The Effects of Ballistic vs. Accommodating Resistance Barbell Training on Bar Speed Metrics

“What is the most effective way to make an athlete more powerful?” This was the question that sparked the idea to conduct a case study among our male multisport high school athletes. We chose to compare two methods that both fall under the “dynamic effort” umbrella. The first was a more traditional means of training for power, using bands for accommodating resistance. The second method was a more novel training method, launching the bar using a self-spotting rack called the XPT half rack. (Check out a full review of the XPT here.)

These two methods allowed us to program the same movements with the same volume of sets and reps, as opposed to other methods (such as contrast training) that would make it more difficult to ensure equivalent volume between groups. We also chose not to use any Olympic lifts or their derivatives since they are different movements altogether.

The question ‘what is the most effective way to make an athlete more powerful?’ sparked the idea to conduct this case study on two dynamic effort methods of training, says @Brandon_L_Pigg. Share on X

When discussing training methods, it is difficult to truly say one is better than the other. There is always an argument from silence that even if you saw better results using one set of methods one year than you did with other techniques in previous years, you cannot say that one is definitively better than the other since other external factors may have influenced the outcomes.

This problem is the foundation of all research. It is also why we wanted to conduct this case study and see which method would yield better results when all other external factors were equal. While this case study does not meet the standards of peer-reviewed literature—as I will discuss in the methods section below—it does show reasonable expectations for results between the two methods.

It should be noted that while the overall format of this article will be similar to that of a peer-reviewed research paper, I am leaving room to inject my own opinions and experiences alongside the data since this was an informal, in-house case study.

Background

With the increased accessibility to technology that allows for velocity-based training (with devices such as the Vmaxpro and GymAware), many coaches have begun to pay closer attention to dynamic effort training methods. Training for power typically involves:

• Moving a lighter load fast, with or without accommodating resistance like bands or chains.
• Ballistic methods with lighter implements such as medicine balls or weighted balls.
• The use of weightlifting movements and their variations.

Some heavier ballistic methods are also common, such as a barbell jump squat or trap bar jump. Of the two, the trap bar jump is probably preferable because the barbell squat jump has a component of dynamic spinal loading during the landing. There also aren’t any common means for upper-body ballistic barbell movements. While heavier ballistic methods were previously limited in number, accommodating resistance has historically been a popular option due to its association with Westside Barbell and its low-cost barrier to entry.

One of the main proposed benefits of using the XPT trainer: you can accelerate throughout the entire range of motion and ballistically launch the bar instead of slowing it down, says @Brandon_L_Pigg. Share on X

While accommodating resistance has shown solid results for barbell lifts, some coaches feel that since you have to eventually decelerate at the end range of motion of the lift, you are actually teaching the brain to do the opposite of what it does during natural movements like sprinting or jumping. This is one of the main proposed benefits of using the XPT trainer: you can accelerate throughout the entire range of motion and ballistically launch the bar instead of slowing it down. If you would like to read more about what training with the XPT looks like, you can view some demonstrations here.

Methods

Recruitment and Selection

This is one area where we deviated from standard research operating procedures. Under normal circumstances, participants would have shown interest after being recruited and joined the study at their own discretion. Groups would have either been completely randomized, or they would have been formed so that, after pre-testing, the average metrics between both groups would be similar.

As a former research assistant, I fully understand the need for randomization to avoid bias or juicing one group’s results over the other. As a high school strength and conditioning coach, I’ll plead my argument for why we didn’t do this.

Under normal research circumstances, participants in a study like this would be recreational athletes at best and, at worst, couch potatoes who knew you needed more participants. This allows the researchers to set standards that any exercise or training during the duration of the study should be limited to, or non-conflicting with, the training done within the training intervention sessions. With high school athletes, this is not the case. As for recruitment, it’s hard to set exclusion criteria that say, “Naw, bruh, we can’t trust you.”

In the high school setting, the bandwidth of maturity has a wide span. We chose to hand-select 14 male athletes who had multiple years of training experience and whom we felt were all capable of completing the study with good effort and good attendance. Instead of randomizing them, we chose to separate them so that both groups had an equal number of athletes in in-season sports, off-season sports, or preparing for college athletics. While we could have tagged each of them with one of the variables and randomized from there, we chose hand selection because the athletes trained during different class times, and we wanted to ensure there was enough rack availability for each class. Not being able to limit these extracurriculars was a limitation of this case study, but balancing each group was the closest we could come to washing these variables out.

