Bench Press and Push up Repetitions to Failure with Equated Load

Home , Bench press

BENCH PRESS AND PUSH UP REPETITIONS TO FAILURE WITH EQUATED LOAD

A Thesis

Presented to the

Faculty of

California State University, Fullerton

In Partial Fulfillment

of the Requirements for the Degree

Master of Science

Kinesiology

Taran L. Eckel

Thesis Committee Approval:

Lee E. Brown, Department of Kinesiology, Chair Andrew J. Galpin, Department of Kinesiology Jared W. Coburn, Department of Kinesiology

Spring, 2017

ABSTRACT

The bench press and push-up are used for training upper body muscular strength and endurance. Although used interchangeably, differences between relative to body mass load are unknown. The purpose of this study was to evaluate the relationship between the pushup and bench press when performing repetitions to failure with an equated load. 31 recreationally trained subjects (16 men age = 23.00 ± 2.36 years., height = 178.19 ± 9.61 cm, mass = 74.80 ± 13.44 kg; 15 women age = 23.60 ± 2.69 years, height = 160.80 ± 7.06 cm, mass = 56.32 ± 9.55 kg) performed a 1RM bench press and an isometric push-up on a force plate to determine bodyweight load supported in the pushup positions. Days 2 and 3 consisted of performing repetitions to failure for either the bench press or push-up with a load that was equal to the average relative bodyweight force of the pushup positions. A 2 (exercise: bench press, pushup) X 2 (sex: men, women) Mixed Factorial ANOVA demonstrated no interaction, but significant (p < 0.05) main effects for exercise and sex where more repetitions were performed in the pushup

(16.96 ± 9.26 reps) than the bench press (8.95 ± 4.58 reps). Also, men performed significantly more repetitions to failure in both exercises (men = 20.21 ± 9.04 reps, women = 5.70 ± 9.34 reps)). For combined sexes, there was a significant (p < 0.05), strong relationship (r = 0.83) between bench press and push-up repetitions to failure. For men, there was a significant (r < 0.05), strong relationship (r = 0.81), while for women; there was a moderate relationship (r = 0.63). The exercises should be differentiated based on the training goal and gender.

TABLE OF CONTENTS

ABSTRACT ...... ii

LIST OF TABLES ...... iv

LIST OF FIGURES ...... v

Chapter 1. INTRODCUTION ...... 1

2. REVIEW OF THE LITERATURE ...... 3

Gender Differences on Upper Body Strength ...... 3 The Push Up...... 4 The Bench Press...... 5 Repetitions to Failure ...... 5 Hand Placement of the Push Up and Grip Length of Bench Press ...... 6

3. METHODS ...... 8

Participants...... 8 Procedures ...... 8 Instruments ...... 8 Day 1: Baseline, Anthropometric Data, Force Plate Data Collection, Bench Press 1 RM Test, and Familiarization ...... 9 Day 2-3: Pushups to Failure...... 10 Day 2-3: Bench Press to Failure ...... 10 Statistical Analyses ...... 11

4. RESULTS ...... 14

5. DISCUSSION ...... 16

REFERENCES ...... 20

iii

LIST OF TABLES

Table Page

1. Main Effects of Gender and Exercise for Repetitions to Failure between the Bench Press and Pushup Exercises ...... 14

2. Correlations between Bench Press Repetitions to Failure and Push Up Repetitions to Failure by Sex ...... 15

3. Bench Press and Push Up Variables by Sex ...... 15

LIST OF FIGURES

Figure Page

1. Pushup: Up position ...... 12

2. Pushup: Down position ...... 12

3. Bench press: Top position...... 13

4. Bench press: Bottom position ...... 13

v 1

CHAPTER 1

INTRODUCTION

The bench press and push-up are commonly used for developing upper body strength and power. Although both exercises share similarities in movement parameters and benefits in the development of the upper body, the bench press usually requires expensive equipment. However, the bench press provides a training stimulus at low, moderate, and high intensities, while the load of a traditional pushup is determined by body weight (4, 5). The relationship between movements has been examined in both genders (3); however, differences may arise due to variances in upper body strength.

