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THE EFFECT OF MILK ON ATHLETIC

ENDURANCE PERFORMANCE
by
Ernest Leo Smedley
AN ABSTRACT

Submitted to the College of Education of Midhigan State
University of Agriculture and Applied Science
in partial fulfillment of the requirement
for the degree of

MASTER OF ARTS

Department of Health, Physical Education, and Recreation

Year 1959

mm W

 

ERNEST LEO SMEDLEY' ABSTRACT

THE EFFECT 0? MILK ON ATHLETIC ENDURANCE PERFORMANCE

ggatement of the Problem

It is an important Objective of researchers in the
Physical Education field to supply coadhes with valid infor-
mation concerning technical aspects of coaching. Since it
is usual for coaches to become very influential in shaping
athletic practices, it is desirable that correct information
should be available to them. Information concerning proper
diet is essential to prevent the elimination of sound dietary
items from training meals. This study proposes to investi-
gate the validity of claims that milk impairs athletic
performance. The study will test the effect of the inclusion
and exclusion of milk and milk products in the diet on

physical endurance.

gethodolggy

line Freshmen track candidates from Midhigan State
University participated in the experiment. Records were
kept on body weight, basal metabolism, energy metabolism,
and all-out-runs. The energy metabolism test was conducted
on the motor-driven treadmill at a speed of six miles per

hour at ”0" degrees grade. The all-out-runs were also

3
ERNEST LEO SHEDLEY ABSTRACT
conducted on the tread-mill at a speed of ten miles per hour
at 8.6 percent grade. For the all-out-run the subjects ran
to exhaustion. then their times were recorded in seconds.
An analysis of variance was computed on gross oxygen debt.

exercise oxygen intake, and all-out-runs.

Conclusions

1. The inclusion and exclusion of milk and milk
products in the diets did not affect the endurance performance
of either group. The evidence of the data presented indi-
cates that milk does not hinder or benefit endurance
performance.

2. The energy metabolism measures of gross oxygen
intake and debt are not significantly affected by the

inclusion or exclusion of milk or milk products in the diet.

THE EFFECT OF MILK 0N ATHLETIC

ENDURANCE PERFORMANCE

by

Ernest Leo Smedley

A THESIS

Submitted to the College of Education of Midhigan State
university of Agriculture and Applied Science
in partial fulfillment of the requirement
for the degree of

MASTER OF ARTS

Department of Health. Physical Education, and Recreation

Year 1959

ACKNOWLEDGEMENTS

The author wishes to extend his thanks to Dr. Wayne
Van Buss for his interest and guidance in the preparation
of this thesis.

Special thanks is also extended to Dr. Gale Mikles
for his encouragement, suggestions, and assistance throughout
the preparation of this paper. The‘writer is also indebted
to Mr. Rye LaBaw for his cooperation and assistance in
securing data for the study, and to Dr. Henry J. Hontoye for

his valuable suggestions.

TABLE OF CONTENTS

Chapter Page
I. INTRODUCTION . . . . . . . . . . . . . . . . 1
Purpose of the Study . . . . . . . . . . 2
II. REVIEW OF THE LITERATURE . . . . . . . . . . 4
III. METHODOLOGY . . . . . . . . . . . . . . . . 7
Measurements . . . . . . . . . . . . . . 7

IV. ANALYSIS AND PRESENTATION OF DATA . . . . . 10
”sults O O C O O O O O O O O O O O O O 10
V. SUMMARX. CONCLUSIONS, AND

RECOMMENDATIONS . . . . . . . . . . . . . 15

Summary . . . . . . . . . . . . . . . . 15
Conclusions . . . . . . . . . . . . . . . 15
Recommendations . . . . . . . . . . . . . 16

BIBLIOGRAPHY . . . . . .'. . . . . . . . . . . . . . 17

LIST OF TABLES

Table Page

I. ANALYSIS OF VARIANCE: ALLv-OUT-RUNS, EXERCISE OXYGEN

INTAKE,GROSSOXY@NDEBT............. 12

CHAPTER I

INTRODUCTION

The belief that drinking milk impairs performance is

quite common among athletic coaches. This belief is

usually based on one or more of the following contentions:

1.

