Effects of Unilateral, Bilateral and Combined Resistance Training on the Speed and Accuracy of the Serve in Youth Tennis Players
Phase: NA
Conditions: Exercise Training
Sponsor: Universiti Putra Malaysia

Effects of unilateral, bilateral and combined resistance
training on the speed and accuracy of the serve in youth
tennis players
Expert Information
Work Unit:
University of Putra Malaysia
Full name:
Ma Xudong
Title:
Effects of unilateral, bilateral and combined resistance
training on the speed and accuracy of the serve in youth
tennis players
Research Area:
Physical Education
Working Experience:
School assistant, coach
15/ 5/ 2024

Dear Professor,
My name is Ma Xudong, and I am a PhD student majoring in Physical
education at Universiti Putra Malaysia (UPM). The aim of this study was to
investigate the effects of single, bilateral and combined resistance training
on the speed and accuracy of serving in Chinese amateur teenage tennis
players.The subjects were young male tennis players aged 16-20 years from
four universities in Gansu Province. The data obtained in this survey were
used for academic research only. Therefore, I invited experts to evaluate and
score the experimental design to help me better complete this experiment.
Thank you very much.
The study was divided into control group (CG), experiment group 1
(EG1-unilateral group), experiment group 2 (EG2-bilateral group) and
experiment group 3 (EG3-combined group). Used to compare the effects of
different forms of resistance training on serve speed and accuracy. Previous
studies have shown that unilateral and bilateral resistance training can
effectively improve athletes' strength, explosive power, and speed (Speirs, et
al., 2016; Davo, Jimenez, & Solana,., 2018), there is still controversy when
comparing the advantages and disadvantages of two forms of resistance
training (Ramirez-Campillo et al., 2015; Donathb & Wahl., 2022). In this
study, unilateral resistance training, bilateral resistance training, and
combined
unilateral
and
bilateral
resistance
training
were
used
as
intervention modalities.
Based on the literature review, the training frequency of this experiment was
arranged as 2 sessions/week, and the total training time was 6 weeks, with a
fixed duration of each training session. Each training session lasted a
maximum of 60 minutes. In this experiment, the interval between two

weekly training sessions was at least 24 h to prevent subjects from being in
a fatigued state in the relevant muscle groups of the body and affecting the
experimental level.
1. Pre-activation Prescription
week
Intensity
of
Pre-activation
Type of
Warm-up
Type of Exercise
Intensity &
Repetition
Sets
Recovery
Time
1-6
CG
Routine
Warm-up
Routine Warm-up
NO
NO
NO
EG1
Dynamic
Warm-up
Dynamic warm
up
(Table1)
NO
1
1min
EG2
Dynamic
Warm-up
Dynamic
Warm-up
(Table1)
NO
EG3
Dynamic
Warm-up
Dynamic
Warm-up
(Table1)
NO

Table1
EG1
EG2
EG3
Dynamic Warm-Up
(Time)
1. High-knee walk. While walking, lift knee towards chest, raise body on toes, and swing alternating
arms.
2. Straight-leg march. While walking with both arms extended in front of body, lift one extended leg
towards hands then return to starting position before repeating with other leg.
3. Hand walk. With hands and feet on the ground and limbs extended, walk feet towards hands while
keeping legs extended then walk hands forward while keeping limbs extended.
4. Lunge walks. Lunge forward with alternating legs while keeping torso vertical.
5. Backward lunge. Move backwards by reaching each leg as far back as possible.
6. High-knee skip. While skipping, emphasize height, highknee lift, and arm action.
7. Lateral shufflfle. Move laterally quickly without crossing feet.
8. Back pedal. While keeping feet under hips, take small steps to move backwards rapidly.
9. Heel-ups. Rapidly kick heels towards buttocks while moving forward.
10. High-knee run. Emphasize knee lift and arm swing while moving forward quickly.
This study recommends a warm-up with dynamic exercises and a cool-down using body stretching. Warm-up programmes have
been shown to be effective in improving jumping performance and are recommended for young people as a standardised
warm-up prior to RT (Faigenbaum et al., 2005).

