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Effect of Caffeine on Golf Performance and
Fatigue during a Competitive Tournament
PETEY W. MUMFORD
1
, AARON C. TRIBBY
2
, CHRISTOPHER N. POOLE
3
, VINCENT J. DALBO
4
,
AARON T. SCANLAN
4
, JORDAN R. MOON
5
, MICHAEL D. ROBERTS
1
, and KAELIN C. YOUNG
1,6
1
Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL;
2
Department of Human
Performance Studies, Wichita State University, Wichita, KS;
3
Department of Applied Physiology and Wellness, Southern
Methodist University, Dallas, TX;
4
School of Medical and Applied Sciences, Central Queensland University, Rockhampton,
Queensland, AUSTRALIA;
5
MusclePharm Sport Science Institute, Denver, CO; and
6
Department of Cell Biology and
Physiology, Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, AL
ABSTRACT
MUMFORD, P. W., A. C. TRIBBY, C. N. POOLE, V. J. DALBO,A. T. SCANLAN, J. R. MOON, M. D. ROBERTS, and K. C. YOUNG.
Effect of Caffeine on Golf Performance and Fatigue during a Competitive Tournament. Med. Sci. Sports Exerc., Vol. 48, No. 1, pp. 132–138,
2016. Purpose: This study aimed to determine the effect of a caffeine-containing supplement on golf-specific performance and fatigue
during a 36-hole competitive golf tournament. Methods: Twelve male golfers (34.8 T13.9 yr, 175.9 T9.3 cm, 81.23 T13.14 kg) with a
United States Golf Association handicap of 3–10 participated in a double-blind, placebo-controlled, crossover design in which they
played an 18-hole round of golf on two consecutive days (36-hole tournament) and were randomly assigned to consume a caffeine-
containing supplement (CAF) or placebo (PLA). CAF/PLA was consumed before and after nine holes during each 18-hole round.
Total score, drive distance, fairways and greens in regulation, first putt distance, HR, breathing rate, peak trunk acceleration, and trunk
posture while putting were recorded. Self-perceived ratings of energy, fatigue, alertness and concentration were also recorded.
Results: Total score (76.9 T8.1 vs 79.4 T9.1, P= 0.039), greens in regulation (8.6 T3.3 vs 6.9 T4.6, P= 0.035), and drive distance
(239.9 T33.8 vs 233.2 T32.4, P= 0.047) were statistically better during the CAF condition compared with those during PLA.
Statistically significant main effects for condition (PG0.05) and time (PG0.001) occurred for perceived feelings of energy and
fatigue. Compared with PLA, CAF reported more energy (P= 0.025) and less fatigue (P= 0.05) over the competitive round of golf.
There were no substantial differences in HR or breathing rates, peak trunk acceleration, or putting posture between conditions or over
the round (P90.05). Conclusions: A moderate dose (1.9 T0.3 mgIkg
j1
) of caffeine consumed before and during a round of golf
improves golf-specific measures of performance and reduces fatigue in skilled golfers. Key Words: NUTRITION, GOLFERS,
ENERGY, ACCURACY
Golf is a popular sport around the world with in-
dividuals playing competitively and recreationally.
When played competitively, golf involves high
cognitive loads, critical shot-making decisions, hand–eye
coordination, high-level motor and biomechanical skill, and
an extended duration of play that exceeds most other sports
(28). From an intensity perspective, the physiological de-
mands of golf are considered low, with one round of 18
holes taking approximately 4 h to complete and having an
energy expenditure of 4.3–4.5 METs (1,11). However, one
round of golf can result in walking well over 10,000 steps
covering distances over 8000 m (13). Furthermore, com-
petitive golf settings include preround warm-ups, practice
swings, and execution of in-round swings. During an 18-hole
round, swinging a golf club will be repeated, on average,
50 times and over 300 times during a practice session (30).