Under the emotional tensions and strenuous
physical effort associated with athletic
competition, milk contributes to decreased
salivary gland activity called "cotton mouth“.1
When milk has been consumed within a few hours
before competition, it does not digest properly,
"curdles in the stomach,” with resulting inter-
ference with maximum performance.2
Milk in the athlete's diet raises the fat intake.
This results in a lower respiratory quotient

during athletic endeavor. The raised oxygen

 

l
R. M. Moose, "Does Milk Make Mucus?" California

Medicine.

68:31-32, January, 1948.

2R; E. Brogdon, P. A. Hellebrandt. "Investigations of
the Influence of Exercise Upon Digestion in the Stomach; The
Effect of swimming Upon the Acidity of the Gastric Juice,”
Research Quarterly, 5:52-62. May, l934.

requirement for a given amount of work pre-
vents the attainment of top endurance
performance.
Although we know of no scientific evidence to support
these contentions, we are also unaware of any controlled
experiments which indicate that milk is beneficial to

athletic performance.

‘ggggose of the Study

It is an important Objective of researdhers in the
Physical Education field to supply coaches with valid in-
formation concerning technical aspects of coaching. Since
it is usual for coaches to become very influential in shaping

4 it is desirable that correct information

athletic practice,
should be available to them. Information concerning proper
diet is essential to prevent the elimination of sound dietary
items from training meals.

This study proposes to investigate the validity of

claims that milk impairs athletic performance. The study will

 

E. H. Christensen, 0. Hansen, "Work Capacity and
Nutrition." Skardinavisches Archiv for Physiologie, 81:160-171.
1939.

4
W. M. Staton, "Vitamin Nutrition for School boy
Athletes,“ Scholasticquach, 21:52, September, 1951.

test the effect of the inclusion and exclusion of milk and

milk products in the diet on physical endurance.

CHAPTER II
REVIEW OF THE LITERATURE

In reviewing the literature concerning the relation-
ship between diet and physical efficiency, the writer was
unable to locate a scientific study dealing with milk and
athletic performance. The information gathered by the writer
does offer some light on the study and is presented in this
writing.

Dr. H. C.'Carlson5 stated that: ”Some superstitious
coaches believe that milk, a so—called "heavy food" is bad
for athletes."

In this article as well as many others milk is
referred to as being bad for athletes without scientific
evidence to support these statements. H. L. Upjohn6 and
others also referred to ”old wives tales” in reference to

athletes and milk.

 

SE. C. Carlson, "Care and Feeding of Athletes; A

Medical Report," Newsweek, 41”102, MarCh 23, 1953.

63. L. UpJOhn, J. A. Shea, P. J. Stare, and L. Little,
"Feeding the Athlete,“ Scholastic Coach, 23:36, September,
1953.

In 1938 Bohm7 in his "How Champions Train," reported

that Jehnny Kelly, an American Olympic contestant of 1936
made this statement: “I personally cannot stomach milk--
it makes me ill.“ In the same article Behm also reported
that Boyd Comstock, coadh of the 1936 Italian Olympic team
stated: "Mulk almost ruined one of my athletes and putting
him back on wine and water made him 0K.”

The writer believes that these statements may have
some bearing on the creation of the “old wives tales.“

In contrast to the previous statements G. Z. Dupain8
in his training diet for endurance performance, included four
cups of milk daily. Dupain stated that this was to prevent
a calcium deficiency. This is in agreement with Dr. Genevieve
Sterns,9 who stated: "American habits of diet make calcium
deficiency a common defect of nutrition in this country.”.

The 1953 edition of 129325 gealth10 stated: ”Unfor-

tunately, many food fads are followed by some of these who

 

7
w. Bohm, "How Champions Train," thletic Journal,
18:5, 1938.

8G. 2. Dupain, “Specific Diets and Athletic Fitness;

a Prelimary Investigation," Reseaggh Quarterly, 10:33-40,
December, 1939.

9
Dr. Genevieve Stearns. "Lack of Calcium is Common

Deficiency,” Science Digest, 27:51, May, 1950.