Expert score: your evaluation of measurements is (the full score is 10
points, 9-10 points are very applicable, 7.5-8.5 points are applicable, 6-7
points are less applicable, and 4.5-5.5 points are not applicable.)
Order
Items
Score
1
The Content of whole Training Program
2
Intensity of Pre-activation
3
Type of Warm-up
4
Type of Exercise
5
Intensity & Repetition
6
Training Sets
6
Recovery Time
Modification Suggestions of Experts:

2. Basic Training Program
EG1
EG2
EG3
CG
Dynamic Warm-Up and Training (Time)
Routine Warm-Up and Training
(Time)

High-knee walk- 1 time ( 1min )

Straight-leg march -1 times (1min)

Hand walk - 1sets- 1 time ( 1min )

Lunge walks - 1 time ( 1min )

Backward lunge - 1 time ( 1min )

High-knee skip -1 time ( 1min )

Lateral shufflfle- 1 time ( 1min )

Back pedal -1 time ( 1min )

Heel-ups -1 time ( 1min )

High-knee run -1 time ( 1min )

Unilateral, bilateral, combined resistance training ( EG1, EG2,
EG3) (50 min)

Total time (60min)

Jogging - 1 time (10 min)

traditional training（50min）

Total time (60min)
Training Content
(Training base phase (first two weeks): 65-75% of intensity, 2sets, 8raps)（NSCA，2009）

Specific Intervention Prescription
Unilateral resistance training programme
Unilateral training（1h）
Category
Free weight resistance training
movements
（NSCA，2009）
Intervals
Rapid Contraction resistance
Training
（Carter，2014）
Upper
limb
Unilateral Bench Press
Dumbbell
dominant limb: 50% 1RM, 4 × 8;
Non-dominant limb: 50% 1RM, 4 × 8
VIPR energy barrel for
unilateral bench press
dominant limb: 50% 1RM, 4 × 8;
Non-dominant limb: 50% 1RM, 4 × 8
2min
One-handed push-ups on
box
(dominant limb: 4 x 10;
non-dominant limb: 4 x 10)
medicine ball forward throw
(dominant limb: 4 x 10;
non-dominant limb: 4 x 10.)
Stretch band continuous
tennis swing action
(dominant limb: 4 x 20;
non-dominant limb:4 x 20.)
lower limb
Bulgarian Arrow Squat
dominant limb:50% 1RM, 4×8
Non-dominant limb :50% 1RM, 4×8
Bulgarian unilateral heel lift
dominant limb :50% 1RM, 4 x 8
Non-dominant limb:50% 1RM, 4 x 8
2min
Self-weighted cross lunge
jump
(dominant limb: 4 x 10;
non-dominant limb: 4 x 10)
Single foot hurdle vertical
jump
0.25cm (dominant limb: 4 x10;
non-dominant limb: 4 x10)
(Training base phase (first two weeks): 65-75% of intensity, 2sets, 8raps)（NSCA，2009）

Bilateral resistance training programme
Bilateral training（1h）
Category
Free weight resistance training
movements
（NSCA，2009）
Intervals
Rapid Contraction resistance
Training
（Carter，2014）
Upper
limb
Bench Press for
Dumbbell
(80-85%1RM 4×8）
VIPR energy barrel for
bench press
(80-85%1RM 4×8）
2min
High five with push-ups
(4×10)
Double-sided medicine ball
forward throw
(4×10)
Stretch band continuous
tennis swing action
（Bilateral ）
(4×20)
lower limb
Bilateral Weight Squat
(80-85%1RM 4×8）
Bulgarian
Heel Lift
(80-85%1RM 4×8）
2min
Jump box
(3×10)
Hurdle Vertical Jump
0.25cm，4×10
(Training base phase (first two weeks): 65-75% of intensity, 2sets, 8raps)（NSCA，2009）

