Force Science News #162:

Comments, questions on Force Science study of officer exhaustion

Editor’s note: Have a question for Force Science? Drop an e-mail to: and we may answer it in an upcoming FS News article.


Readers of Force Science News have responded with a variety of questions and comments to our report regarding the recently launched study of officer-exhaustion thresholds and the impact of all-out fighting on memory [see Transmission #159, “Unique new Force Science study tests officers’ endurance in fights,” sent 9/24/10].


Below is a representative sampling of emails that hit our in-box, along with responsive comments from Dr. Bill Lewinski, who led the study on behalf of the Force Science Institute. Results of the research are being analyzed and are expected to be reported shortly.


Letters have been edited for brevity and clarity. Also note the inquiry at the end regarding our review in Transmission #160 of The Invisible Gorilla, a new book about common memory traps.



 “Your subjects knew it wasn’t real”


Your test on exhaustion and memory can only hope to simulate a fraction of what goes through the mind and body of a police officer when faced with a fight-to-the-death scenario. Your subjects knew they were not going to die if they gave up. They may have been physically exhausted, but in the end, they knew it was not real.


As a trained martial artist with over 40 years’ experience, I do not get all hyped-up when confronted by a life-or-death fighter or just a knucklehead who has had too much to drink. I have been a strong advocate that police officers need 10 times as much training using their hands to subdue a suspect as they do with shooting their firearms. After all, they will be physically subduing many more suspects over the course of their careers than they will be shooting at them.


Most suspects are dead tired in less than a minute of heavy exertion. When an officer knows he/she can handle a suspect’s initial surge, the subject is relatively easy to cuff, search, and transport.


Your study is an excellent first step in determining the limits of an officer’s physical endurance and mental recall, but keep the above mentioned points in mind.


Benjamin Chamble (ret’d, Connecticut SP)

Law Enforcement Professional

173 Airborne Combat Brigade Team, 1st/503rd Battalion

Wardak Province, Afghanistan


Dr. Lewinski responds: You’re right: The officers knew it wasn’t for real. But athletes in competition will dig really deep even if it’s not a life-or-death situation. The same can be said for the officers in our study who were under intense performance scrutiny and pressure. Their average high pulse during the bag blitz was 180, with many registering as high as 200 bpm, indicating exceptional effort.


I agree wholeheartedly that in many struggles suspects run out of gas as they exert themselves to get away, resist, or assault an officer. This can then allow a skillful officer to gain control late in the struggle. The question I have is this: How can an officer acquire that level of skill when the average academy in this country provides no more training in empty-hand control than a junior high school wrestler typically gets in wrestling techniques before going into his first match? There’s a disparity between the training we provide and the expectations we have for officers’ performance.



Wouldn’t exhaustion points be vastly different among officers?


It seems to me that the continuous hitting of a heavy bag would affect memory but the point of exhaustion would be vastly different for each officer.


I work out on the heavy punching bag 3 times a week and it is very different from any other kind of training. I have seen cross-trainers who run, swim, etc., but cannot hit that bag for 3 minutes continuously. One of the reasons is that they must learn to breathe properly or they exhaust themselves very quickly.


The object of winning a fight on the street is to fight smart and not exhaust yourself in the first 3 minutes. I realize that, in some cases, a person high on PCP or other like substance will push you out of any effort to pace yourself, but it still seems to me that the point of exhaustion would be very different for officers, based on their preparation, mind-set, and level of physical fitness.


Lt. Jim Ponzi, (ret’d)

Denver PD

Professor of Criminology, Regis University


Lewinski: We are aware of the differences in physical conflicts and officer fitness levels, as well as the need to “fight smart.” The intent of the study was not to replicate any particular conflict but to attempt to confirm a typical exhaustion point for an officer engaged in a very intense conflict and to assess the impact exhaustion has on the absorption and recollection of information acquired before, during, and after the event.


The final results are not yet compiled, but preliminary analysis indicates that regardless of fitness level, all-out exertion (as contrasted with a paced training workout) can only be sustained for a short period of time. The participating officers’ fitness level certainly influenced the intensity of the effort they were able to exert, but regardless of fitness everyone eventually ran out of gas—and all did so in under 1 minute, with significant changes beginning to occur at 30 seconds.



Did physical training mode affect performance?