Pre- and Post-Testing

Both pre-testing and post-testing were conducted on the XPT half rack using a Vmaxpro to capture bar speed metrics. The metrics collected for analysis were peak power, average power, peak velocity, and average velocity. Metrics were collected on a bench press launch at 40% and 60% of bench press one rep max (1RM) and on a box squat launch with 60% of back squat 1RM. Percentages were selected to be between the traditionally accepted peak power range of 40% and 60% 1RM. The pre-testing was conducted after one week of familiarization with launching the bar on both bench presses and box squat jumps.

In testing, each participant completed two repetitions (reps) of the bench press launch at 60%, followed by two reps of the bench press launch at 40%, and then finally two reps of the box squat launch at 60% 1RM. As each rep was completed, I collected results on a data sheet for each subject (figure 1).

Intervention Design

Each group trained in class as usual (twice a week for 60 minutes). Lifting sessions were conducted after a dynamic warm-up, resisted sprints, medicine ball throws, hurdle hops, and three 15-yard sprints, which was the training format for the preceding five months leading up to the study. Both groups were given a one-week introductory period before pre-testing. This allowed the athletes to familiarize themselves with the XPT and what it feels like to actually launch a barbell on a bench press or squat.

This familiarization period was essential, as some athletes were initially tentative and needed time to trust the machine. The banded group always used a red Westside Barbell band anchored, so the bench press was approximately 60 pounds higher than the bar weight at the top, and lower-body movements were around 100 pounds higher than the bar weight at the top. Individual differences may have occurred due to height or limb length.

The lifting protocols for each group were as follows (sets and reps are listed as sets x reps):

Banded Group

Day One:

Banded Bench Press

• 40% Bench Press 1RM 3 x 3

Banded Box Squat

• 40% Back Squat 1RM 3 x 3

Chin-ups

• Body weight 2 x 2–3 reps in reserve

Landmine RDL with Viking Press attachment

• 8–12 reps with two 45-pound plates loaded on the bar

Day Two:

Banded Bench Press

• 60% Bench Press 1RM 3 x 3

Banded Split Squat

• 40% Back Squat 1RM 3 x 3

TRX Rows

• Body weight 2 x 8–12 reps

Dumbbell RDL

• Weight that allows 2 x 6–8 reps for each leg with 2–3 reps in reserve

XPT Group

Day One:

Bench Press Launch

• 60% Bench Press 1RM 3 x 3

Split Squat Launch

• 60% Back Squat 1RM 3 x 3

TRX Rows

• Body weight 2 x 8–12 reps

Dumbbell RDL

• Weight that allows 2 x 6–8 reps for each leg with 2–3 reps in reserve

Day Two:

Bench Press Launch

• 45% Bench Press 1RM 3 x 3

Box Squat Launch

• 45% Back Squat 1RM 3 x 3

Chin-ups

• Body weight 2 x 2–3 reps in reserve

Landmine RDL with Viking Press attachment

• 8–12 reps with two 45-pound plates loaded on the bar

For the XPT group, percentages were selected to match the average velocity of banded movements using pilot data conducted with the Vmaxpro. These two days were repeated using the same loads for the duration of the study, which was four weeks long.

Exclusion Criteria and Dropouts

The criteria for being excluded from the study without completion were as follows:

• Poor attendance resulting in fewer than six completed sessions over the four weeks of training.
• Injury.

Each group began the intervention with seven subjects. Three subjects were excluded from post-testing due to attendance, one was excluded for an injury, and one dropped out due to a college strength coach requesting he start doing a new workout program in class. This left the Banded group with five participants who completed post-testing and the XPT group with four participants who completed post-testing.

Statistical Analysis

P-values were calculated using Google Sheets’ T-Test function. We used a paired samples t-test. This is input with the function =TTEST(Range 1,Range 2,2,1). Range 1 is the pre-test values; range 2 is the post-test values; the “2” means it is a two-tailed test; and the “1” selects a paired samples t-test.

Results

The results were as follows. Power metrics are reported in watts. Velocity metrics are recorded in meters per second. Statistically significant measures (p-value < 0.05) are highlighted in yellow.

Statistical Significance

Percent Change Pre/Post

Discussion

The results were a tale of two different beasts. Both groups saw solid improvements in some or all bench metrics. Neither group saw meaningful improvements in the box squat metrics. While only six total metrics had a p-value < 0.05 across both groups, I would focus on percent changes from pre/post.

