By Carl Valle
I have written numerous articles on jump testing and will likely write more in the future, but this may be the most important one for athletic development. You can look at elasticity and coordination at the same time in other ways, but nothing is more practical and useful than the Scandinavian Rebound Jump Test (SRJT for short). While it’s very similar to the Reactive Strength Index, and can be considered in the same family, the difference is its simplicity, which coaches love.
Unlike most jump tests that seem to be difficult to implement in team settings, the SRJT solves the need to get data without losing training time or fatiguing an athlete. I love the test more and more, and modified my own testing procedures to utilize it more effectively.
What Makes the Scandinavian Rebound Jump Test Special?
Getting straight to the point, this jump test is special because it tests the elasticity of athletes, at any point in their career, in a practical and safe manner. The ability to bounce efficiently and effectively is worth gold—literally—and that skill must be constantly under watch so you can help improve and safeguard it. We spend years and countless sessions trying to teach and train athletes to be more elastic, but testing it isn’t easy. I love that the test doesn’t feel like a performance test, and athletes can really display what they can do without being on stage all the time. I appreciate athletes needing some pressure and adrenaline, but having it all the time just grinds their body down.The Scandinavian Rebound Jump Test assesses the elasticity of athletes in a practical & safe way. Click To Tweet
Countless other tests are excellent for measuring power and the ability to jump far and high, but this test is the simplest way to discover if an athlete of any level can use their elastic abilities well. Many great athletes are fast, but the very best are elastic and can use ground reaction forces as a weapon, not a barrier. In summary, the SRJT is special because:
- The specificity and validity of the test are what a coach needs to know.
- Athletes of all ages and abilities can be tested, evaluated, and compared.
- Testing can be done quickly and safely, and with very little equipment.
- Programming and career development decisions are very clear after analyzing the data.
- The energy and effort spent by athletes to perform the test isn’t going to interfere with training.
- Athletes enjoy the test because it’s a great learning experience and they can feel it.
In all fairness, other tests likely provide the same benefits, but the devil is in the details. The difference—the key separation—is the way we administer the test, which makes it the leader of the pack. If I were to pick one benefit that makes the SRJT golden, it would be the elegant way it reveals what speed athletes can do with their elasticity. Other tests can show similar findings, but they are sterile and very artificial. As an analogy, the Scandinavian Rebound Jump Test is similar to learning about a tiger from the jungle rather than from a zoo. Both environments have the same animal, but the information about the tiger in the wild is far more comprehensive.
Other tests in the Reactive Strength Index “family” are valuable, but each has particular pros and cons that make it an excellent test to only perform occasionally. The Raptor Test, or the convergence of the Bosco tests and tweaking of Damian Harper’s 10/5 Rebound Test, is something I do with advanced athletes. The Scandinavian Rebound Jump Test is something I did in the past for teaching and training, but now I believe it’s worth testing year-round.
Who Invented the Test and What Is Needed to Measure It?
I credit Håkan Andersson from Sweden for putting the last finishing touch on the test; hence, the Scandinavian reference in the test name. While he was not the first person to use contact time and flight time ratios in testing sprinters, he was the most shrewd in the implementation of the test. It was his focus on effectively using a simple measure of contact time by looking at all information in training and performance that made it an innovation rather than just an iteration.
In Ireland, Eamonn Flanagan and others have also added the necessary sport science to ensure the “species” of contact time-driven tests are useful for coaches. While they do not relate directly to the test, I must praise their work because they have done so much to increase the general popularity of contact mats, IR jump equipment, and other forms of testing equipment.
Video and a contact time tool are necessary to properly appraise the jump test, as well as an athlete willing to listen and focus for a few minutes. While it’s possible to use video without a contact system, the process is slow and painstaking. For the last 20 years, I have used high-speed video to capture an array of performance measures like bar velocity and contact times, but hours of analysis eat away at your life.
When you invest in equipment, think about the value of the process, not just the cost of the equipment. Every solution has drawbacks, and cheap usually means a loss in either data quality or workflow. I find automation and instant feedback to be invaluable, but if you are without a budget, video can get you the data; just prepare to spend a lot of time and not be able to orchestrate groups in training.
How to Perform the Scandinavian Rebound Jump Test
The SRJT is very straightforward. Have the athlete continuously jump up and down, trying to bounce higher and higher so they maximize their flight time by efficiently using their contact time to get their body up. You must coach up the execution purposely, as the test requires coaching to unveil the adaptation and talent of the athlete. Unlike other jump tests that are mainly singular events, the Scandinavian Rebound Jump Test is more like a skill than a movement.Unlike jump tests that are mainly singular events, the SRJT is more like a skill than a movement. Click To Tweet
Take the best ratio or score of the test and repeat it as much as you can without making the process a burden. The best ratio of flight time to contact time will lead to one number, but remember that the goal is to bounce higher and faster. Athletes should use a stiff hip, knee, and ankle so they are testing the leg, not an individual joint system. Expect longer contact times and flight times than when doing short stiffness work with a straight leg. Some investigation into ankle jumps has been done with sprints in fine detail, but that is more a measurement of foot contribution.
