In American football, we’re experiencing a pendulum swing that’s moving away from long duration shuttles toward short duration repeated sprints that replicate the demands of the sport. I don’t write this article to be contrarian; rather, I suggest an objective way to determine a football player’s level of “fitness” and ability to complete the demands of the sport. I hope this brings some balance to the conversation about how we objectively measure the fitness we’re trying to create in our athletes. After all, much of what we’re arguing about is the training of fitness, not the evaluation of it.
I want to thank Donnell Boucher (Assistant AD & Head Strength and Conditioning Coach at the Citadel) for eloquently capturing my thoughts and arguments through a series of tweets on the topic that I’ve been thinking of for some time and that pushed me over the edge to write this post.
The Age Old Argument on Conditioning
If you’ve been following social media conversations this summer, you’ve seen a lot of discussion about the training and testing of energy systems for American football. As we do on social media, we’ve seen some coaches blast the common practice of the 16 x 110 timed test and doing repeat 300-yard shuttles. They suggest replacing these with repeat sprint ability (RSA) tests that are similar to football. Although one could argue that RSA tests are an improvement over the 16 x 110s, both serve more as screens rather than tests.
Both have pass/fail criteria that tell us if an athlete can complete a certain level of output. A player’s inability to achieve certain levels might be due to physical qualities that can’t be teased out in either of these “tests.” One of the strengths of an RSA-based test is the specificity and ecological validity, though the most specific test would be the game itself. But what it gains with ecological validity and specificity, it loses in physiological specificity and validity.
I summarize my arguments for using the beep test with football players in three evidence-supported points, which I’ll discuss in detail in this post. If you follow the logic, I expect you’ll agree that, in a comprehensive battery of tests to evaluate the overall athlete, the beep test fits right in with common testing practices, especially in football.
First, football is characterized by repeated bursts of high-intensity efforts. Second, aerobic fitness can enhance recovery between bursts of high-intensity efforts. Third and finally, the beep test reliably measures an athlete’s aerobic fitness and, accordingly, their ability to recover between bursts of high-intensity efforts.
When we evaluate what an athlete needs to become highly successful in a given sport, we must understand the demands of that sport. Higher-level football players tend to have greater levels of strength, power, vertical jump, broad jump, acceleration, and top-end speed. Jay Hoffman showed this in a few papers. And it should be intuitive to understand how higher levels of these physical capacities are valuable in sport.
Even at the NFL level, there is a preference for offensive linemen who have faster 40s, which is not the main requirement for their position. The demands of the game are not really in question here, though they’re often highlighted to explain how we should train and test our athletes. Most of the literature analyzing the demands of football says something along the lines of:
- Average play length—offense and defense ~5 sec, special teams 8 sec
- Recovery between plays—30-35 sec (no stoppage), 80-112 sec depending on the level of play
- Plays per drive—6-7 on average
- Average # of drives—11-13
- Average work to rest ratio—1:5-1:6
Overall, football players do brief bursts of high-intensity work followed by rest that gives them incomplete recovery during a series; they can recover fully between series. A study by Pincivero (1997) suggests that phosphocreatine (PCr)is the predominant energy system. And we know that, as incomplete recovery accumulates between bursts of high-intensity efforts, there is a greater mix of energy systems.The strength of a player's aerobic system helps them recover between plays on long drives or an up-tempo offense, says @ERichStrength. #BeepTest Click To Tweet
It’s also important to highlight how the aerobic system contributes to recovery from high-intensity bursts. Aside from extended rest (which a player might get between series), what will help a football player recover between plays and, more importantly, between plays on long drives or an up-tempo offense? This, of course, is the strength of the aerobic system.
The Aerobic System: A Reality for American Football
Coach Boucher was nice enough to highlight a few papers explaining the importance of a strong aerobic system for a football player. One of them looks at phosphocreatine re-synthesis following intense exercise, and makes two important points. First, “maximizing the rate of PCr re-synthesis during a brief recovery period will be of benefit to an athlete involved in activities which demand intermittent exercise.” Second, “given the importance of oxidative phosphorylation in the re-synthesis process, those individuals with an elevated aerobic power should be able to re-synthesize PCr at a more rapid rate.”
Another study looking at how aerobic fitness affects recovery summarizes that “aerobic fitness enhances recovery from high-intensity intermittent exercise through increased aerobic response, improved lactate removal, and enhanced PCr regeneration.” Combining the evidence from these two articles suggests that having a strong aerobic system plays an important role in how quickly a football player recharges their PCr stores between plays and limits the contribution from less powerful energy systems.
Finally, if we can agree that football players go through repeated high-intensity bursts of effort separated by incomplete recoveries—and evidence establishes that a strong aerobic system can affect how much PCr is available for repeated high-intensity efforts—we should be able to agree that a well-developed aerobic system is beneficial for football players.
The most logical option to determine how well an athlete recovers between plays is the beep test; it’s specific to the strength of the aerobic system and has a high laboratory validity. It also fits in nicely with how we traditionally test our football players.