Combined（UL+BL）resistance training programme
Combined（UL+BL）ltraining（1h）
Category
Free weight resistance training
movements
（NSCA，2009）
Intervals
Rapid Contraction resistance
Training
（Carter，2014）
Upper
limb
Unilateral Bench Press
Dumbbell
dominant limb: 50% 1RM, 4 × 8;
Non-dominant limb: 50% 1RM, 4 × 8
VIPR energy barrel for
bench press
(80-85%1RM 4×8）
2min
One-handed push-ups on
box
(dominant limb: 4 x 10;
non-dominant limb: 4 x 10)
Double-sided medicine ball
forward throw
(4×10)
Stretch band continuous
tennis swing action（Bilateral
and Unilateral）
(2×20/2×20)
lower limb
Bulgarian Arrow Squat
dominant limb:50% 1RM, 4×8
Non-dominant limb :50% 1RM,4×8
Bulgarian
Heel Lift
(80-85%1RM 4×8）
2min
Self-weighted cross lunge
jump
(dominant limb: 4x 10;
non-dominant limb: 4 x 10)
Hurdle Vertical Jump
0.25cm，4×10
(Training base phase (first two weeks): 65-75% of intensity, 2sets, 8raps)（NSCA，2009）

Expert score: your evaluation of training program is (the full score is 10
points, 9-10 points are very applicable, 7.5-8.5 points are applicable, 6-7
points are less applicable, and 4.5-5.5 points are not applicable.)
Order
Items
Score
1
The Content of whole Training Program
2
Warm-up
3
Training Duration & Frequency
4
Type of Exercise
5
Training Intensity & Repetition
6
Training Sets
7
Recovery Time
Modification Suggestions of Experts:

3.Instruments
Sport performance tests（The contribution of the tennis serve）
TEST
5RM-BS
5RM-BP
CMJ
OMB
SJF
SRT
HEC
PURPOSE
Maximum strength of the upper limb
Maximum strength of the lower
limb
Maximum
power of the
lower limb
Maximum power
of the upper limb
Flexibility of upper
limb joints
Flexibility of
lower limb
joints
body coordination
EQUI
PAM
ENT
Barbell（kg）
Barbell（kg）
APP （cm）
Measuring tape
（m）
Ruler with scale
(cm)
Ruler with
scale (cm)
Stop watch（times）
POSITION
Subjects were supine on a bench,
which was parallel to the floor. The
back of the subject should be close to
the surface of the table, with the knees
in the same direction as the toes
Subjects were instructed to
stand behind the barbell with
their feet shoulder-width apart
and their knees facing in the
same direction as their toes
The subject
remains standing
The subject
remains standing
Subjects remain
standing
The subject
remained in a
seated
position
The subject stood
with a tennis ball in
hand
ACTION
The subject held the dumbbell tightly.
Subjects had to reach the specified
depth with downward motion (90° at
the elbow). In addition, the direction of
the dumbbell should be consistent with
the direction of the nipple throughout
the movement
Move your toes outward 30°.
The barbell was clenched and
the hands rested on the scapula.
The subject must reach the
specified depth ((90° knee
Angle)) when moving down.
The subjects
kept their hands
still and
completed the
jump during the
squat
Subjects grabbed
the medicine ball
and threw it as
far as they could
over their heads
The upper limbs of
the subjects were
extended and
rotated backward
without tilting the
trunk
Subjects had
their legs
straight and
their upper
limbs
extended
forward
The subject threw
the tennis ball
against the wall
and repeated the
action until the ball
fell to the ground
MEASUR
EMENT
The maximum weight that can be
pushed
The maximum weight that can
be pushed
The vertical
height of the
jump
Horizontal
distance
The distance
between the hands
Horizontal
distance
Number of times in
30 seconds

Tennis serve performance
TEST
SPEED TEST
ACCURACY TEST
PURPOSE
Measure the speed of a tennis serve
To measure the accuracy of a tennis
serve
EQUIPAMENT
radar gun（Bushnell-10-1911）
Figure 1（score）
POSITION
The subject was prepared to complete the
serve movement
The subject was prepared to
complete the serve movement
ACTION
The subject completed the serve
movement
The subject completed the serve
movement
MEASUREMENT
Km/h
Score
Figure 1-Tennis accuracy Tes

