Accommodating Resistance: Is it the key to PAP (post-activation potentiation)?

A recent article was published in JSCR which I thought was very interesting and potentially useful for an athletes training regime.  The study was conducted on the effects of resistance bands added to the back squat and its ability to “potentiate” a horizontal broad jump

The authors did an excellent job defining PAP as ” a previous muscular contraction (i.e., a potentiating stimulus) may acutely enhance muscle performance in a subsequent lighter exercise, a phenomenon termed as postactivation potentiation (PAP). After completing the potentiating stimulus, 1 may be able to perform the subsequent lighter exercise at a higher velocity and accordingly power output, therefore creating a superior acute (⁷) and long-term (⁹) training stimulus.”[1]

The main downside in the past to utilizing PAP has been the long rest periods required to mitigate fatigue (the squat makes you tired, so you have to rest long enough to perform well on the explosive movement).  An example PAP protocol would look like this:

Athlete back squats 300# for 3, rest 7 minutes performs a series of counter-movement jumps

Essentially, the heavy back squat is thought to increase the performance of the following jumps (physiology remains unclear).

There are several issues with using PAP (which is why I haven’t promoted it like a lot of other vertical jump programs):

• To allow fatigue to dissipate, several minutes between sets needs to be utilized (7-8 minutes)
• Due to the long rest periods, training sessions end up being extremely inefficient (3 sets would take over 21 minutes!)
• The long-term benefits have yet to be studied
• The short-term benefits remain questionable.  Studies have been either positive or have shown no change (even detrimental with short rest).

However, a new study published in JSCR shows that utilizing accommodating resistance may be a key contributor to making PAP more efficient and thus feasible:

What the authors did [1]:

• Took 14 rugby players (average age approximately 18)
• They performed 2 heavy back squats with 70% RM bar weight + approximately 13% band tension
• Rested 90 seconds
• Performed 2 horizontal broad jumps (10 second rest between)
• Rested 90 seconds and repeated for a total of 4 sets

What the authors found [1]:

• Significant improvement from baseline in the horizontal broad jump
• Stronger athletes responded better to the contrast protocol

Why did this occur?

• The authors propose that it is possible that performing a back squat with resistance bands may be less fatiguing (not sure if I buy that)[1]
• Also, the authors note the loading pattern is nearer to the maximum (heavier) because using bands helps follow the natural strength curve of the legs [1]
• I thought of one more reason potentiation may be greater using bands, the style of the muscle contraction.  When using bands, the muscles are forced to contract in a pattern more similar to a jumping action.  This is the concept of specificity.

Overall, it is interesting and if future research confirms this study then PAP may indeed be a useful tool for coaches to include in preparation of their athletes.  It also gives us yet another reason to use resistance bands.

1.  Seitz, Laurent B., Minas A. Mina, and G. Gregory Haff. “Postactivation Potentiation of Horizontal Jump Performance Across Multiple Sets of a Contrast Protocol.” Journal of Strength and Conditioning Research 30.10 (2016): 2733-740. NSCA.