Even relative to bodyweight, women may be at a physiological disadvantage when performing upper body movements, such as the push up (10). Men have been shown to produce both more absolute and relative force in upper body exercises and different movement patterns in the push up (21).

Although studies have shown correlations between the two exercises there is a lack of research on gender effects in regards to the correlation between pushup performance and bench press relative to bodyweight (1). Anthropometry allows expression of intensity relative to bodyweight (14). Performing repetitions with lighter loads has shown to be a relative endurance performance attribute that indicates strength relative to bodyweight (19), while heavier loads indicate absolute strength, or the maximum capability of force production. Two popular tests of assessing muscular

2 endurance include the YMCA bench press and pushup tests; however, both tests quantify intensity relative to body weight leading to an uncertainty of the relationship between exercises (15). The purpose of this study was to evaluate to evaluate the relationship between push-ups and bench press when performing repetitions to failure with an equated load .We hypothesize that due to differences in upper body strength between genders; there will be a higher correlation between the push up and bench press in males when compared to women.

CHAPTER 2

REVIEW OF THE LITERATURE

Gender Differences on Upper Body Strength

Due to the physiological differences between men and women, upper body strength and endurance in men is greater than females. Studies have shown that women have lower force output; however contain faster recovery ability after performing high intensity exercise (24). Mier et al. investigated the effects of push-up method and gender on percentage of the supported bodyweight. The tests consisted of the performance of two sets of static push ups held for five seconds in the up and down position, which were analyzed by two AMTI force plates (21). Results showed maximal load relative to body weight was greater in men for the push up exercise (21). Eurich et al. examined the relative differences between men and women in performance of the pop-up phase of surfing. In order to simulate the pop-up phase, the recreationally trained surfers were told to lie down and place their hands down on an AMTI force plate, in which they simulated the movement by explosively lifting their body from the push-up position to the similar position of being on a surfboard (10). Results showed that men display greater relative force and greater relative power compared to women (10). Due to the physiological differences, women may not be capable of performing certain explosive movements similar to men when relative to bodyweight (10) Women may display a weakness in upper body strength that may cause a large difference in strength relative to bodyweight.

Baumgartner et al. looked to develop percentile norms for the push-up test for college students. The subjects performed a revised push up test that consisted of performing repetitions until failure, or could no longer complete a full repetition (3). Over a four year period, 177 men and 274 were tested and showed that at the 60th percentile norm, men performed 26 pushup and women performed 6 pushups (3).

The Push Up

The pushup exercise is a well-known exercise for developing upper-body strength, power, and endurance. The pushup has many variations and has shown to develop upper body musculature and intensity is based relative to the individual bodyweight. Contreras et al. examined the different biomechanical aspects of the push up. Pushups have many different variations, which lead to different muscular recruitment patterns, but the standard pushup is limited to the individual bodyweight load and anthropometry (7). The push up can be see as having many different variations, but the activation of upper-body musculature can have differences among the variations.

Gouvali, et al. recorded the dynamic behavior and musculature activation during the push-up. The subjects were told to perform the push up exercise with electrodes attached to the pectoralis major and triceps brachial muscles (12). Results showed the standard pushup has a higher EMG magnitude in the pectoralis activation than the triceps brachii during the exercise (12). An understanding of training load on the push up varies relative to the bodyweight of individual in both the up and down position (28). Suprak et al. examined the effect of position on percentage of body mass supported by the upper-body during the push up. The study found differences in the percentage of bodyweight used during the up and down position of the push up with 69% of Body Mass supported in the