This combination of critical shot-making decisions, multiple
maximum effort swings, putting, and long distances of walk-
ing during the round can result in physical and mental fatigue,
which can potentially have a negative effect on golf perfor-
mance (9,29). Specifically, mental fatigue may affect the
ability to select the correct club, shot type, and execution of
the golf shot (28), whereas physical fatigue may affect the
mechanics of the golf swing (14). Therefore, competitive
golfers may benefit from preround and in-round nutritional
and supplementation strategies aimed at offsetting fatigue
experienced during a competitive round of golf (13).
Because caffeine has psychological and physiological
effects, it has become one of the most consumed ergogenic
aids to date (3). Indeed, Del Coso et al. (8) reported that
74% of the 20,686 elite athletes sampled between years
2004 and 2008 were found to consume caffeine either be-
fore or during competition. Furthermore, consuming mod-
erate doses of caffeine either 1 h before or throughout the
cycling exercise has been shown to enhance performance
and improve time to fatigue (7,20). The ergogenic benefits
Address for correspondence: Kaelin C. Young, Ph.D., Edward Via College
of Osteopathic Medicine, Auburn Campus, 910 S. Donahue Dr., Auburn,
AL 36832; E-mail: kyoung@auburn.vcom.edu.
Submitted for publication April 2015.
Accepted for publication July 2015.
0195-9131/16/4801-0132/0
MEDICINE & SCIENCE IN SPORTS & EXERCISE
Ò
Copyright Ó2015 by the American College of Sports Medicine
DOI: 10.1249/MSS.0000000000000753
132
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of caffeine are not restricted solely to physical performance
outcomes because several studies support its effectiveness
of enhancing cognitive ability during mentally (19) and
physically fatiguing tasks (19,27). For instance, in situa-
tions where fatigue is forced such as in sleep deprivation
studies, moderate doses of caffeine have been shown to
reduce fatigue during short-term vigilance tasks (32). There-
fore, caffeine may play an important role in performance
outcomes during periods of increased cognitive demand, re-
action time, and when technical/tactical skills have a major
influence on physical and mental performance (15,33). To
our knowledge, only one study has previously attempted to
determine the effects of caffeine supplementation on golf
performance. Stevenson et al. (29) determined the acute
effects of a caffeine and glucose drink on golf performance
in a laboratory setting to simulate competitive golf course
play (29). Their findings suggested that consuming a combi-
nation of glucose and caffeine was beneficial for minimizing
fatigue and improving golf performance. However, there is
a lack of research on overall golf performance in a true
competitive tournament setting. Therefore, the purpose of
this study was to investigate the acute effects of a caffeine-
containing nutritional supplement on golf performance and
fatigue during a competitive 36-hole tournament.
METHODS
Subjects. A convenience sample of 12 male golfers
(Table 1) were recruited from local golf courses, newspaper
advertisements, and the local university campus. Participants
were included if they were habitual caffeine consumers (35–
300 mgId
j1
), had a United State Golf Association (USGA)
handicap between 3 and 10, were between 20 and 55 yr of
age, free of known cardiovascular, respiratory, metabolic, or
musculoskeletal ailments, and were not taking any other pur-
ported performance-enhancing supplements/ergogenic aids.
After ethical approval from the institutional review board,
participants were informed of all experimental procedures, read
and signed informed consent forms, and filled out medical
history forms detailing caffeine use and golf playing history.
Experimental protocol. In a double-blind, placebo-
controlled, crossover design, participants played an 18-hole
round of golf on two consecutive days (36-hole tournament).
A simple randomization procedure was used to assign par-
ticipants to consume a caffeine-containing supplement
(CAF) or placebo (PLA) during each 18-hole round. Par-
ticipants reported to the human performance laboratory 1 wk
before their first round of golf for anthropometric and
physiological assessments. During this visit, participants
were familiarized with tournament procedures and USGA
rules. The tournament was conducted at the local university
golf course where tee box markers and hole locations were
held constant. To ensure a competitive setting, a $1000
purse provided by the researchers was awarded to partici-
pants on the basis of the place finished in the 36-hole tour-
nament. Participants were allowed to use their own golf
equipment (clubs/golf balls) but were restricted to remain
consistent between 18-hole rounds. The brands/models of
golf equipment were documented before the start of the
tournament, and adherence was ensured by researchers be-
fore the start of each round. Importantly, each participant
had previously played a round of golf on the golf course.