Expert score: your evaluation of measurements is (the full score is 10
points, 9-10 points are very applicable, 7.5-8.5 points are applicable, 6-7
points are less applicable, and 4.5-5.5 points are not applicable.)
Order
Items
Score
1
5RM -Bench press
2
5RM -Back squat
3
Counter movement Jump
4
Overhead medicine ball
5
Shoulder Joint Flexibility Test
6
Sit and reach Test
7
Hand-Eye Coordination Test
8
Tennis speed Test
9
Tennis accuracy Test
Modification Suggestions of Experts:

Dynamic warm-up content
(Athlete in Photo: One of the participants)
1. High-knee walk
While walking, lift knee towards chest, raise body on toes, and swing alternating arms.
2. Straight-leg march
Straight-leg march. While walking with both arms extended in front of body, lift one
extended leg towards hands then return to starting position before repeating with other
leg.

3. Hand walk
With hands and feet on the ground and limbs extended, walk feet towards hands while
keeping legs extended then walk hands forward while keeping limbs extended.
4. Lunge walks.
Lunge walks. Lunge forward with alternating legs while keeping torso vertical.

5. Backward lunge.
Move backwards by reaching each leg as far back as possible.
6. High-knee skip.
While skipping, emphasize height, highknee lift, and arm action.

7. Lateral shufflfle.
Move laterally quickly without crossing feet.
8. Back pedal.
While keeping feet under hips, take small steps to move backwards rapidly.
9. Heel-ups.

Rapidly kick heels towards buttocks while moving forward.
10. High-knee run.
Emphasize knee lift and arm swing while moving forward quickly.

Training content
(Athlete in Photo: One of the participants)
Unilateral resistance training content
Unilateral Bench Press Dumbbell

VIPR energy barrel for unilateral bench press
Bulgarian Arrow Squat

Bulgarian Heel Lift
One-handed push-ups on box

medicine ball forward throw
Self-weighted cross lunge jump

Single foot hurdle vertical jump

Unilateral resistance training content
Bench Press for Dumbbell

VIPR energy barrel for bench press

Bilateral Weight Squat
Bulgarian Heel Lift

High five with push-ups
Double-sided medicine ball forward throw

Jump box
Hurdle Vertical Jump

Statistical Analysis Plan
Grouping
of subjects
Interven
tion
Pre
Post-1
Post-2
∆
Statistical Analysis
T-test/ANOVA
ANOVA
Within group
between groups
Subject-1
XU
XUO1
XUO2
XUO3
Post1-pre
(O∆1)
Post2-pre
(O∆2)
Post2-Post1(O∆3)
Post1 VS pre
(T-test)
Post2 VS pre
(T-test)
Post2 VS Post1 (T-test)
O∆1 VS O∆2 VS O∆3（ANOVA）
Post-1：
O∆1 VS O∆4 VS O∆7 VS O∆10（ANOVA）
Post-2：
O∆2 VS O∆5 VS O∆8 VS O∆11（ANOVA）
Subject-2
XB
XBO4
XBO5
XBO6
Post1-pre
(O∆4)
Post2-pre
(O∆5）
Post2-Post1(O∆6）
Post1 VS pre
(T-test)
Post2 VS pre
(T-test)
Post2 VS Post1 (T-test)
O∆4 VS O∆5 VS O∆6（ANOVA）
Subject-3
XC
XCO7
XCO8
XCO9
Post1-pre
(O∆7)
Post2-pre
(O∆8)
Post2-Post1(O∆9)
Post1 VS pre
(T-test)
Post2 VS pre
(T-test)
Post2 VS Post1 (T-test)
O∆7 VS O∆8 VS O∆9（ANOVA）
CG
X
XO10
XO11
XO12
Post1-pre
(O∆10)
Post2-pre
(O∆11)
Post2-Post1(O∆12)
Post1 VS pre
(T-test)
Post2 VS pre
(T-test)
Post2 VS Post1 (T-test)
O∆10 VS O∆11 VS O∆12（ANOVA）
Dependent variables: strength, explosive power, flexibility, coordination, serve speed, accuracy

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