Subjects
20 healthy amateur players from German golf clubs were asked to participate in this study. Two groups with 10 golfers each and different skill levels (handicap) were recruited for the study. We formed one group with handicap (Hcp) below 11.5 (LOW) and one group with handicap between 18.5 and 26.4 (HIGH). Baseline data and subjects characteristics are shown in table 1. All subjects were enlightened about benefits and risks regarding all study procedures. The study was approved by the local ethics committee of the Medical School Hannover and all subjects gave their informed written consent beforehand of any procedures. No subjects under age of 18 years were included in the study.
Table 1: Anthropometric data of included subjects at baseline.
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All subjects
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Group Hcp low
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Group Hcp high
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p-value
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Subjects (n)
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20
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10
|
10
|
|
Age (years)
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33.0 ± 9.4
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25.9 ± 5.8
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40.1 ± 6.3
|
<0.001
|
Handicap
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12.7 ± 10.3
|
2.9 ± 2.7
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22.5 ± 2.4
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<0.001
|
Golf experience (years)
|
12.7 ± 5.8
|
12.1 ± 5.2
|
4.9 ± 3.8
|
0.002
|
Weight (kg)
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82.9 ± 7.7
|
80.1 ± 6.9
|
85.8 ± 7.7
|
0.098
|
Height (cm)
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183.4 ± 6.7
|
182.6 ± 6.0
|
184.2 ± 7.6
|
0.596
|
Body mass index
|
24.7 ± 2.2
|
24.1 ± 2.3
|
25.3 ± 1.9
|
0.211
|
Exercise Testing
The participants performed a graded exercise test (GXT), a driving range training program and played 9 holes of golf under the official rules of golf conducted by the Royal and Ancient Golf Club of St. Andrews. The testing sessions were held on three different days for each subject.
The GXT was carried out on a stationary bicycle ergometer (Ergoline 150P, Bitz, Germany) to test for VO2peak and maximum power (Pmax). VO2peak was documented as the highest mean of one minute oxygen uptake. The GXT started at 50W with a 16.66 W increase every minute. Gas exchange (breath-by-breath, MasterScreen CPx Carefusion, Höchberg, Germany) and an electrocardiogram were assessed continuously. Blood pressure and blood lactate concentration (lac) were assessed every 3 minutes during the GXT. Capillary blood samples for lac measurements were drawn from a hyperaemized ear lobe and immediately analyzed using a Biosen C-line (EKF Diagnostics GmbH, Barleben).
Golf Exercise/ Playing Session
The driving range program included 5 shots with each of a total of five predefined golf clubs. All subjects used the same order of clubs. Just as the common routine in golf training the order started from irons (9, 7 and 5) to long clubs (3 wood and driver). Each stroke of one club was made within 30 seconds. The pause in between clubs was 2 min. All subjects used their own clubs.
For the round of 9 holes (Front nine, Golf Club Hannover e. V., Garbsen, Germany) the participants played under the terms of competition in the Stableford format. The slope of the golf course is 142 and its course rating is 73.4 with par 72 calculated for playing the front nine twice. The topography of the golf course is rather flat with the lowest point at 43 m above sea level and highest point at 54m above sea level, walking 28m up- and downwards and a distance of 4.2 km on the front nine in total. Participants walked the course and used a 3-wheel push trolley for their golf bags. All subjects were allowed to use a laser rangefinder to measure distances. Except for scoring no caddies or help from other persons was allowed during the golf round.
Gas exchange data and heartrate was continuously captured during the golf exercise session and the 9-hole competition round using an Oxicon mobile device (breath-by-breath, Carefusion, Höchberg, Germany) and a Polar T31 chest strap (Polar Electro, Kempele, Finland). After the measurement we calculated means of %VO2, %HR and METs for the 9 holes of competitive golf and the exercise on the driving range. The results were put into relation to the categories for estimating intensity of cardiovascular exercise as seen in table 2 which were adapted according to the guidelines from the American College of Sports Medicine (ACSM)(3).
Table 2: HRmax, maximum heartrate; VO2peak, peak oxygen consumption; MET, metabolic equivalent of task; adapted from(3).
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Relative Intensity
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Absolute Intensity (MET) by Age
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Intensity
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%HRmax
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%VO2peak
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Young (20 - 39 yrs)
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Middle Age (40 - 46 yrs)
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Very Light
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<57
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<37
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<2.4
|
<2.0
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Light
|
57 - 64
|
37 - 45
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<4.8
|
<4.0
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Moderate
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64 - 76
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46 - 64
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4.8 - 7.2
|
4.0 - 6.0
|
Vigorous
|
76 - 96
|
64 - 91
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7.2 - 10.2
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6.0 - 8.5
|
Statistics
Figures and tables contain mean values with standard deviation. All figures containing spirometrical data display 30s mean values. Statistical significance was set to p<0.05. Statistical significance was tested with a two sided student’s T-test for independent samples.