On the day of each round, participants were informed to
abstain from consuming any foods, drinks, or nutritional
products containing caffeine, to arrive hydrated, and to have
consumed a meal 2 h before. Participants were asked to
follow the same procedures for the second day including
consumption of the same meal. Upon arriving, participants
produced a urine sample, were fit with a mobile physiolog-
ical monitoring device, and rested in a seated position for
10 min for collection of resting data. Afterwards, partici-
pants assigned to the CAF or PLA group consumed their
first dose and were driven to the driving range where they
were allowed 10 min to hit 20 golf balls and were not re-
stricted to swinging specific clubs. Once completed, partic-
ipants were taken to a practice hole for an iron club accuracy
assessment. The time that elapsed between the first CAF or
PLA oral dose and the accuracy assessment was approxi-
mately 25–35 min. This time course was maintained to al-
low caffeine levels to reach peak plasma concentration (4).
After the assessment, participants were driven to the first tee
box by a research assistant who collected in-round golf data
and transported golf clubs via a golf cart. Participants then
completed an energy/mood status questionnaire and began
their round of golf thereafter. Participants walked the entire
tournament and had access to chilled water bottles ad libitum.
After completion of the first nine holes, participants con-
sumed a second dose of CAF/PLA, were provided a stan-
dardized meal aimed at offsetting the decline in blood
glucose levels (13), and completed a second questionnaire.
Upon completion of the round, participants completed the
final questionnaire, physiological monitors were turned off
and collected, and participants were debriefed and reminded
of the procedures for the following day/round. See Figure 1
for an overview of the protocol.
Anthropometric and physiological assessment.
Standing height was measured to the nearest 0.5 cm using a
calibrated stadiometer. Body mass was measured with a
calibrated clinical scale to the nearest 0.01 kg with partici-
pants wearing minimal clothing (Table 1). After resting
quietly, systolic and diastolic brachial blood pressure and
HR were measured using an automatic blood pressure cuff
(model HEM-773; Omron, Vernon Hills, IL) in a seated
position. Urine samples were collected for determination of
TABLE 1. Baseline male subject characteristics (mean TSD).
n=12
Height (m) 1.76 T0.09
Weight (kg) 81.2 T13.1
Age (yr) 34.8 T13.9
BMI (kgIm
j2
) 26.3 T3.6
USGA handicap 5.5 T2.7
Caffeine intake (mgId
j1
) 101.7 T59.8
BMI, body mass index.
CAFFEINE AND GOLF PERFORMANCE Medicine & Science in Sports & Exercise
d
133
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hydration status via urine specific gravity (USG) with a
handheld refractometer (model CLX-1, precision = 0.001 T
0.001; VEE GEE Scientific, Inc.). A USG reading between
1.000 and 1.029 was considered adequately hydrated (5). If
participants had a USG reading at or above 1.030, they were
instructed to drink water and rest comfortably until a second
urine sample could be provided. Hydration was assessed as a
precautionary measure to ensure participants_safety and to
minimize the effects of dehydration on performance.
Environmental conditions. Ambient temperature (-C),
relative humidity (%), wind speed (kmIh
j1
), and direction
during each round were documented in 30-min intervals.
Data was provided by the Wichita division of the National
Oceanic and Atmospheric Administration from weather sen-
sors located near the golf course.
Five-ball iron club accuracy assessment. On a
100.5-m practice hole, participants were allowed eight at-
tempts to land the golf ball as close to the hole as possible.
The first three attempts were for practice, and the last five were
measured. Once the golf ball came to rest, distance (m) from the
front of the ball to the middle of the hole and whether the ball
rested on the green (# balls) were measured and documented.
Distances were measured using a 92-m industrial tape measure.
Participants chose a club of their choice but maintained the use
of this club on both days. Furthermore, the same golf balls were
used each day, which were provided by researchers.
