenty

ONE

d.

fiberis:

oil contains

oil

a. For every kilogram offluid is required.

in the

fat?

oil

Athletes

8.

fluid

level

monounsaturated

Which

oil

peanut

c. iron

cholesterol

acids.

of monounsaturated

e. I don’t ter

calcium

e. I don’t know 5. Foods that contain

of saturated,

fatty

c. olive oil d.

nutrients?

are

and/or

cookies

b. vitamin

cereal

e. I don’t 7.

know

following

V&M

iron-fortified

d.

cheese

Spinach

iron?

oxygen is richest

b. red snapper

seeds

c. shortbread

697

6. The iron in blood, heme iron, is needed to transport to the working muscle. Which of the following foods

cake

Idon’t

TRIATHLETES

c. raisins

as fat.

sunflower

d. swiss

a.

of

butter

calories.

offat?

4.

Which

Gen

ice cream

calories

e.

amount.

lb lean hamburger

of their

b.

this

OF

milk

e. I don’t know 3. It is currently recommended ofthe

over

cholesterol?

PATTERNS

grapefruit

e. Idon’t know

Downloaded from https://academic.oup.com/ajcn/article-abstract/51/4/690/4695205 by Washington University School of Medicine Library user on 19 May 2018

Categories for individual questions and correct answers are in bold type. Gen, general nutrition information; H&D, health and disease; V&M, vitamins and minerals; and Ath, athletics. 4

given