5 up position and 75.04% of Body Mass supported in the down position (28). Push ups have been used to determine upper body strength however, conflicts have risen from not being able to determine a 90 degree pushup (20). In order for a push up to be reliable, the protocol of a push up test must be well-defined, simple for the subject and scorer to follow (3). As an exercise for developing upper body musculature, the regular pushup remains one of the few closed-kinetic chain exercises for developing upper body musculature and remains a standardized fitness test for upper body strength and endurance

The Bench Press

The Bench press is one of the most popular strength exercises and is used for general conditioning for athletes (1). As explained in the study by Artur et al., the bench press consists of two phases: the ascending and descending phase. The movement of the bench press matches very similar to the pushup; however, has many key differences. The most noticeable would be the ability of the bench press to have more simplicity in intensity based on absolute and relative force. Krol et al. studied the movement structure of the bench press and found differences in bar velocity and in EMG activation in the phases of bench press during absolute loads. They found that as intensity increases in the bench press, bar velocity goes down in the eccentric phases of the movement and EMG activation showed higher pectorals activation in the eccentric phase and higher triceps brachii activation in the beginning of the concentric phase (17). Peak power has also been shown to increase from 10 to 50% of 1-RM, but lowers from 50 to 90% 1-RM (27).

Repetitions to Failure

The performance of repetitions to failure is often used for the training adaptation

6 of muscular endurance and strength. The term is used to describe the point in time where a muscle fails to move a given load from a critical joint angle (8). Repetitions to failure, or until a complete repetition can longer be performed, may also be considered a repetition maximum in which a person performs the maximum number of repetitions with the given intensity (25). Sakamoto et al. investigated the effect of movement velocity on relationship between loading intensity and the total number of repetitions until failure.

Subjects were told to perform repetitions to failure using four different speeds (slow, medium, fast, ballistic) and at five intensities (40%, 50%, 60%, 70%, and 80% 1RM)

(25). Results showed an interaction between velocity and intensity in which the subjects produced more repetition at a higher velocity pace with a lower intensity (25). The speed of the exercise can affect the fatigue rate in which higher frequency of work can be accomplished at greater frequencies; however, the higher frequency causes a greater rate of fatigue (13, 26). The protocol of repetitions to failure can also affect the performance of an exercise as fatigue increases. Duffey et al. examined the effects of fatigue on the movement of a bar during the bench press exercise. Using both genders, the protocol consisted of having the subjects perform a 1 RM test followed by a repetitions to failure test using 75% of their 1RM (9). Results showed that as the subjects performed more repetitions, velocity and bar path were altered (9). As the subject reached closer to failure, the bar path resembled the bar path of the performance of performing a 1RM (9).

The performance of upper body strength training, such as the bench press exercise, with the protocol of repetitions to failure may induce higher strength gains than non-failure training (8).

Hand Placement of the Push Up and Grip Length of Bench Press

The placement of hands during an exercise can affect the musculature activation of performance, which may ultimately lead to a change the number of repetitions that can be lifted with a given intensity. The bench press and push up exercise have different hand placements that an individual will use to execute the movement. The bench press contains a moment known as the sticking point in which deceleration or no velocity occurs during the upward phase of the exercise (11). Gomo et. al sought to examine the occurrence of the sticking region by focusing on different grip lengths to see the affect of sticking point.

The subject was instructed to perform high intensity repetitions at different grip lengths

(narrow, normal, wide) in which joint angle was measured at the elbow (11). They found that the three different types of grip affected joint angle at the elbow, which lead to a change in the location of the sticking point. Grip length can affect the sticking point of the bench press, which may affect the number of repetitions a participant can produce relative to bodyweight. In contrast, EMG levels of muscular activation of the push up have been shown to be greater with a narrow hand placement position of the push up, rather than a wide-based hand placement (6, 16).

CHAPTER 3

METHODS

Participants

A total of 31 healthy, recreationally, resistance trained subjects (16 men and 15 women) who had prior experience in the bench press exercise volunteered to participate.

All subjects had no orthopedic injury or musculoskeletal injury within the past six months. Prior to the study, subjects had performed the bench press exercise for at least six months two times a week.