Drive and putt distance. Drive distance (m) (when
a driver club was used) was measured using a SkyCaddie
LINX GPS device (SkyHawke Technologies, LLC,
Ridgeland, MS). Once participants placed the tee and ball
into the ground of the tee box, the location was marked with
the GPS by standing directly over the ball, waiting 3 s, and
then marked using the device_s ‘‘mark ball’’ function. After
the tee shot, the resting location of the ball was identified;
the device was then held over the top of the ball for three
seconds and ‘‘marked’’ again. The distance between the two
locations was displayed on the device and documented
by researchers. Intra- and interdevice test–retest reliability was
previously determined on the same golf course from 15 dis-
tances measured twice and computed using intraclass corre-
lation coefficients (ICC), SEM, and minimal difference (MD)
to be considered real. Intradevice measurements resulted in an
ICC of 0.999, SEM of 0.73 m, and MD of 2.02 m, whereas
interdevice measurements resulted in an ICC of 0.997, SEM
of 1.92 m, and MD of 5.32 m. On the basis of this analysis,
each participant was assigned their own GPS, which was used
for both rounds. All first putt attempts were measured for
distance (m) from the front of the ball to the middle of the
hole with a 92-m industrial tape measure. Care was taken to
ensure that the tape was straight, taut, and laid flat against
the putting surface.
Physiological and accelerometry measures. HR
(bpm), breathing rate (BR, breaths per minute), trunk posture
(POS (-)), and peak trunk acceleration (ACC
peak
(g)) were
determined using the Zephyr Bioharness
TM
3 (Zephyr
Technology, Annapolis, MD). The device was worn just
beneath the chest across the sternum and secured with an
elastic nylon strap with extra support provided by a shoulder
strap. The monitoring device is secured to the chest strap and
acts as a transmitter and data logger. The device uses a pie-
zoelectric triaxial accelerometer, electrode, and pressure
sensors within the strap. The validity and reliability of this
device have been described previously (HR: r=0.61,PG
0.01; BR: r=0.67,PG0.01; ACC: r=0.90,PG0.01) (17).
Specifically, trunk POS immediately before putting was
assessed during the first and last three holes of each round.
Trunk ACC
peak
was assessed on all holes only when the
FIGURE 1—Overview of experimental protocol on the day of each
round.
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driver club was used. Data were logged, time-stamped, and
exported to Microsoft Excel (Microsoft, Redmond, WA)
immediately after each round for subsequent analysis. To
minimize interdevice error (17), all participants were
assigned their own Bioharness device, which was used for
both rounds (Table 1).
Golf-specific performance. Total score (number of
strokes to complete 18 holes), putts per round, fairways hit
in regulation (FIR, defined as the ball lying in the fairway
after a tee shot on a par 4 or 5 hole), greens hit in regulation
(GIR, defined as the ball lying on the surface of the green
after the tee shot on a par 3, after the second shot on a par 4,
or after the third shot on a par 5 hole), sand shots (defined as
a ball being hit into a sand bunker), sand save percentage
(SS%, defined as the percentage of time a golfer success-
fully hits the ball onto the green from a bunker and makes
the following putt to save par), and shots hit out of bounds
(OB, defined as a ball being hit out of the field of play
resulting in a penalty stroke) were documented by research
staff following participants throughout both rounds.
Energy/mood questionnaire. A five-item visual an-
alog scale questionnaire previously used in caffeine research
and partly adapted from Rogers et al. (26) was used to assess
self-perceived feelings of concentration, energy, fatigue,
alertness, and overall confidence. Each mood state/feeling
was followed by a 100-mm horizontal line with vertical
lines anchored at each end. The left-end anchor was labeled
‘‘Very Low,’’ and the right anchor was labeled ‘‘Very High.’’
Participants were instructed to make a vertical mark through
the line on the basis of how they felt at that moment. Re-
sponses were measured in millimeters (0–100) starting at
the left anchor of the scale. The questionnaire was admin-
istered at the beginning of each round (pre), after the ninth
hole (mid), and after the 18th hole (post).
