Postactivation potentiation can counteract declines in force and power that occur after stretching

Abstract

Stretching can decrease a muscle's maximal force, whereas short but intense muscle contractions can increase it. We hypothesized that when combined, postactivation potentiation induced by reactive jumps would counteract stretch-induced decrements in drop jump (DJ) performance. Moreover, we measured changes in muscle twitch forces and ankle joint stiffness (K ) to examine underlying mechanisms. Twenty subjects completed three DJs and 10 electrically evoked muscle twitches of the triceps surae subsequent to four different conditioning activities and control. The conditioning activities were 10 hops, 20s of static stretching of the triceps surae muscle, 20s of stretching followed by 10 hops, and vice versa. After 10 hops, twitch peak torque (TPT) was 20% and jump height 5% higher compared with control with no differences in K . After stretching, TPT and jump height were both 9% and K 6% lower. When hops and stretching were combined as conditioning activities, jump height was not different compared with control but significantly higher (11% and 8%) compared with stretching. TPTs were 16% higher compared with control when the hops were performed after stretching and 9% higher compared with the reverse order. K was significantly lower when stretching was performed after the hops (6%) compared with control, but no significant difference was observed when hops were performed after stretching. These results demonstrate that conditioning hops can counteract stretch-related declines in DJ performance. Furthermore, the differences in TPTs and K between combined conditioning protocols indicate that the order of conditioning tasks might play an important role at the muscle-tendon level.

Time to Differentiate Postactivation “Potentiation” from “Performance Enhancement” in the Strength and Conditioning Community

“…In fact, the extent of potentiation for contractile properties ranged from 4 to 188% immediately after the conditioning contraction, with a progressive decline over time ([ 14 , 19 , 21 , 24 – 26 ]; Table 1 ).…”

“… CC conditioning contraction Specifications based in the relevant literature ([ 9 , 14 – 16 , 18 , 19 , 21 , 24 – 26 , 36 , 53 , 56 ]) …”

“…The corresponding effect sizes (ES) were medium-to-large (0.54 ≤ ES ≤ 1.37) and small-to-large (0.22 ≤ ES ≤ 0.87), respectively. Additionally, there is evidence that repetitive hopping induced significant and large-sized gains in plantar flexor TPT (1.47 ≤ ES ≤ 3.26) and drop jump height (1.36 ≤ ES ≤ 6.75) 30 s following the conditioning activity in recreationally active individuals [ 26 , 42 ]. Thus, the authors concluded that twitch PAP effects contributed to gains in jump performance [ 26 , 38 , 41 , 42 ].…”

“…Additionally, there is evidence that repetitive hopping induced significant and large-sized gains in plantar flexor TPT (1.47 ≤ ES ≤ 3.26) and drop jump height (1.36 ≤ ES ≤ 6.75) 30 s following the conditioning activity in recreationally active individuals [ 26 , 42 ]. Thus, the authors concluded that twitch PAP effects contributed to gains in jump performance [ 26 , 38 , 41 , 42 ]. However, statistical associations between pre-to-post-exercise changes of twitch contractile properties (i.e., mechanistic PAP approach) with strength, power, or speed measures (i.e., performance PAP approach) are inconsistent in the literature.…”

Comparison of Loaded Countermovement Jump with Different Variable Resistance Intensities on Inducing Post-Activation Potentiation

“…In addition to improving jump and sprint performances [5,6,17,18,23,29], PAP induced by performing plyometric exercises has also been reported to improve throwing (shot put, hammer throw, discus and javelin) [16] and judo performances [20]. It has even been suggested that that plyometric might be more effective than a traditional resistance exercise in inducing PAP as plyometric exercises are associated with preferential recruitment of type II motor units, which is the mechanism underpinning PAP [25].…”