Procedures

Day 1: Baseline

The study consisted of three sessions separated by at least 48 hours. Upon arrival, subjects read and signed an informed consent document approved by the University IRB.

First, anthropometric measures of height was taken using an electronic scale (ES200L;

Ohaus Corporation, Pinebrook, NJ, USA) and the PRODOC Detecto stadiometer (Seca,

Ontario, CA, USA). Following NSCA procedures, fat mass was analyzed using a three- site skinfold measurement with a Skinfold Body Fat Caliper (BETA TECHNOLOGY,

Santa Cruz, CA, USA) (2, 22). For males, the three-site skinfold measurement included: the right side of the chest (a diagonal fold one-half the distance between the anterior axillary line and the nipple), abdomen (vertical fold 1 inch to the right of the umbilicus), and thigh (vertical fold on the anterior aspect of the thigh, midway between the hip and

9 knee joints) skinfold. For the females, the three-site skinfold measurement included: the right tricep (vertical fold on the posterior midline of the upper arm halfway between the acromion and the olecranon processes), suprailium (diagonal fold above the crest of the ilium at the sport where an imaginary line would come down from the anterior axillary line), and the thigh (vertical fold on the anterior aspect of the thigh, midway between the hip and knee joints). A total of two trials for each test site was measured for the skinfold measurements. The Jackson and Pollock three-site skinfold equation was used to analyze body fat percentages (22). Then the subject assumed the set up position for bench press in a squat rack (Rogue Fitness, Columbus, OH) by lying on the bench and placing their hands in a position that felt comfortable on a 20-kilogram barbell. Using a tape measure, their grip width was measured by the distance between their middle fingers. After this, they performed a warm up of three consecutive push ups. Then they rested for 2 minutes.

For isometric push up testing, subjects first stood on an AMTI force plate (Advanced

Mechanical Technology, Inc. Watertown, MA, USA) with legs shoulder-width apart and hands on their hips, for three seconds in order to measure mass. Then in random order, they performed isometric up or down positions of the pushup on the force plate for 3 seconds each. In relation to the floor, the triceps remained parallel in the up position and perpendicular in the down position. To ensure a subject was parallel to the ground in the down position a safety squat device (BFS, Salt Lake City, UT) was placed around their right tricep brachii. The subject laid down on the force plate and had their hand placement set to match the grip width measurement of their bench press. For the up position, elbows were fully extended, triceps remained perpendicular to the ground, and a straight torso from their heels to the back of their head. For the down position, triceps

10 remained parallel to the ground with a straight torso from the heels to the back of the head.

After isometric push up force was completed, subjects performed a bench press 1

RM test. Prior to the test, they warmed up with 10 repetitions at 50% of their estimated 1

RM, 5 repetitions at 70%, 3 repetitions of 80%, and 1 repetition at 90%. Each set was separated by 3 minutes’ rest. Subjects were allowed three attempts to complete their 1

RM. At the end of Day 1, subjects were given a familiarization of the next two sessions by performing push ups while wearing the safety squat device around their right tricep brachii, to insure triceps parallel at the bottom position, at a tempo of 80 beats per minute using a metronome device (EM-900; FRANZ MFG CO, INC., New Haven, CT, USA). A full repetition consisted of starting in the up position and descending to the down position and returning to the up position. After the push up repetitions were completed, they performed 5 bench press repetitions at a tempo at 60 beats per minute using the metronome device with a weight that equaled 50 percent of their 1RM. A full repetition consisted of bringing the bar down to chest level, lightly touching the sternum then returning to the up position until the elbows were fully extended and locked.

Days 2-3: Pushups to Failure (48 hours apart)

The subject started by performing a warm up consisting of 3 push ups then seated rest for 2 minutes. The safety squat device was placed around the right tricep brachii and they were instructed to perform repetitions to failure. They had their hand placement measured to match their bench press grip width. They began the test in the up position then performed repetitions with a 60 beats per minute tempo along with the metronome.