Supplementation/in-round nutrition. Caffeine (CAF,
155 mg) was provided in two forms: raw caffeine and
PURENERGY
Ò
(caffeine and pterostilbene; ChromaDex,
Inc., Irvine, CA) in a multi-ingredient proprietary blend sup-
plement in a purified water-based medium containing vitamin B
complex, citric acid, elevATP
Ò
(VDF FutureCeuticals Inc.,
Momence, IL) and sucralose. PLA was provided in a similar
purified water-based medium matched for color and consis-
tency but containing only sucralose to match flavor profile. To
maintain blinding, both CAF and PLA were delivered directly
from the third-party manufacturer (BioZone Laboratories, Inc.,
Pittsburg, CA) in unmarked black and white plastic vials
containing a single 2-mL serving. Vials were administered
to participants before each round of golf and after the ninth
hole. A second dose was given because of the half-life of
caffeine and the lengthy play of golf (2). After consuming
the second vial of CAF or PLA, a standardized meal pro-
viding340calories,42gofCHO,12goffat,and24gof
protein was provided in the form of two off-the-shelf meal
replacement bars. After data analysis and drafting of the
final report, researchers were notified by the manufacturer
which color vials were the CAF and PLA.
Statistical analysis. Data are reported as mean TSD
for all dependent variables. Statistical analyses were per-
formed using SPSS for Windows version 21.0 (IBM,
Seattle, WA). Before analysis, the distributional proper-
ties of each dependent variable were tested for normality
using the Kolmogorov–Smirnov procedure, with an alpha
level of 0.05. Mean differences between conditions for
all dependent golf-specific performance variables were ex-
amined using paired-samples t-tests. Dependent variables
from the self-perceived mood and energy questionnaire
were assessed using a 2 3 (condition time) factorial
ANOVA. Physiological and accelerometry data were ana-
lyzed using a 2 2 (condition time) factorial ANOVA.
If a significant interaction effect was found, follow-up analysis
included one-way ANOVA with repeated measures and
paired-samples t-tests with Bonferroni corrections. Statis-
tical significance for all null hypothesis testing was set at
Pe0.05. Furthermore, magnitude of the effect was calcu-
lated using the formula for the Cohen d effect size: (CAF
mean jPLA mean)/pooled SD) for all performance vari-
ables with observed effects as well as 95% confidence in-
tervals (CI) for the mean difference between conditions.
Effect sizes of 0.2, 0.5, and Q0.8 were considered small,
moderate, and large, respectively.
RESULTS
Baseline subject characteristics are presented in Table 1.
Mean ambient temperature (36.6-CT0.8-C vs 36.7-CT
0.5-C), wind direction and speed (south 32.1 T5.6 kmIh
j1
vs
south 30.9 T4.6 kmIh
j1
), and humidity (24.3% vs 28.7%)
were similar (P90.05) between rounds 1 and 2, respectively.
Under the CAF condition, mean relative CAF intake was
3.8 T0.6 mgIkg
j1
of body mass over the entire round.
Furthermore, there was no substantial difference (P90.05)
between conditions for total water intake (CAF vs PLA,
2.21 T0.44 L vs 2.12 T0.45 L) or preround USG (1.016 T
0.006 vs 1.018 T0.006).
Iron club accuracy assessment. The mean number
of balls on the green and distance to the hole for each con-
dition is presented in Table 2. Both the number of balls on
the green (mean difference (95% CI), 1.08 (0.34–1.82); P=
0.008; ES, 0.86) and distance left to the hole (j2.42 m
(j3.95 to j0.88); P= 0.005; ES, 1.00) were statistically
better under the CAF condition compared with those in
the PLA, with the mean differences between conditions
resulting in large and meaningful effects.
Golf-specific performance. There were no substan-
tial differences in the number of FIR, putts/round, shots hit
OB, sand shots, SS%, or first putt distance between con-
ditions (Table 2). However, total score (j2.50 (j4.85 to
j0.15) strokes; P= 0.039; ES, 0.3), GIR (1.75 (0.14–
3.36); P= 0.035; ES, 0.4), and drive distance (6.70 m
(0.10–13.31); P= 0.047; ES, 0.2) were statistically better
under the CAF condition compared with those under the
PLA condition.