Given that these athletes completed 6–8 sessions, seeing changes of this magnitude in the timeframe equivalent of a single block of training is quite impressive, says @Brandon_L_Pigg. Share on X

Looking at the percent changes, I think any reasonable strength coach would say that the XPT group saw meaningful improvements in all metrics for the bench press, and the Banded group saw significant improvements in average metrics for the bench press. On each of the metrics, the XPT group had between a 25.54% and 48.79% change in both the 40% and 60% 1RM bench press launch. While the Banded group did not do nearly as well in peak metrics for the bench press, it saw impressive jumps in the average categories with percent changes between 26.03% and 56.69%. Given that these athletes completed between six and eight sessions, seeing changes of this magnitude in the timeframe equivalent of a single block of training is quite impressive.

As for the box squat launch, the XPT group effectively saw no difference aside from average power, and the Banded group saw small changes in power. There are a few potential reasons for this discrepancy between the bench and squat results. As a whole, the previous training probably develops lower body power more so than upper body power. The only real upper body power work we did in previous blocks was medball work and landmine jerks. With all the sprinting, resisted sprinting, and jumping we do, there was likely just less room to develop lower body power than there was for upper body power.

As to why I think the XPT group performed worse on the squat compared to the Banded group, I think it may have been in part to some of the kids having experience with the rack. The half rack is not as tall as the full rack version of the XPT rack. You have about 6 feet of space from top to bottom, which leads to the bar smacking the top of the rack on any type of jump with a bar on your back or in a rack position.

There were also a handful of incidents where kids just locked up and death-gripped the bar, preventing the catching mechanism from engaging and letting the bar freefall after the jump. I believe this could have resulted in some hesitancy to go all-out in both training and post-testing. I think this issue is easily avoided with the full rack.

The XPT brand is also in the process of releasing adaptor kits that can fit onto common brands of power racks, allowing you to have self-spotting capabilities on your current racks. Given the XPT group’s results in the bench press, I would have definitely liked to have conducted the study on one of these taller models to test if my hypothesis of hesitancy is correct.

Future case studies should potentially consider having a Banded XPT group to see how adding accommodating resistance to a ballistic launch could impact testing outcomes. It should also be noted that the brake handles on the XPT increase the diameter of the bar by about 0.5 inches. To equate this, the banded group should use an equivalently sized Fat Gripz-type device on all upper body lifts to tease out any effects that could come from a different bar size.

Given the large response on bench press metrics, it could also be worthwhile to run an initial block using neither ballistic nor accommodating methods. This would provide measures to eliminate any murkiness as to whether or not previous programming simply failed to address upper or lower body power and left a higher or lower ceiling for development.

While this is just pilot data in a small cohort of participants, I believe there are a few practical takeaways. First, each coach should occasionally perform a SWOT analysis of their weight room and what they are and aren’t able to train. (A SWOT analysis means to look for strengths, weaknesses, opportunities, and threats that all need to be addressed.) My approach to programming is to always attempt to invest time in exercises that will give the athletes the biggest return on their effort investment. Your time, space, equipment, and other logistical restraints will always determine much of what you can do, but this is why the SWOT analysis is so critical for each coach to perform instead of copying and pasting another coach or program’s training.

As I mentioned, since we performed sprints and resisted sprints year-round, our lower body power may have already been one of our strengths. While medicine ball training and landmine jerks are great for a number of reasons, it is clear that there was a significant opportunity to improve vertical pressing power in our athletes.

SWOT analysis is so critical for each coach to perform instead of copying and pasting another coach or program’s training, says @Brandon_L_Pigg. Share on X

I have moved on to a new school this current school year, which has impacted my programming. We do not have Exer-genies or other means of performing resisted sprints on our speed days. This means that there may be an opportunity and need to increase lower body power through other means, so we have incorporated more speed squats, split squat jumps, trap bar jumps, and trap bar speed pulls in our training.

Recognizing that upper body horizontal pressing power was already a big opportunity in the previous setting, I suspect it will be even more so at my new school. We do not have bands or a good space to throw medicine balls, so speed bench and more frequent jerk/push press variations have been integrated into our training. Those programming methods reflect the restraints of our program.

Some methods may be more efficient at yielding results than others, and acquiring the means to perform them should impact how you budget and allocate funds once you’ve identified weaknesses, opportunities, or threats to your current programming. This is an ever-evolving process for all coaches, and I hope case studies like this one will help us all grow in that process.

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