A full repetition was counted once they reached the up position. They were allowed two

11 faults in form. If a third fault was detected, the test was terminated and the two other faults were subtracted from the final number of repetitions. Faults included: not performing a full repetition, failing to complete a repetition following the tempo or could no longer perform a full repetition the body arching up causing the back to not remain parallel to the floor, slumping down that lead to the legs never coming off the floor during the up phase and a lot of straightening of the body at the waist. A repetition was counted every time the subject reached the up position on the pushup.

Days 2-3: Bench Press to Failure (48 hours apart)

Subjects started by performing a warm up consisting of 3 repetitions of the bench press exercise performed at 50% of their 1RM then seated rest for 2 minutes. The load of the bench press matched their average relative load of the isometric up and down positions of the push up exercise measured on Day 1. They laid supine on the bench and their grip width was measured to match their grip on Day 1. They performed repetitions to failure, or when they could no longer complete maintain 60 beats per minute with the metronome. A full repetition consisted of lowering the bar to the chest and raising the bar until the elbows were fully extended and locked. Faults included: failing to complete a full repetition, no longer being able to keep pace with the metronome, and not keeping the five points of contact, which included: the feet on the ground, hips on the bench, posterior deltoids on the bench, and the back of the head on the bench. A repetition was counted every time the subject-raised bar to full elbow extension

Statistical Analyses

All data were analyzed with SPSS version 24.0 software (SPSS Inc., Chicago,

IL). A2x2 (exercise x sex) mixed factor ANOVA analyzed repetitions to failure between

12 the bench press and pushup exercises. Pearson Product Moment Correlations determined relationships between variables. Independent-Samples T tests analyzed differences between body fat percentages, bench press 1-RM, bench press repetitions to failure, push up repetitions to failure, percentage of body mass used in the push-up for the up, down and average of the up and down positions, average relative bodyweight push-up force, and bench press 1 RM relative to body mass.

Figure 1. Pushup: Up position.

Figure 2. Pushup: Down position

Figure 3. Bench Press: Top position.

Figure 4. Bench Press: Bottom Position

CHAPTER 4

RESULTS

The ANOVA demonstrated no interaction but there were main effects for exercise and sex where more repetitions were performed in the pushup exercise than the bench press exercise (Table 1). Also, men performed significantly more repetitions to failure in both exercises (Table 1). For combined sexes, there was a significant, strong relationship between bench press repetitions to failure and push-up repetitions to failure (Table 2).

For men, there was a significant, strong relationship, while for women; there was a moderate relationship between bench press repetitions to failure and pushup repetitions to failure (Table 2). Men had significantly greater bench press 1RM, percentage of body mass used in the push-up down and up positions, average of the up and down positions, average relative bodyweight push-up force and bench press 1 RM relative to their body mass (Table 3).

Table 1: Main effects of sex and exercise for repetitions to failure between the bench press and pushup exercises.

Bench Press Pushup Men Women Mean 8.95 16.96* 20.21** 5.70 Standard Deviation 4.58 9.26 9.04 9.34

* Significantly greater than Bench Press ** Significantly greater than Women

Table 2: Correlations between bench press repetitions to failure and push up repetitions to failure by sex Men Women Both Pearson Correlation r = 0.81* r = 0.63* r = 0.83*

* Significant

Table 3: Bench press and push up variables by sex (mean ± SD).

