The Epley 1RM Formula
The Epley formula, developed by Boyd Epley in 1985, is a widely used method for estimating your one-rep max (1RM) based on a submaximal lift. This guide explores the formula’s history, its development by Epley, and its unique role in strength training.
Boyd Epley: The Father of Modern Strength Coaching
Boyd Epley, born in 1947 in Pawnee City, Nebraska, revolutionized strength training. As a young athlete, he battled asthma, moving to Phoenix, Arizona, where his father introduced him to weight training in seventh grade. This sparked a lifelong passion, leading to success in weightlifting and pole vaulting. Epley earned scholarships to Phoenix College and the University of Nebraska, where he set a pole vaulting record of 21 feet. A back injury ended his competitive career, but it redirected his focus to coaching, where he began helping athletes in Nebraska’s weight room.
In 1969, at age 22, Epley became the first full-time strength coach at Nebraska, launching the “Husker Power” program. His innovative training methods helped Nebraska’s football team win five national championships and produced numerous All-American athletes. Assistant coach Tom Osborne, seeing the results - stronger, faster players - convinced head coach Bob Devaney to formalize the program, overcoming skepticism that weight training reduced flexibility. In 1978, Epley founded the National Strength and Conditioning Association (NSCA), now a global authority with thousands of members. His contributions earned him induction into the USA Strength and Conditioning Coaches Hall of Fame and the Legends Award from the Collegiate Strength and Conditioning Coaches Association (CSCCa).
The Epley Formula: A Simple Solution
The Epley formula estimates your 1RM using a weight you can lift for multiple reps. It’s expressed as:
1RM = weight × (1 + reps/30)
For example, if you bench press 100 kg for 5 reps, your 1RM is:
1RM = 100 × (1 + 5/30) = 100 × 1.1667 ≈ 116.7 kg
Its simplicity and focus on 2-10 reps make it a go-to for coaches, especially for compound lifts like squats, deadlifts, and bench presses. The formula assumes a linear relationship between reps and strength, which Epley found effective for most athletes in his training programs.
How Epley Developed the Formula
In the early 1980s, Boyd Epley faced a challenge at Nebraska: measuring athletes’ maximum strength without the risks of heavy max lifts. Weight training was controversial then, with many coaches believing it caused stiffness or slowed athletes down. Epley needed a safe, reliable method to demonstrate strength gains. He developed the formula by analyzing submaximal lifts (2-10 reps) performed by his athletes, particularly football players, and correlating these to their maximum potential.
Epley’s process involved testing various weights and rep ranges, observing how athletes performed under controlled conditions. He refined the formula to be simple yet accurate, settling on the factor of 1/30 to approximate the strength drop-off per rep. For example, he might have a linebacker squat 150 kg for 8 reps, estimating a 1RM of approximately 190 kg, then use that to set training loads. Published in his 1985 Boyd Epley Workout poundage chart, the formula gained traction through Epley’s NSCA clinics and coaching network, becoming a staple in strength training.
Epley’s Influence
Boyd Epley’s formula reflects his innovative approach to strength training. His “Husker Power” program not only produced championship-winning athletes but also proved that strength training could enhance speed and agility, challenging outdated myths. Through the NSCA, Epley professionalized strength coaching, creating standards and certifications that shape the field today. His formula remains a cornerstone for safe strength assessment, used by coaches and athletes worldwide. Epley’s mantra, “Your work habits determine your future,” captures the formula’s essence: a systematic, safe way to push your limits.
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