CAFFEINE AND GOLF PERFORMANCE Medicine & Science in Sports & Exercise
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Physiological and accelerometry data. Average
HR and BR over the entire round under the CAF condition
was 120.0 T21 bpm and 19.0 T2.7 breaths per minute,
respectively, and 117.0 T14.0 bpm and 20.0 T2.0 breaths
per minute for the PLA condition, with no substantial dif-
ference between conditions (P90.05). Neither trunk posture
while putting nor peak trunk acceleration while hitting a
driver changed substantially over the round (front nine holes
vs back nine holes) or between conditions (Table 3).
Mood and energy state questionnaire. There were
no statistically significant condition–time interactions for
self-perceived ratings of alertness (P= 0.77), overall confi-
dence (P= 0.06), or concentration (P= 0.64). However, a
significant main effect for condition (P= 0.047) and time
(PG0.001) was detected for self-perceived ratings of ‘‘en-
ergy’’ (Table 4). Follow-up analyses revealed that energy
declined after 18 holes of golf compared with baseline for
both conditions, but the CAF condition maintained greater
feelings of energy after nine holes (mid) compared with PLA
(9.58 (1.44–17.73) mm; P= 0.025; ES, 0.5). Furthermore,
a statistically significant (P= 0.045) condition–time in-
teractions effect occurred for self-perceived ratings of fa-
tigue. Post hoc analysis revealed that fatigue increased over
the PLA round but did not substantially change from base-
line during the CAF round (Table 4). Lastly, golfers expe-
rienced less fatigue under the CAF condition compared with
during the PLA condition after nine holes (j13.42 mm
(j26.82 to j0.14); P= 0.05; ES, 0.6).
DISCUSSION
The objective of this study was to determine the effect of
a caffeine-containing supplement on golf performance and
fatigue in a competitive tournament setting. Our findings
suggest that acute consumption of a caffeine-containing sup-
plement taken before and during a round of golf 1) attenuates
self-perceived ratings of fatigue and sustains ratings of energy
compared with a placebo and 2) improves measures of golf-
specific performance.
Typically, golf is perceived as a nonfatiguing sport
because of the low physiological intensity at which it is
played. However, laboratory-based (29) and on-course
investigations (9) have found evidence of golf-specific fa-
tigue. Specifically, Doan et al. (9) reported an increase in
mental and physical fatigue in the latter half of a competi-
tive golf tournament in collegiate male golfers. Similarly,
Stevenson et al. (29) reported a significant decrease in mea-
sures of energy as well as a significant increase in mental
fatigue from a laboratory-based simulated round of golf. Our
findings support these results, as we found a decline in mea-
sures of energy and an increase in the perception of fatigue
throughout a competitive round of golf. However, caffeine
supplementation was able to significantly attenuate fatigue
during the round, which may have contributed to our findings
of improved measures of golf performance. Fatigue has been
shown to affect both physical and cognitive performance,
especially when cognitive tests are performed during or after
physically fatiguing exercise (21). Because competitive golf
demands a high level of cognitive and motor performance to
be successful, fatigue may negatively affect golf performance
through both central and peripheral mechanisms. The fatigue-
delaying effects of caffeine are well-known. Caffeine acts as
a CNS stimulant mainly by its interactions with adenosine
receptors functioning as a receptor antagonist, leading to
increased excitability of neuronal tissue, level of arousal,
and cognition (10,22). Along these lines, consumption of
moderate doses (100–300 mg) of caffeine has been shown
to positively affect cognitive and motor performance dur-
ing physically fatiguing tasks (15,31). Our data suggest that
a moderate dose of caffeine reduces golf-specific fatigue,
which seems to translate to improved accuracy and overall
golf performance.
TABLE 2. Golf-specific measures of performance for each condition (mean TSD).