Men Women Age 23.00 ± 2.36 yrs. 23.60 ± 2.69 yrs. Height 178.19 ± 9.61cm* 160.80 ± 7.06cm Mass 74.80 ± 13.44kg* 56.32 ± 9.55kg % BF 15.41 ± 5.29%* 31.87 ± 13.01% Bench Press 1 RM 99.29 ± 23.98kg* 40.91 ± 7.64kg RTF 16.38 ± 6.05reps* 1.53 ± 2.07reps 1 RM REL. BM 1.32 ± 0.22kg* 0.73 ± 0.13kg % Reps REL. PU 71.36 ± 0.17%* 18.11 ± 0.21% Push-Up RTF 24.06 ± 10.35reps* 9.87 ± 7.95reps AVG % BM UP, DWN 74.33 ± 0.03%* 70.20 ± 0.03% AVG. REL. BW 55.79 ± 11.49kg* 39.40 ± 5.74kg % BM UP 71.95 ± 0.03%* 67.08 ± 0.03% UP REL. BW 54.00 ± 11.08kg* 37.65 ± 5.54kg % BM DWN 76.70 ± 0.03%* 73.32 ± 0.03% DWN REL. BW 57.58 ± 11.97kg* 41.15 ± 6.01kg

* Significantly Different

CHAPTER 5

DISCUSSION

The purpose of this study was to evaluate the relationship between push-ups and bench press when performing repetitions to failure with an equated load. The major findings were a strong relationship between the two exercises and that more repetitions were performed in the pushup than the bench press. Also, men supported a higher percentage of their bodyweight in the pushup than women. These results may be due to differences in gender specific upper-body musculature, body fat, and trunk angle.

The bench press and pushup exercise are two well-known upper body exercises that are often used interchangeably for the development of muscular strength and endurance. Calatayud et al. observed comparable EMG amplitude levels with an equated load between the bench press and pushup exercises (5). However, in order to have an equated load; they used pushups with elastic bands, rather than the traditional pushup, and the load for each exercise was determined by a 6 RM (5). Invergo et al. concluded that pushup performance is a measure of muscular endurance load relative to body mass when compared to the maximal bench press exercise (15). Although, the current study emphasized repetitions to failure, rather than 1RM or 6 RM, an equated load was calculated relative to body mass, which may have contributed to differences in repetitions performed between the exercises.

During the performance of upper-body exercises, it has been shown that there are

17 gender differences where women produce less force relative to their body mass than men

(10, 18, 21). Constance et al. and Eurich et al. reported that men displayed greater force and power relative to bodyweight in comparison to women (10, 21). The present study found that men performed more repetitions to failure using an equated load relative to body mass, supported more of their bodyweight in both positions of the pushup, and also produced a greater positive relationship between the two exercises. Differences in pushup repetitions has also been seen in previous studies where men performed more repetitions in bodyweight exercises (3, 20). Eurich et al. concluded that women may be at a disadvantage when compared to men when producing peak performance for upper body movements which is most likely related to women’s lack of upper body muscle mass

(10).

The current study demonstrated that repetitions to failure with an equated load relative to body mass resulted in a strong positive correlation, which is similar to

Baumgartner et al. who demonstrated a high correlation between number of push-ups and bench press repetitions performed relative to their body mass (3). In comparison to the present study, Baumgartner el al. equated the load based on the up position of the pushup; however, men performed at 70% of their bodyweight, while women performed at 40%

(3). Also, their results demonstrated that men had a stronger positive correlation than females (3). McManis et al. observed that college women lacked upper-body strength to hold the down position of a pushup (20). Their subjects were asked to perform 90-degree pushups and women struggled to keep their hips off the ground (20). Similarly, in the present study women had difficulty with proper performance of pushups at 90 degrees, following tempo, and completing a full pushup repetition, possibly due to lack of upper-

18 body strength, which may have contributed to a weaker relationship between the exercises for women.

The pushup is a closed-kinetic chain exercise while the bench press is open- kinetic chain, yet they have similar biomechanical characteristics (5). Both genders displayed a strong relationship; however, gender differences were seen in total number of repetitions performed for both exercises. These differences may be due to trunk position, core activation, or usage of upper body musculature. Contreras et al. summarized the biomechanics of the pushup and concluded that maximal core muscle activation of the pushup to be primarily in the external oblique and rectus abdominis muscles (7). In contrast, Norwood et al. observed the bench press and found the highest EMG muscular core activation in the Erector spinae muscles (23). These results show that that there are differences between the pushup and bench press exercises that are commonly seen as similar. Therefore the pushup may have greater core muscular activation than the bench press, which might have led to differences in performing repetitions to failure, even with an equated load.

