Struggling with the pull up? What does the research say?

Determinant factors of pull up performance in trained athletes, by Sánchez-Moreno, Pareja-Blanco, Díaz- Cueli, & González-Badillo, in The Journal of Sports Medicine and Physical Fitness (2015)

Background

Although lat-pull downs, pull-ups and chin-ups are common exercises that appear in most resistance training programs for both athletes and bodybuilders for developing the latissimus dorsi and other middle back muscles, they have not been widely studied by researchers. What research has been performed has largely investigated the hand-position, grip width and head position of either pull-ups or lat pull-downs. Grip width (wide vs. narrow), hand position (pronated vs. supinated) and head position (behind the head vs. in front of the head) all appear to affect the muscle activity of some of the back and arm muscles during both pull-ups and lat pull-downs. In terms of the latissimus dorsi, it has been found that latissimus dorsi muscle activity is greater in wide grip lat pull- downs than in narrow grip pull-downs, even though the load that can be lifted is lower in wide grip lat pull- downs than in narrow grip lat pull-downs. However, it seems that latissimus dorsi muscle activity is similar between behind the head and in front of the head positions. Also, using a pronated grip leads to greater latissimus dorsi muscle activity than a supinated grip, although the reverse is the case for biceps brachii muscle activity. In addition, although they appear very similar exercises, there are some differences in muscle activity between the lat-pulldown and the pull-up or chin-up exercises. Although the two exercises display similar latissimus dorsi muscle activity, the biceps brachii and erector spinae muscles seem to involve greater muscle activity during chin-ups than during the lat pull-down. The reasons for these differences are unclear but may relate to the relative stability of the two exercises.

OBJECTIVE: To evaluate the relationships between pull up and lat pull-down performances at various loads, by reference to the maximum number of pull ups, the 1RM lat pull-down, the maximum number of lat pull-down repetitions with 80% of 1RM, the maximum number of lat pull-down repetitions with body mass, and to explore whether pull up or lat pull- down performances are explained by any individual anthropometric variables (body height, body mass, body composition as estimated by skinfold analysis).

POPULATION: 25 trained males (either firefighters or policeman candidates), aged 26.8 ± 6.3 years.

INTERVENTION: All subjects performed both pull up and lat pull-down tests, including maximum number of pull ups (rep-BW-PU), the 1RM lat pull-down (1RM- LP), the maximum number of lat pull-down repetitions with 80% of 1RM (rep-80%-LP), and the maximum number of lat pull-down repetitions with body mass (rep-BW-LP).

What happened?

Relationship between pull ups and lat pull-downs

The researchers reported the presence of significant relationships between rep-BW-PU and rep-BW-LP (r = 0.62) and between rep-BW-PU and 1RM-LP relative to bodyweight (r = 0.59) but not between rep-BW-PU and rep-80%-LP (r = 0.14) or between rep-BW-PU and 1RM-LP (r = 0.09). Unsurprisingly, 1RM-LP and rep-80%-LP were significantly associated (r = 0.55).

Anthropometrics

The researchers found that rep-BW-PU was negatively associated with bodyweight (r = -0.55), fat mass (r = =-0.55), and lean body mass (r = -0.50) but there was no association between rep-BW-PU and percent body fat or percent lean mass. In turn, 1RM-LP was positively associated with body mass (0.55) and lean body mass (r = 0.55).

Predictive equations

Based on these data, the researchers produced an equation to predict pull ups from 1RM-LP performance and bodyweight (BW), as follows: rep-BW-PU = 0.34 x BW + 0.72 x 1RM-LP + 29.37kg. However, this equation only explained 52% of the variance in maximum pull up repetitions.

What did the researchers conclude?

The researchers concluded rep-BW-PU is significantly associated with 1RM-LP relative to bodyweight but not with absolute 1RM-LP. They noted that increasing bodyweight seems to be advantageous for 1RM-LP but disadvantageous for rep-BW-PU.

Limitations

The study was limited in that the predictive equations were not able to explain the majority of the variance in the variables being connected.