Muscle activation during the chin-up exercise versus the lat-pulldown exercise using different workloads : An Electromyography study

Background: Two commonly used strength training exercises are the chin-up- and the lat-pulldown exercise. Both exercises are performed by using similar movement patterns and by using the same primary muscles. Previous research has shown that each exercise can exhibit unique training stimulus and should not be considered interchangeably. However, there is limited research regarding comparison of muscle activation between the exercises. Knowing the amount of muscle activation when performing the exercises, can help strength training participants to choose exercise and relative workload according to the specific muscles they want to target. Purpose: This study sought to compare muscle activation (measured as average) in m. latissimus dorsi (LD), m. biceps brachii (BB), middle m. trapezius (TR) and m. rectus abdominis (RA) between performing the chin-up at 100% of participants’ individual bodyweight (BW) with lat-pulldown at 50%-, 65%- and 75% BW. Methods: Twenty strength trained male participants (25.0 ± 3.3 yr; 181.0 ± 5.8 cm; 82.0 ± 7.8 kg) were examined during the study. Surface electromyography (SEMG) was collected from LD, BB, TR & RA during the exercises. Average muscle activation was expressed as percentage of maximum voluntary isometric contraction (%MVIC). Exercise execution was as identical as possible for both exercises and was performed using pronated handgrip and a grip width equal to 1.5 times the participants individual biacromial distance. Results: Statistically significant (p<0.05) increases in average muscle activation were found in LD, BB and RA during chin-up 100% BW compared to lat-pulldown at 50%-, 65% and 75% BW. However, for TR no significant difference (p=0.145) was found between chin-up 100% BW and lat-pulldown when performed at 75% BW. Conclusion: These results indicate that performing the lat-pulldown using workload somewhere between 75-100% BW can exhibit the same muscle activation as performing the chin-up at 100% BW. Keywords: Strength training, Surface electromyography, Muscle activation, Chin-up exercise, Latpulldown exercise, Different workloads, Randomisation, Cross-over, Observationa