Video 1. This is a typical way to assess total athletic stiffness, but other options like jumping with the hands on the hips are very useful for low-frequency approaches to measurement. The more frequent the testing, the more likely the data is useful and valid.
People commonly have a question about the contribution of arms in jump testing, since arm action is so variable that test data can look scattered. Note that what is noise to the smart statistician is really a signal to the genius coach. Arm action happens in sprinting, so arm drive and hands on hips are both equally valuable. I prefer arms for max height and body stiffness, and hands on hips for leg stiffness.
One of the biggest mistakes I see with jumping is the focus on leg action recovery versus body projection forward or up. I attribute this problem to two very common causes: the YouTube generation and the equipment used. If athletes tested more with force plates, they would understand it’s about applying force rather than finding a way to increase flight time without putting work down into the ground. The box jump addiction is another reason jump testing and training stink now, as the temptation to focus on glamour rather than results is the reason we still stagnate as a field or profession.
If you can get one principle or nugget of wisdom, it is that athletes are losing their abilities to bounce and we need to correct this trend now. Bouncing illustrates the elastic response more than jumping, as we often think about pushing with the legs versus receiving the forces with the center of mass. When we say an athlete “has great springs,” we all recognize the athlete can jump. However, we really want to say the athlete can bounce, as most of the sporting actions—like athletes dunking and athletes going up for an interception—have a preceding step or run.Athletes are losing their abilities to bounce, and we need to correct this trend now. Click To Tweet
Bouncing up and down is a general skill that is endangered because games have been mistakenly replaced by child sport. What we see now are kids that have never learned the sensation of simply bouncing up and down versus jumping up and down.
The key to the Scandinavian Rebound Jump Test is letting athletes just bounce up and down and throttle up the forces so they can achieve a peak score. Most tests use the average score and dismiss the outliers. Testing over and over reveals what an athlete can really do, by not allowing mistakes and poor familiarization to hurt the data quality. Allow an athlete to learn the test, as the measure is a valuable skill and window to adaptation. The more skilled the athlete becomes, the more likely they are to figure out how they can stiffen the joint system and use elastic energy.
How Does the Jump Test Transfer to Speed and What Sports Benefit?
Elasticity is about transferring momentum, and that’s why I believe the test transfers so well to high-speed running. As an athlete runs increasingly faster, the time frame to be productive in moving faster horizontally decreases. While having a shorter contact time doesn’t always mean the athlete is more efficient, if they are able to project themselves forward with more velocity it’s likely that the time frame becomes shorter as well. The rate of force development is starting to make the rounds again, but we know that a faster rise in force production is only valuable when the effects of the sporting action result in better performance.
Scientifically, the Reactive Strength Index’s connection to speed is fuzzy, and that’s the fault of coaches, not researchers. While I can attest that jumping well doesn’t necessarily make a sprinter fast, not jumping at all is a little too conservative and not helpful for the sport in the long run. An athlete doesn’t need to be a wizard with plyometrics to run fast, but developing elasticity should be a universal need. Unfortunately, like talent in speed, coaches are more likely to poach elastic athletes than develop them.
Due to the genetic component of elasticity, just having a great talent is enough to succeed, so our knowledge of improving that quality is very minimal. When great coaches match up with awesome talents that work hard, we will know more about how to do a better job with longitudinal elastic development. In the meantime, we can only make logical conclusions and guesswork on how elites can get better and how less-talented athletes can develop their abilities.
Video 2. Tom, the National Champion for Sweden, bounces his entire body over the hurdles while this female athlete is unable to use the ground reaction forces due to both technique and low eccentric strength. Note the typical illusion of displacement by the female athlete with an emphasis on front side recovery mechanics of the legs.
Most of the sports that benefit from elastic speed qualities are running sports, but down the road we can learn how other events or athletic activities may benefit from assessing elasticity and reactivity. Ten years ago, fascia was all the rage, and much of the excitement has calmed down now. In my experience, anatomical features of bone structure and composition of connective and neuromuscular tissues give an athlete an advantage, but preservation of joint health is what wins in the end.
What Are the Best Ways to Use the Test Results in Training?
The biggest error a coach can make is to try to change the program to improve the score. When an athlete doesn’t have a good score, trust your eyes but make sure you record carefully. Athletes who run fast may not test well, so always compare the test with actual sporting action like sprinting and jumping in games or competition.