PLA CAF P
Iron accuracy assessment
Balls on green (n) 1.75 2.83 0.008
Distance to hole (m) 7.84 5.42 0.005
In-round
FIR (n)4.7T2.0 5.3 T2.0 0.31
Putts per round (n) 33.4 T3.2 32.6 T4.7 0.49
Putt distance (m) 5.81 T0.86 5.58 T1.21 0.59
OB (n)0.7T1.2 0.2 T0.4 0.11
Sand shots (n)1.0T0.9 1.2 T1.0 0.50
SS% 25.0 T45.2 26.4 T41.1 0.67
GIR (n)6.9T4.6 8.7 T3.4 0.035
Drive distance (m) 233.3 T32.5 239.9 T33.8 0.047
Total score (strokes) 79.4 T9.1 76.9 T8.1 0.039
TABLE 3. Trunk posture while putting and peak trunk acceleration while swinging
(mean TSD).
Condition Front Nine Back Nine P
Posture (-) PLA 36.5 T7.0 36.9 T7.7 Condition, 0.20
CAF 34.9 T7.5 33.3 T5.3 Time, 0.43
Condition time, 0.54
ACC
peak
(g) PLA 3.6 T1.0 3.7 T1.0 Condition, 0.22
CAF 3.6 T1.0 3.5 T1.0 Time, 0.88
Condition time, 0.15
TABLE 4. Self-perceived ratings of energyand mood questionnaire for each condition
(mean TSD).
PLA CAF
Energy
Pre 63.8 T20.6 66.4 T19.1
Mid 53.2 T20.4 62.8 T20.9*
Post 42.2 T23.1** 49.8 T17.7**
Fatigue
Pre 24.8 T14.5 30.5 T20.6
Mid 47.7 T22.6 34.3 T22.3
Post 46.4 T21.9 43.3 T21.9
Concentration
Pre 67.8 T22.1 64.1 T24.1
Mid 57.8 T20.1** 59.9 T22.6*
Post 49.2 T20.5** 52.8 T18.9
Alertness
Pre 70.2 T20.0 67.8 T19.7
Mid 59.9 T20.0 61.6 T22.1
Post 56.7 T20.5 54.2 T16.7
Overall confidence
Pre 70.4 T14.5 67.9 T18.3
Mid 63.1 T17.5 59.8 T15.2
Post 52.6 T21.3 62.4 T14.5
*Significantly different from PLA, Pe0.05.
**Significantly different from pre, Pe0.05.
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There are limited original nutritional investigations aimed
at improving golf performance. To our knowledge, this is
the first study to attempt such a task in a competitive tour-
nament setting using skilled golfers. Stevenson et al. (29)
sought to determine the effects of a CHO and caffeine sport
drink on golf performance. Similar to our findings, they
reported improvements of accuracy under the condition and
a time effect for increases in measures of fatigue. However,
unlike our findings, the sports drink failed to attenuate the
fatigue response. These conflicting results may be from
methodological differences, as caffeine doses in our study
were almost twofold higher (29). Because of the metabolic
clearance rate of caffeine in humans, we chose to have par-
ticipants consume a second dose of the caffeine-containing
supplement after the first nine holes with an aim to maintain
blood caffeine levels over the entire round (4+ h). Moreover,
we observed improvements in iron club accuracy from
supplementation, whereas Stevenson et al. (29) reported
improvements in putting accuracy. We did not see im-
provements in putting, and the methodological differences
between studies render it incapable of adequate comparison.
Specifically, Stevenson et al. (29) used the same synthetic
surface at fixed distances (2 and 5 m) for putting assess-
ments for all 18 holes, whereas we used true grass multi-
farious putting greens on the golf course. Nevertheless, our
findingofimprovedironclubaccuracyissubstantial
because of the importance of iron club play. Recently,
Robertson et al. (25) reported that iron shot accuracy, on
approach shots to the green, was a significant predictor of
overall golf performance in a competitive tournament
setting. Therefore, caffeine, at doses used in this study,
has the ability to minimize golf-specific fatigue, which
may contribute to overall golf performance by improving
accuracy and drive distance, leading to a better golf score.