Consider a collegiate football program’s conventional tests and what they’re supposed to tell a coach:
- 1RM bench press—the expression of maximal upper body strength
- 1RM squat/deadlift—the expression of maximal lower body strength
- 1RM power clean —the expression of explosive power
- Vertical jump—the expression of maximal vertical explosive power
- Broad jump—the expression of maximal horizontal explosive power
- 40-yard sprint (with 10-yard splits)—the expression of start, acceleration, and top-end speed
What do all these have in common? A few things. First, they look at maximal expressions of physical qualities. Second, none of the strength exercises appear in a game (the old quote “you’ve never seen a bench press on the field” fits here). Third, other explosive measures rarely, if ever, appear in a game (except maybe a max vertical jump on a Hail Mary or an untouched long run).
We talk about how our role is to train general qualities that transfer to the game. So, when it comes to energy systems, why all of a sudden do we need our energy system work to be this super-specific thing? I’m not sure where it comes from. Is it because sport coaches want a test? Or do coaches think that, if we do a beep test, our athletes will abandon all of our current training programs and become cross country runners?
In short, we like our tests to be cut and dry. We like them to measure a single and very specific item that makes up a small piece of the successful athlete puzzle. Although people like Dr. Mann have suggested that offensive linemen fire out at 1.6 m/s and then move at 0.6 m/s, we don’t suddenly create testing batteries to see how much our athlete can squat from a pin at 1.6 m/s and how much they can bench press at 0.6m/s.
We generally accept that if someone has a higher level of maximal strength, they will perform better at these specific components of their sport because sport and skill work is where our general qualities transfer to. Again, we don’t seem to trust this with the aerobic system. The downside to the majority of the fitness tests that people use or suggest (110’s, RSA) is that they don’t objectively quantify where the weak link is. In these tests, it could be acceleration, COD, top speed mechanics, etc.The #BeepTest measures the strength of a football player's aerobic system & helps identify any weak links on the field, says @ERichStrength. Click To Tweet
For those who use a comprehensive battery of these tests, adding the beep test will give objective data about how strong an athlete’s aerobic system is. And you can analyze this in comparison with acceleration and top speed to see what the limiting factor could be on the field. In this instance, we should measure aerobic power.
Appraising Aerobic Power with the Beep Test
The gold standard for measuring aerobic power is in the laboratory using a graded treadmill or bike where we increase the speed or load until failure. At the same time, we measure the gasses going in and out of the athlete’s mouth to determine the amount of oxygen consumed at maximal exercise levels. Unfortunately, it’s not feasible to put a team of 100 football players in a lab and individually crank up the speed to find out their VO2 max.
Fortunately, the beep test developed by Leger (1988) is a reliable way to determine one’s maximal aerobic power with reliability coefficients ranging from 0.89 to 0.95. Its main benefit is that it’s easily administered in a team setting. We’ve had 20-30 athletes at a time perform the test. With our football team, we do three waves (skill, box, and line), allowing us to get everyone through in 45 minutes. It makes it easy to set standards (because of the levels) and allows for athletes to see progress (progressing from an 8.01 to a 9.01).
It’s also very much like the 1RM tests we enjoy in the weight room. Take the 1RM bench press, for example. The protocols suggest starting with a light weight, do some reps, and slowly add on more and more weight until you can’t add any more. This continues until an athlete gets a very heavy load and has to grind through the rep to complete it. Then, they try a little bit more while their teammates surround them, scream encouragement, and watch as they struggle to get the bar up and inevitably fail.
The beep test has exactly the same protocol. A player starts at a slow speed and comfortably works up until it gets harder and harder. As it gets harder, they have to focus more, dig in, and try to make the next beep. If they miss a beep, that’s okay; it just means that they must dig in even more and make the next one to get back in the race.
With our football team, when we get down to the last few guys, teammates surround them, create a tunnel, and cheer them on to the next beep. The atmosphere is very similar to the end of a weight room testing session when athletes huddle around the strongest guy to help keep them going. At the end of the day, the 1RM bench press and the beep test may use different energy systems, but they both give us coaches an objective piece of information about the physical ability of our athletes in these singular qualities.
Test American Football with Purpose Using Science
I hope you followed the logic explaining why the beep test might be the best tool for measuring fitness in football players. The beep test connects the dots of the demands of the game and recovery between plays of maximal acceleration, speed, and strength, and it objectively quantifies a physiological output similar to our weight room tests.
That being said, just because an aerobic test could be useful doesn’t mean we should try to improve it using purely aerobic means. The science confirms that we can improve aerobic power through short, high-intensity bouts of effort. It’s the same as when we’re looking to improve strength in the weight room or vertical jump—we don’t do pure one-rep max work all off-season or put our athletes on a jump program. We can argue about the best ways to do this (shuttles vs. tempos, etc.). Many roads lead to Rome, and the beep test lets you know where you stand on the path.