Did you ask the participants their current fitness level or preferred type of physical fitness? It would be interesting to see if their preferred training affected or enhanced their ability to complete the tasks. It would also be interesting to see the difference in lactic acid buildup in those who perform traditional exercises vs. those who perform the CrossFit/Mixed Martial Arts-type workouts.


Spcl. Agt. Jonathan Madore

Inspector General’s Office of Investigations

U.S. Dept. of Health & Human Services


Lewinski: Yes, we acquired demographic data that included the officers’ exercise type sand fitness scores. The officers’ agency conducts an annual fitness test for most personnel and those scores are being included in our analysis.



Report written after intense fight becomes issue at trial


Promoted to sergeant after several years working narcs, I was pretty confident I could handle anything on patrol. My first week back, I heard one of my officers go in pursuit of a domestic violence suspect who was on a motorcycle on the freeway.


This was one dangerous dude: former Marine, multi-level black belt, and Hollywood stunt man, but I didn’t know that. I caught up with him when he stopped on a dead-end street.


When I grabbed his left wrist, he spun around, taking a martial arts stance. I took a 2-handed swing with my baton at his left elbow at about half-power. Just as I was making contact, he delivered a lunge-punch to my chin.


This dazed me a bit, but I kept my head in the fight and knocked his helmet off with my right arm. He grabbed my sidearm and I grabbed his hand to prevent him from snatching it. I then swept his legs and took him to the ground.


We wrestled for what seemed like an eternity, during which time he attempted an eye rake and I was slamming his head into the ground, which unfortunately was soft dirt and leaves. Finally the original pursuing officer showed up and we were able to take this guy into custody.


At trial, the suspect testified that he considered his actions self-defense and would have shot me if he had gained control of my gun. His lawyer pointed out that my testimony was different in several aspects from the report I wrote the morning of the incident. I explained that I had been dazed at that time and my report reflected my condition. I said I had plenty of time since the incident to review what had occurred and I was confident that what I had testified to was accurate. The jury believed my explanation and found him guilty.


That encounter affected everything about how I approached people at work. I learned never to underestimate anyone.


I think your study might assist an officer who has to testify before a jury as I did.


Det. Sgt. Gary Marshall (Ret.)

Santa Paula (CA) PD



Information sought on advantage of training under stress


In the Netherlands we train police cadets under stress and are always looking for new ways to make their performance on the street better and safer. The research you are conducting can be very valuable for our students.


Recently the Dutch police force published a book about training under stress and the differences between a group trained without stress and one trained under stress. We believe that training under stress will improve shooting skills and lead to better performance, but there has not been scientific proof, at least not in the Netherlands.


Can you advise us of such information? We also would like to know for how long the advantage of training under stress will last.


Olaf Sichterman

Tactical and firearms instructor

Police Academy of the Netherlands


Lewinski: I have been aware of your research for several years and admire the effort you are making to add a solid research basis to training.


We know that training under physical stress will challenge officers and is a step toward preparing them for real-world encounters. But I am not a fan of simply stressing an officer out during training. The key in stress inoculation, as your study suggests, is to help an officer control his or her emotional and attentional processes during a crisis encounter so they can focus on what they need to do to respond to the threat. As a foundation, of course, they must have the skills needed to operate at that level of challenge.


Scientific data regarding stress training in the police world is sparse at this point, but your research and ours is moving us closer to useful answers. Meanwhile, it is safe to say that no benefit of training lasts indefinitely. Professional skills and stress management require regular and realistic reinforcement to avoid dangerous deterioration.



In addition to correspondence about the study on exhaustion and memory, we received the following inquiry related to Transmission #160 [“ ‘Mind traps’ that can trick you and those who judge your actions,” sent 10/9/10]:


Memory shortcomings and the lie box


What impact do the phenomena regarding faulty memory described in The Invisible Gorilla book have on polygraph results?


Frank Coggins

Manager, Office of Audit & Inspection

Texas DPS


Lewinski: When it comes to memory, your genuine perception is your reality. If you truly believe that you did—or did not—witness or experience something, your belief should register as truthful during a polygraph exam, even if your recollections do not jibe with reality.


However, if you are attempting to be deceptive by fabricating a false “memory,” you are not likely to be successful in your lie, provided that the machine is functioning properly, the operator is competent, and you are not a psychopath skilled at defeating polygraph interrogations.


That said, it is well to remember that the reliability of the polygraph to consistently distinguish between truth and falsehood is not universally accepted.


© 2017 Force Science Institute Ltd.