10" u ,
1953. Diet for Athletes, Todays Health, 31.4, February,

6
supervise diets of athletes. For example, some warn against
the use of fluid milk without knowing why and without
recognizing that milk is a good source of energy as well as
calcium.“

In relation to calcium deficiency, Steggerda and
Mitchell11 found'that milk and milk solids supplied three
fourths of the amount of calcium needed for body equilibrium.
Staten12 reported that milk is also an important source of
Vitamin A, 3-2, and D. With these facts in mind Lininger13
stated that: "The influence of the addition of milk to the
diet of school children is reflected in a definite increase

in the rate of growth,‘both in height and weight."

 

11
F. R. Steggerda, E. H. Mitdhell, ”Calcium Requirement

of Adult Man and Utilization of Calcium in Milk,” JOurnaligg
nutrition, 17:243-262. Mardh, 1939.

12w. M. Station, ”Role of Vitamins in Athletic
Performance," sgholasgig Coagh, 21:34, October, 1951.

13
P. P. Lininger, "Relation of the Use of Milk to the
Physical and scholastic Progress to Undernourished Sdhool
Children,“ American Journal'gg Public gealth, 23"555—60,
June, 1933.

CHAPTER III

METHODOLOGY

This study was undertaken to determine the relation-
ship of milk on athletic endurance performance. Nine
freshmen track men trained in endurance running were trained
for one month in running on the motor-driven tread mill.

They were then divided into two groups. One group of four
subjects consumed diets containing three pints of milk daily
and about two pints of ice cream per week. The other five
subjects consumed no fluid milk or milk products. The period

of observation was eight weeks.

Measurements
1. Basic measurements (repeated three times)
a. skin fold fat measurements
*b. blood serum cholesterol

c. diet history and diet recall (daily for one
week)

2. Daily measurements
a. body weight

b. basal metabolism (including respiratory
quotient)

 

*
Not necessary for experiment

c. electrocardiogram

d. energy metabolism during standardized steady
state. strenuous running on the tread mill
(measurements taken were instantaneous oxygen
intake, respiratory quotient during and after
the run, and oxygen debt.)

e. Two all-out runs per week under supervision.
The subjects ran on the motor driven tread
mill at a speed of 10 miles per hour at an
incline of 8.6 degrees.

The subjects ran to exhaustion and their times
recorded. The Dougless method of gas collection'was
utilized.14 For carbon dioxide analysis, samples were
collected over mercury in Bailey bottles. Carbon dioxide
was analyzed using the Haldane-Henderson apparatus. Oxygen
samples were taken from the Dougless bags in small rubber
.bags and analyzed immediately using a Beckmen E-2 Oxygen
Analyzer. Repeat cheeks were maintained on the Beckmen by
duplicate samples and Haldane analysis.

The steady state exercises were run on the Mbtor-
driven treadmill at a speed of six miles per hour at "0“
degrees grade. The all-out—runs were run at a speed of ten

miles per hour at 8.6 percent grade.

The variables selected for analysis in the present

 

14
K. Edam, ”Practical Direction for Determination of

Basal.Metabolism.According to Dougless-Haldane,” Medicus
Monatsschg, 7:791—796, December, 1953.

study were the exercise oxygen intake, gross oxygen debt,
15, 16, 17

and the all-out-runs. The analysis of variance

technique was used for statistical treatment of the data as

18
described by Goulden.

 

15
C. A. Knehr, D. B. D111, and W; Heufeld, ”Training

and Its Effect on Man at Rest and At Wor ," American gournal
Physiolggy, 136-148-156, 1942.

16:21d.
17

H. L. Taylor, E. Buskule, and A. Henschel, "Maximal
Oxygen Intake as an Objective Measure of Cardiorespiratory

Performance," gouggal.gg.Applied Physiology, 8:73-80,
July, 1955.

18
C. H. Goulden. Methods 9; Statistical Analysis.
new Yerk: John Wiley and Sons, Inc., 1952. p. 93.

CHAPTER IV
ANALYSIS AND PRESENTATION OF DATA

This study was undertaken in an effort to determine
differences in athletic performance that could be attributed
to the inclusion or exclusion of milk and milk products from

the diet. The subjects were tested over an eight week period.

Results

Analysis of variance was used in the statistical
analysis according to Goulden. The difference between the
groups, weeks, individuals, and the groups' x weeks inter-
action were all tested. Since the experimental and control
groups were formed by the random placement of subjects into
the two groups (the groups were not evenly matdhed in the
size sample used) a correct interpretation of these analyses
is essential.