A second noteworthy finding in our study was the in-
crease in drive distance under the CAF condition. Longer-
drive distances result in less distance to the green, allowing
the use of a more accurate iron club on the approach shot.
Not considering environmental factors, maximum golf ball
displacement during a drive is a function of the linear ve-
locity and angle of the club head at the point of impact be-
tween the club face and ball (16). Importantly, Fletcher and
Hartwell (12) reported a strong relation between club head
speed and peak drive distance in skilled (mean handicap,
5.5) male golfers. In a laboratory-based golf-specific fatigue
study, Higdon et al. (14) reported that fatigue resulted in
a 2.0%–2.5% reduction in club head velocity when swinging
a driver, which, statistically, was not related to trunk or
pelvic rotation velocity (14). We did not observe differences
in peak trunk acceleration between conditions, but average
drive distance was significantly increased in the CAF con-
dition. It is possible that the improved drive distance was
due to the attenuation of fatigue via caffeine, which led to a
maintenance and/or increase in club head velocity. How-
ever, because we did not directly measure club head veloc-
ity, this hypothesis is only speculative, and therefore, other
factors that may have contributed to the increase in drive
distance cannot be ruled out.
There are some limitations to our investigation. First, it
is possible that some of the positive effects reported from
caffeine supplementation were due to a withdrawal effect.
Under the PLA condition, participants were asked to abstain
from consuming caffeine, which may have impaired per-
formance. Caffeine withdrawal symptoms typically appear
12 h after abstinence, and severity of symptoms is related to
the chronically consumed dose of the user (18). Further-
more, most of our participants were low-dose caffeine users
ranging between 35 and 180 mgId
j1
. Second, there are other
active secondary ingredients in the caffeine supplement that
may have contributed to our findings. Vitamin B supple-
mentation is considered beneficial when in a deficient or
malnourished state. Our subjects were apparently healthy
and did not report a history of malnourishment or hypovi-
taminosis. Furthermore, previous work reported that vitamin
B supplementation failed to show an acute effect on en-
hancing cognitive ability (23). Therefore, we do not believe
that B vitamins contributed to our findings. ElevATP
TM
is
a proprietary blend of plant bio-inorganic trace minerals
and polyphenols, which is purported to improve mitochon-
drial ATP production when consumed. To our knowledge,
only one study has been published on the acute effects of
elevATP ingestion on blood ATP concentration in humans
(24). Their results suggested that whole blood ATP levels
increased by 45% after ingestion of 150 mg of elevATP.
However, bioavailability studies of adenosine and its prod-
ucts suggest that whole blood ATP is rapidly metabolized,
on the order of minutes, by the blood components (6).
Therefore, future research should test these ingredients in-
dividually to determine their specific effects on overall golf
performance and fatigue.
Our findings suggest that skilled golfers experience
fatigue and reduced energy levels during a competitive
round of golf, which may negatively affect their playing
ability. Importantly, caffeine supplementation offset this
response, which seems to have contributed to improved iron
club accuracy, drive distance, and overall golf score. With
the lengthy duration of game play, walking long distances,
and potential environmental challenges, it is important for
competitive golfers to have evidence-based, practical rec-
ommendations to offset the physical and mental demands of
competitive golf play. Pre- and in-round nutrition and sup-
plementation strategies have thus far been lacking. For the
first time, we show that a caffeine-containing supplement,
consumed before and during a round of golf, can reduce
fatigue and improve measures of golf performance in a true
competitive tournament setting.
The funding and product support for the study were provided by
MusclePharm, Inc.
Petey W. Mumford and Aaron C. Tribby contributed equally to the
writing of the manuscript.
J. R. M. works for the funding company, whereas the remaining
authors proclaim no conflict of interest from the outcomes of this
CAFFEINE AND GOLF PERFORMANCE Medicine & Science in Sports & Exercise
d
137
APPLIED SCIENCES
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
study. J. R. M. had no influence on data collection or analysis but
contributed to the drafting and editing of the manuscript.
The results of the present study do not constitute endorsement by
the American College of Sports Medicine.
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