Differences in body position exist between the bench press and pushup. The bench press involves the participant lying down in a supine position with the head and trunk supported by the bench, knees bent, feet flat on the floor with a flat back and arms at 90 degrees to the body (17). The up position of the pushup involves the participant keeping a straight torso, but at an incline relative to the floor which becomes more parallel to the floor in the down position. Due to changes in moment arm flexion, the percentage of body mass supported is 75% body mass in the down position and 69% in the up position (7, 21). These differences may be due to whole-body center of mass being

19 directed further from the point of contact (the feet) with the support surface (the floor) leading to greater force requirements against the floor (28). Additionally, only the hands and toes touch and support the entire bodyweight (3). Therefore, the pushup resembles a decline bench press leading to a shorter moment arm, and less range of motion to complete a full repetition, which may have contributed to greater repetitions to failure than the bench press.

The findings of the current study suggest that the bench press and push-up must be considered two distinct upper body exercises both within and between genders. Use of the push-up and bench press exercises should be differentiated based on gender and goal as repetitions performed are significantly greater in the push-up even with an equated load.

REFERENCES

1. Artur G, Adam M, Przemyslaw P, Robert R, Henryk K, V G, and Courteix D. Changes of Bioelectrical Muscle Activity During Ascending Phase Flat Bench Pressing. 3rd International Congress on Physical Education, Sport and Kinetotherapy (Icpesk 2013) 117: 488-491, 2014.

2. Baechle TR, Earle RW, and National Strength & Conditioning Association (U.S.). Essentials of strength training and conditioning. Champaign, IL: Human Kinetics, 2008, p. xiv, p. 641.

3. Baumgartner TA. Objectivity, Reliability, and Validity for a Revised Push-Up Test Protocol. edited by Oh S, Chung H, and Hales DMeasurement in Physical Education and Exercise Science, 2002, p. 225-242.

4. Calatayud J, Borreani S, Colado JC, Martin F, and Rogers ME. Muscle activity levels in upper-body push exercises with different loads and stability conditions. Phys Sportsmed 42: 106-119, 2014.

5. Calatayud J, Borreani S, Colado JC, Martin F, Tella V, and Andersen LL. Bench Press and Push-Up at Comparable Levels of Muscle Activity Results In Similar Strength Gains. Journal of Strength and Conditioning Research 29: 246-253, 2015.

6. Cogley RM, Archambault TA, Fibeger JF, Koverman MM, Youdas JW, and Hollman JH. Comparison of muscle activation using various hand positions during the push-up exercise. J Strength Cond Res 19: 628-633, 2005.

7. Contreras B, Schoenfeld B, Mike J, Tiryaki-Sonmez G, Cronin J, and Vaino E. The Biomechanics of the Push-up: Implications for Resistance Training Programs. Strength and Conditioning Journal 34: 41-46, 2012.

8. Drinkwater EJ, Lawton TW, Lindsell RP, Pyne DB, Hunt PH, and McKenna MJ. Training leading to repetition failure enhances bench press strength gains in elite junior athletes. J Strength Cond Res 19: 382-388, 2005.

9. Duffey MJ, and Challis JH. Fatigue effects on bar kinematics during the bench press. Journal of Strength and Conditioning Research 21: 556-560, 2007.

10. Eurich A, Brown L, Coburn J, Noffal G, Nguyen D, Khamoui A, and Uribe B. Performance Differences Between Sexes in the Pop-Up Phase of Surfing. Journal of Strength and Conditioning Research 24: 2821-2825, 2010.