A statistically significant "E"‘between the two groups
indicates either that the groups were different to start
with, that the groups responded differently to the training,
or that a combination of the two took place. The groups x

the weeks interaction reflects the difference in the slopes

ll
of the training curve of the two groups. If the response to
training is different this interaction should be significant.
The groups x weeks interaction is the critical statistic.
in this experiment due to the initial difference in groups in
most of the variables. Therefore if the group statistic is
significant and the difference is to be attributed to the
experimental variable the groups x weeks interaction must
also be significant. If it is not, the significance in the
group statistics is attributable only to the initial differ-
ence in the groups. The weeks statistics reflect the changes
taking place in both groups with training. Where signifi-
cant,it merely means that the changes are not chance
fluctuations but are real differences. The individual
statistics were calculated because the individuals are
different. The difference due to training, as the experi-
mental variable, would necessarily have to be large. Pulling
out the individual's variance permits a better examination
of the experimental variable. The fact that all of the
individuals’statistics were significant confirms this logic.

The all—out runs were used as one measure of athletic
endurance performance. The subjects ran on the motor-driven
tread-mill at a speed of ten miles per hour at an incline of

8.6 degrees. The subjects ran to exhaustion and their times

12
were recorded.

Table I contains the analysis of variance results for
the all-out-runs. The groups, weeks, and the individual's
statistics were statistically significant at the .01 level.
The groups "F“ may be accounted for by the fact that the
subjects were not evenly matched at the start. The effect
of the diet's (group x weeks) shows no statistical sig-
nificance with an "F" of .57. An "F" of 7.31 is needed to
be significant at the .01 level. The "F" values for the
individuals were very high in all of the analyses. This may
be attributed to differences in the levels of athletic

abilities of the subjects tested.

TABLE I

ANALYSIS OF VARIANCE OF GROSS OXYGEN DEBT, EXERCISE OXYGEN
INTAKE, AND ALL-OUT-RUNS

 

 

 

 

 

Gross Oxygen Exercise Oxygen All-Out
* ert Intake Rugs

Groups .16 2.25 l9.41**
Weeks 1.57 1.75 7.48**
Individuals 12.81** 11.0** 105.27**
Groups x Weeks .60 1.25 .57

"p = .01

'k

subtracted degrees of freedom according to W. P. Eaten,
"Formulas for Finding Estimates For Two and Three Missing
Plots in Randomized Block Layouts," Midhigan State College
Agricultural Experiment Station, Technical Bulletin 165, April,
1939.

13

The exercise oxygen intakes were used as a measure
of the athlete's ability to pull oxygen (needed for endurance
performance) out of the air.

Table I contains the analysis of variance for the
exercise oxygen intake. Again it was found that the indi-
viduals were significant at the .01 percent level, with an
"F" of 11.0. Here we also find that the effect of the diets
(group x weeks) shows no statistical significance with an
“E" of 1.25.

The gross oxygen debt was used as another measure of
athletic endurance performance. Table I contains the analysis
of variance for the gross oxygen debt. Again it was found
that the individuals were statistically significant at the
.01 percent level with an "F“ of 12.81. The effect of the
diets however (group x Weeks) was not statistically signifi-
cant.

The following Observations may be made relative to the
analysis of variance of the three variables.

The individual's statistics were all significant at
the .01 percent level of confidence. This suggests that the
individuals are different in their athletic endurance per-
formance capacities. In no case did the author find

statistical significance in the milk and non-milk diets.

CHAPTER V

SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

SW85!

Nine freshmen track candidates were selected from the
Michigan State University freshmen track team to participate
in this experiment. The purpose of the study was to determine
the relationship of the inclusion and exclusion of milk and

milk products in the diet on physical endurance performance.

Conclusions

The following conclusions seem justified on the
basis of the statistical data presented.

1. The inclusion and exclusion of milk and milk
products in the diets did not affect the all-out endurance
performance of either group. .Milk does not hinder endurance
performance, however the evidence presented also does not
indicate that milk is beneficial to athletic endurance per-
formance. ‘

2. The energy metabolism measures of gross oxygen
intake and debt are not significantly affected by the

inclusion or exclusion of milk and milk products in the diet.

