Bench press and push-ups are two ubiquitous resistance exercises with a primary objective to strengthen the upper body. In addition, these two exercises are often used to assess upper body muscular strength and endurance. The bench press is an open kinetic chain movement while pushups are a closed kinetic chain movement that are deemed biomechanically comparable to each other (both involve shoulder horizontal flexion and extension and elbow flexion and extension) (Blackard et al., 1999; Dillman et al., 1994; van den Tillaar and Saeterbakken, 2014). However, when the bench press load is matched to the push-up load, the number of repetitions performed to failure is much higher for the push-up exercise versus the bench press. Amasay et al. (2016) recently reported a greater number of push-ups (33 vs. 30 push-ups) performed than bench press (25 vs. 6 repetitions) when the load was matched to the body mass during a push-up for both men and women, respectively. However, in their study, women performed modified push-ups (fulcrum point at the knees rather than the toes) and there was no measure of neuromuscular activation to help identify the different mechanisms regarding the exercises and sex factors. Clemons et al. (2019) also examined push-up performance but only with young men (n=31; 20.2+2.1 years), using multiple regression analysis to determine bench press one repetition maximum (1RM) from the maximum push-ups repetitions. Since push-ups are relatively safe and stable with little coordination needed to perform them and do not need specialized equipment, they should be an ideal exercise for which to predict upper body training loads such as with the bench press. Since the bench press barbell has greater instability creating a need for greater coordination, predicting bench press training requirements for each sex from this simple exercise would be very advantageous to both the fitness professional and enthusiast.
There must be other contrasts between the exercises such as differences in neuromuscular activation that contribute to the disparity in repetitions. Calatayud et al. (2015) reported that the push-ups and bench press can be used interchangeably for strength gains in terms of neuro-muscular activation. Similarly, pectoralis major, anterior deltoid, biceps brachii, and triceps brachii electromyo-graphic (EMG) activity were similar between bench press and push-up variations (Gottschall et al., 2018). In contrast, Danielsson (2017) showed higher pectoralis major muscle activation when averaging five repetitions of the bench press (64% of body mass), versus five push-ups at a rate of 40 bpm. Comparably, a systematic review concluded that with the bench press, the EMG activity of the pectoralis major and triceps brachii were similar but both muscles were higher compared to the activity of the anterior deltoid due to their muscular size and force production ability (Stastny et al., 2017).
Perhaps there are a greater variety of EMG differences between push-up and bench press muscle activation (i.e. EMG amplitude, median frequency, timing pattern) than just overall EMG activity. For example, pectoralis major, anterior deltoid and triceps brachii EMG activity increased during the ascending phase (concentric) of a bench press, while the EMG activity of the pectoralis major and anterior deltoid increased during the descending (eccentric) phase with a 6-repetition maximum (van den Tillaar and Saeterbakken, 2014). One underlying principle of fatigue is its task dependency (Enoka and Stuart, 1992). With fatigue, pectoralis major, triceps brachii, and anterior deltoid activation increased while maintaining movement pace during a bench press (Sakamoto and Sinclair, 2012). Brennecke et al. (2009) found when an induced fatigue protocol was introduced, only the pectoralis major increased muscular activity during the tonic (stabilizing) phase of bench press. However, there are no studies that have examined changes in associated muscle activity with push-ups to fatigue. The limited number of repetitions (1-6 repetitions) used in prior research (Calatayud et al., 2015; Gottschall et al., 2018) may not have accentuated any possible differences between push-ups and bench press. The greater stresses associated with fatigue may better delineate neuromuscular activation and task differences (i.e. trunk stabilization with push-ups, barbell instability with bench press, excursion of the bench press barbell versus body mass with push-ups) between push-ups and bench press.
When performing push-ups, women experienced near significantly higher pectoralis major (p = 0.06) and triceps brachii (p = 0.17) EMG activity and higher triceps brachii EMG variability than men (Cogley et al., 2005). In bench press, females demonstrated higher pectoralis major, anterior deltoid muscle activity compared to men while performing 55%, 70%, 85%, and 100% of one maximum repetition. However, unlike push-ups, men demonstrated a higher triceps activity compared to women in the bench press (Golas et al., 2018). With the scant research examining sex differences in these two ubiquitous resistance exercises, more studies are necessary.
Thus, the objective of this study was to examine differences in the number of repetitions performed and EMG activity of associated muscles (pectoralis major, anterior and medial deltoid, triceps brachii and biceps brachii) between load matched bench press and push-ups in young adult men and women. A second objective was to provide regression equations to predict the appropriate number of bench press repetitions from testing of push-up repetitions. It was hypothesized that a greater number of repetitions would be executed with push-ups while higher muscle activation would be observed during the load matched bench press. Secondly, based on the greater upper body muscle mass and strength of men, it was hypothesized that men would exceed women with both push-up and load matched bench press repetitions.
This was a quasi-experimental design study. Ten men and 10 women performed maximum push-up and bench press repetitions with loads relative to the push-up resistance. Electromyographic (EMG) electrodes were positioned on the middle and anterior deltoids, triceps and biceps brachii, and pectoralis major muscles and their relative (normalized to an isometric bench press maximum voluntary contraction) activity was compared between the two exercises performed to task failure (maximum number of repetitions). Correlation coefficients and equations were derived to predict the number of bench press repetitions performed from maximum push-up repetitions.
Based on changes in maximum repetition numbers as well as EMG measures from anterior deltoid, pectoralis major, biceps brachii, and triceps brachii from previous studies (Amasay et al., 2016; Gottschall et al., 2018), a priori statistical power analysis was conducted. It was determined that a sample size of 3-6 (calculation predictions based on number of repetitions) and 6-26 (calculation predictions from the four monitored muscles) were needed to achieve an alpha of 0.05 and a power of 0.8. The average sample size number from the EMG measures was then calculated (n = 14); hence, 20 participants (males = 10: 22 [+ or -] 6.1 years, 1.78 [+ or -] 0.34 m, 81.4 [+ or -] 9.8 kg; female s= 10: 24 [+ or -] 5.7 years, 1.60 [+ or -] 0.59 m, 62.5 [+ or -] 7.7 kg;) were recruited through convenience sampling. Participant inclusion criteria included healthy individuals, 18-30 years with resistance training experience (averaged [greater than or equal to]2 resistance training sessions per week over the prior 6 months). Exclusion criteria included participants with upper body musculoskeletal injuries within the prior 6 months. Participants were informed that no stimulants (i.e. caffeine, nicotine or others) were to be ingested at least 6 hours prior to testing. Fluid intake was permitted ad libitum. After familiarizing the participants with the general scope of the study, they read and signed a consent form. The study was approved from the local ethical committee (ID:HKR20200042).
Push-up test (calculation of the load for the bench press)
Two Taylor[R] (model: 7410BL, Taylor Precision Products, Inc., Las Cruces, NM, USA) scales were placed at shoulder width (thumbs directly under the acromioclavicular joint) for the push-up position. The digital scales were calibrated with weights to a load cell (S-beam load cell, model number LC101-500, Omegadyne, Inc., Sunbury, OH, USA). Based on this shoulder width and the same...