The goal of the test is to extract how the athlete is improving or maintaining their true elasticity, not how they test better from becoming a better test taker. It is easy and emotionally satisfying to add plyometrics or even more weight training when we see poor jumping performance. An athlete may not jump well because their poor foundational set of low-level movement skills is the lowest form of plyometrics, and rushing through those will lead to train wrecks later in their season or career.
In the 1990s and early 2000s, I employed jump-testing batteries and overreacted to the scores. While nobody got hurt from overdosing on jumps, we improved a lot in our running as we became sprinters who trained like horizontal jumpers and our times paid the price. My ego misdirected the program to focus on athlete test performance because it gave me comfort to know we could max out the table; however, in our races we looked like super-athletic talents, but rookies to track and field.
My weakness as an athlete never really hampered me that much, but in this case my lack of talent in the jumping arena helped me. When I wanted to dunk, it took me years, and I was able to barely put the ball down once in my life. The improvement came slowly through experimentation in college with every gadget and magazine ad jump program available. From that trial-and-error period, I realized that my foundation was shallow and I skipped steps, and adding plyometrics to a bad jumper is not the solution.
Plyometrics are jumping exercises that exploit the stretch-shortening cycle, and athletes need landing and stiffness training. We lack rudimentary exercises like sticking landings with nearly silly tiny heights. Skipping rope and ricochet jumps are about building a fast superhighway of the brain and body, and adding force too soon is as bad as slapping too much weight on a barbell.
I have shared a few jump exercises in the past—many of them stolen from the “LSU School”—but it’s better to teach skills than just do drills. A good tuck jump done in place 10 times will never get the viral response on social media, but learning to touch the ground quickly and use the momentum down to come up is a winner. Rapid stiffness is about learning to alternate between isometric bracing and fluid movement. Great athletes do this without coaching, but great coaches get athletes to do it with the right programming.
Elasticity is a skill you can do nearly daily, so make sure athletes have a huge base of low-amplitude skills that encourage rapid stiffness and joint control mastery. I struggle to develop this, but I feel much better knowing how I am doing instead of not testing and keeping my head in the ground.
When Is the Best Time to Perform the Test in Practice?
Three important periods exist when implementing any jump test, and the SRJT is best placed at the right time during the phase, the week, and the practice session. I have spent seasons not testing elasticity at all, save for a few jump tests done sporadically. At lower levels such as high school, we never did elastic testing but did do elastic training. I didn’t need a contact grid to know whether an athlete had poor abilities or was blessed, but I did miss not knowing if an athlete was improving.Testing any type of neurologically demanding training must be done on the freshest day possible. Click To Tweet
I have recently found that testing any type of neurologically demanding training requires that it be done on the freshest day possible, otherwise the data just shows fatigue or eccentric damage. I don’t recommend this as a sole assessment of readiness, but if an athlete is really testing well on any reactive strength test, I have never seen a poor speed session done right after. True, my own empirical evidence isn’t enough to show that the RSI family of tests means a great ratio equates to fast running, but if you are addressing speed and elasticity improves significantly, it is likely the athlete is resting and recovering well or they are adapting to the training as expected. Doing any elasticity testing when tired only reinforces bad habits and even increases fatigue.
From a little experimentation with micro-tapering training weeks, I have also seen athletes unload too much training and show up flat, meaning they reduced volume and intensity so much they lacked that snappy elasticity needed for fast running. Right now, I like testing after a recovery cycle and early in the week when an athlete has no cumulative fatigue. I also test early in the session, sometimes before and after a warmup, to see if we are doing too much in our preparation for speed work.
My only warning with testing is that you can’t allow athletes to think that the score means they can run fast if they are doing it before a fast session or that they need to go fast if they fire off a good score. Again, I only have a few years under my belt testing this properly, and a small population of data points, but my network of coaches all swear by the importance of having a good bounce. What convinces me that this test is important are the years of high-speed video showing that without the ability to get off the ground fast with high rates of force and propulsive strength, athletes can’t enter international races.
Team sports may not have the same desperation for speed, but testing can show if an athlete is running slow from injuries and lack of speed and jump training. Athletes who live too much on the strength side will improve early and produce acceleration early, but never have closing speed.
One Last Point About Improving Elasticity
The relationship between contact time and flight time certainly exists, but don’t look at the numbers as determining who gets drafted or finds their way onto the podium. With all of the science exploding on the research side, wisdom is crucial to ensure quality information is applied properly. Elasticity is an instrumental part of performance, and needs to respected by ignoring it or overloading it to the point of exhaustion. The numbers will fall into place with any of the RSI tests, including the Scandinavian Rebound Jump Test. Have faith and confidence by assessing training over the course of the season, and remembering to time split and apply other performance tests.
The irony is that focusing on getting better numbers on the test will result in smaller improvements, as elasticity takes time and is also genetic. A smart goal is to maximize what an athlete has and not fight their DNA, but don’t let those with fewer gifts or talents settle for a poor bounce.