16

Recommendations

The following recommendations are made as a result
of this study.

1. A similar investigation using a large number of
high school subjects may give more light on the subject.

2. A study on the psychology of endurance running
may give us more insight on this important aspect of
training.

3. A study involving the overload principle of
training using a motor-driven tread-mill as the training

device might prove to be invaluable to coaches.

BIBLIOGRAPHY

A. BOOKS

C. H. Goulden. Methods'gf Statistical Analyses. NEW york:
JOhn Wiley and Sons, Inc., 1952. p. 93.

B. PERIODICALS

Bohm, W. "How Champions Train," Athletig gournal, 18:5,
1938.

Brogdon, R. E., Hellebrandt, P. A. ”Investigations of the
Influence of Exercise Upon Digestion in the Stomach;
The Effect of Swimming Upon the Acidity of the Gastric
Juice," Research Quarterly, 5:52-62, May, 1934.

Daniels, A. L. "Relation of Milk Ingestion to Calcium

Metabolism," Society f0; Experimental‘giglggy and
.Medicine, Proceedings, 30:1062-1063, 1933.

Christensen, E. H., Hansen, 0.. ”Work Capacity and

Nutrition, " Skandigavisges $9111! £91 W,
81:160-171. 1939.

Christensen, E. H., Hogberg, P. ”Steady State, 02 Deficit
and 02 Debt at Severe work,” Arbeitsphysiolggie,
14:251-254. 1950.

Dupain, G. 2., ”Specific Diets and Athletic Fitness, A
Preliminary Investigation," Research Quarterly,
10:33-40, December, 1939.

Knehr, C. A., Dill, D. 3., Neufeld, W; "Training and Its
Effect on Man at Work and At Rest," American Journal
Physiolggy, 136:148-156, 1942.

Lininger, P. P. “Relation of the Use of Milk to the Physical
and Scholastic Progress of Undernourished School
Children," American gournal‘gg Public fiealth, 23:555-60,
June, 1933.

18

Miller, A. T., Blyth, C. 8. "Influence of Body Type and
Body Fat content on Metabolic Cost of Work," Journal
‘2; Applied Physiology, 8:139-141, September, 1955.

Moose, R. M. "Does Milk Make Mucus?" California Medicine,
' 68:31-32, January, 1948.

Rosenberg, L. C., Rogers. F. R. "Study of the Effect of Two
Diets on Physical Powers," Research Quarterly,
6:257-62, March, 1935.

Sperling, G. "Effect of Long Time Feeding of Whole Milk to
White Rats," Journal.p§ Nutrition, 55:399-414, March,
1955. . *

Stearns, G. "Lack of Calcium Is Common Deficiency,“ Science
Digest, 27:51, May, 1950.

Staton, W. M. "Vitamin Nutrition for school Boy Athletics,”
Scholastic goach, 21:52, September, 1951.

Staton, W; M. "Role of Vitamins in Athletic Performance."
Scholastic goach, 21:34, Octcber, 1951.

Steggerda, F. R., Mitchell, H. H. "Calcium.Requirements of
Adult Men and Utilization of Calcium.in Milk," Jouppal
[pg Nptrition, 17:253-262. March, 1939.

Taylor, H. L., Buskul, E., Henschel, A. “Maximal Oxygen
Intake as Objective Measures of Cardiorespiratory

Performance," gourna1.g§ Applied Physiology, 8:73-80,
July, 1955.

Uijhn, H. L., J. A. Shea, F. J. Stare, and L. Little.
"Feeding the Athlete,” Scholastic Coach, 23:36,
September, 1953.

Uijhn, H. L., J. A. Shea, F. J. Stare, and L. Little.
."Nutrition of Athletes: Council on Foods and Nutrition,"
Journal'pg Egg American Medical Association, 151:818-819,
MarCh, 1953.

19
C. ARTICLES
Carlson, H. C. ”Care and Feeding of Athletes; A Medical
Report,” Newsweek, 4l"102, March 23, 1953.
Chittenden, R. H. ”Influence of Diet on Endurance and
General Efficiency," Popular Science, 71:536-41,
December, 1907.

“Diet for Today's Athletes," Todays
Health, 31:4, February, 1953.

 

 

 

 

 

 

 

 

 

 

 

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