The 40% Rule

Navy SEALs pushing past psychological limits.

The Navy SEALs have what they refer to as the 40% rule: when your mind is telling you you’ve reached your breaking point, you’re really only 40 percent there. Much of their training is centered around breaking down psychological barriers. Performing highly skill-intensive tasks while sleep deprived, pushing their physical boundaries after having eaten almost nothing for days, tempting hypothermia by diving into rough, frigid waters . . . To accomplish amazing things, one must consistently place one’s hands firmly against barriers, dig down deep, and climb over them.

As a health and exercise scientist, I have spent much of my life researching the limits of human performance and finding ways to help elite athletes push their way past them. The greatest athletes I have worked with aren’t necessarily the most inherently talented, they are the ones who accept that continued progression requires progressively harder work. They become comfortable with being uncomfortable. This principle of pushing past barriers is the very foundation of exercise science. The principle of progressive overload asserts that you must progressively increase the demands placed on your musculoskeletal system to continually force gains in size, strength, and endurance. Your body does not miraculously improve because you want it to, it does so as a response to increasingly higher demands. Do the same thing every day, at low intensity, and you are accomplishing little but telling your body that the status quo is fine. If you have made consistent exercise a part of your lifestyle, but aren’t seeing progress, there is no easy way to put it: you simply aren’t working hard enough.

I’m never going to dissuade someone from any physical activity. As recently published research has shown, the singular act of regular physical activity, as moderate as walking for 30 minutes three times per week, results in some amazing adaptations. Those who regularly walk exhibit biological age at the cellular level, measured by the length of their telomeres, of up to 8 years younger than those who are sedentary. But, I don’t know that I’ve ever met a single individual who regularly exercises with the goal in mind of not progressing, and walking on the treadmill at low intensity or doing the same basic resistance training circuit with the same loads, day-in and day-out, is a direct signal to your body that staying the same is OK. Increase the load, the volume, the training frequency, decrease rest times; increase the demands on your body past anything it has ever experienced and it will respond by improving so that it can handle even greater stress next time.

I’m not suggesting you schedule your next training session in a sleep-deprived state like a Navy SEAL would or throw extra plates on the bar until it bends, but if you are running three miles per day, three days a week, at a 10-minute per mile pace and are frustrated that your 5K race time isn’t improving, hit that speed button up a few notches next time. And then a little more the time after. Yep, the increased pace will suck, but it will be worth it at your next race. If your weekly routine includes squatting 135 lbs. for four sets of eight reps with 2 minutes of rest between sets, up the ante by increasing the load, adding an extra set, or decreasing the rest time. Your knees will shake, your mind will tell you that there is no way you can get another rep, but you will and next week you’ll handle the increased demands and ask for more.

The human body is the greatest machine ever created. Does your car miraculously have more horsepower the day after it struggled to get up a hill? After slipping and sliding to gain traction in the snow, does it respond by suddenly developing all-wheel-drive? Your body does; if you place increasingly higher demands on it, fill it with quality fuel, and give it time to recover. You are capable of far more than you believe, and pushing the limits of your own 40% are required to stimulate change. Before every workout, remind yourself that you are just a little bit stronger and better conditioned than last time, and that to make progress you’ll have to push yourself just a little bit further, and you will.

Dr. Damian Rodriguez is the health and exercise scientist for doTERRA International, LLC.He holds a doctorate in health science, a master’s degree in exercise physiology, and countless professional certifications. He has spent most of his life researching nutrition, exercise, and the lifestyle behaviors associated with optimal health. Along with his passion for health, as someone who lives with Asperger’s Syndrome, he is also involved in bringing awareness to autism spectrum disorders. There are varying opinions about many health and fitness topics. His opinions are his own and not necessarily that of doTERRA International, LLC. Consult your healthcare provider before making any changes to diet and exercise.