11. Gomo O, and van den Tillaar R. The effects of grip width on sticking region in bench press. Journal of Sports Sciences 34: 232-238, 2016.

12. Gouvali M, and Boudolos K. Dynamic and electromyographical analysis in variants of push-up exercise. Journal of Strength and Conditioning Research 19: 146- 151, 2005.

13. Headley S, Henry K, Nindl B, Thompson B, Kraemer W, and Jones M. Effects of Lifting Tempo on One Repetition Maximum and Hormonal Responses to a Bench Press Protocol. Journal of Strength and Conditioning Research 25: 406-413, 2011.

14. Hetzler R, Schroeder B, Wages J, Stickley C, and Kimura I. Anthropometry Increases 1 Repetition Maximum Predictive Ability of NFL-225 Test for Division IA College Football Players. Journal of Strength and Conditioning Research 24: 1429-1439, 2010.

15. Invergo JJ. Relationship of Push-Ups and Absolute Muscular Endurance to Bench Press Strength. edited by Ball TE, and Looney MJournal of Applied Sport Science Research, 1991, p. 121-125.

16. Kim YS, Kim DY, and Ha MS. Effect of the push-up exercise at different palmar width on muscle activities. J Phys Ther Sci 28: 446-449, 2016.

17. Krol H, Golas A, and Sobota G. Complex analysis of movement in evaluation of flat bench press performance. Acta of Bioengineering and Biomechanics 12: 93-98, 2010.

18. Linnamo V, Pakarinen A, Komi PV, Kraemer WJ, and Häkkinen K. Acute hormonal responses to submaximal and maximal heavy resistance and explosive exercises in men and women. J Strength Cond Res 19: 566-571, 2005.

19. Mayhew JL. Relative Muscular Endurance Performance as a Predictor of Bench Press Strength in College Men and Women. edited by Ball TE, Arnold MD, and Bowen JCJournal of Applied Sports Science Research, 1992, p. 200-206.

20. McManis BG. Objectivity and Reliability of the 90° Push-Up Test. edited by Baumgartner TA, and Wuest DAMeasurement in Physical Education and Exercise Science, 2000, p. 57-67.

21. Mier C. Differences between Men and Women in Percentage of Body

Weight Supported during Push-up Exercise. edited by Amasay T, Capehart S, and Garner HInternational Journal of Exercise Science, 2014, p. 161-168.

22. Moon JR, Tobkin SE, Smith AE, Lockwood CM, Walter AA, Cramer JT, Beck TW, and Stout JR. Anthropometric estimations of percent body fat in NCAA Division I female athletes: a 4-compartment model validation. J Strength Cond Res 23: 1068-1076, 2009.

23. Norwood JT, Anderson GS, Gaetz MB, and Twist PW. Electromyographic activity of the trunk stabilizers during stable and unstable bench press. J Strength Cond Res 21: 343-347, 2007.

24. Ratamess NA, Chiarello CM, Sacco AJ, Hoffman JR, Faigenbaum AD, Ross RE, and Kang J. The effects of rest interval length on acute bench press performance: the influence of gender and muscle strength. J Strength Cond Res 26: 1817-1826, 2012.

25. Sakamoto A, and Sinclair PJ. Effect of movement velocity on the relationship between training load and the number of repetitions of bench press. Journal of Strength and Conditioning Research 20: 523-527, 2006.

26. Sakamoto A, and Sinclair PJ. Muscle activations under varying lifting speeds and intensities during bench press. Eur J Appl Physiol 112: 1015-1025, 2012.

27. Stock MS, Beck TW, Defreitas JM, and Dillon MA. Relationships among peak power output, peak bar velocity, and mechanomyographic amplitude during the free- weight bench press exercise. J Sports Sci 28: 1309-1317, 2010.

28. Suprak DN, Dawes J, and Stephenson MD. The effect of position on the percentage of body mass supported during traditional and modified push-up variants. J Strength Cond Res 25: 497-503, 2011.