Why Jessica Biel and Neuromuscular Efficiency Mean Females Should Lift Really Heavy Weights

Why Jessica Biel and Neuromuscular Efficiency Mean Females Should Lift Really Heavy Weights
Written by: Coach Slater

A couple weeks ago, we published the following on Facebook:


“Your 5RM is typically in the ballpark of 85% of your 1RM, but often times higher for beginner/intermediate lifters and female athletes.

In general, the more neurologically efficient you are, the fewer reps you can do with a given percentage of your 1RM. Men are typically more efficient at this than women, so they may only be able to get 2 or 3 reps at 85% while some women may be able to get 15 reps.

That’s why we write “find a heavy ###” for our Life programming, because percentages don’t always tell the full story behind your training history and true ability to generate maximum power. You may surprise yourself if you don’t limit yourself to a certain percentage.”

So, today, I thought I’d try to quickly explain the neuromuscular difference between males and females so you can better know yourself… and maybe secretly drive home the fact that females NEED to strength train by striving to pick up seriously heavy weight.

Women can perform more reps with a higher percentage of their 1RM for five than men can. Most women can do five reps of a certain lift within 5 to 15 pounds of their one rep max. A woman with a 225lb deadlift, can normally do 210lb for five reps. That’s around 95%. However, men usually have a 5RM somewhere within 85-87% of their 1RM. It’s not men’s fault that this is the case. It’s just a difference in their nervous system’s ability to apply force.

Athletic performance is greatly dependent on power – the ability to display strength quickly. This is basically the definition of neuromuscular efficiency. So, a 1RM is not only a test of your muscular ability, but also your neurological ability. This is your capacity to exhibit maximal force and how efficient you are at it. This efficiency decreases with age, unfortunately, but it also varies due to your genes and sex. This explains the difference between average and elite athletes, between younger and older athletes, and between male and female athletes.

Quick biology lesson: A motor unit consists of one motor neuron and all of the muscle fibers it stimulates. All muscles consist of a number of motor units. And, the fibers belonging to a motor unit are dispersed amongst fibers of other units. So, the activation of motor units results in muscle fibers activating. Motor unit recruitment is therefore a measure of how many motor neurons are activated in a particular muscle. Lesson over.

If men can recruit 98% of their motor units for a 1RM, women may only able to recruit maybe 90%, maybe 85%, or maybe less. So, a 1RM for a male and a female are two different neuromuscular events. Light sets of five for a female may not be heavy enough to drive the stress / recovery / adaptation cycle the same way it does for males. So, when we tell you to go heavy and not limit yourself to a certain percentage, there’s real science behind that statement. Maybe you really shouldn’t limit yourself to a percentage – depending on your training experience. Strive for a big number, even if that number feels strangely close to (or even above) your old 1RM.

Those heavy weights equate to the body that many women strive for… that seen on Jessica Biel or Jamie Eason… hell, even Kate Upton pushes a 500lb sled for her training. And to get their muscle definition, you have to lift heavy. Strength training is the ultimate way to improve body composition, far outweighing the benefits of typical “cardio” or long, slow, distance running, because muscles have a higher energy expenditure. Plus, the act of strength training has a greater effect on your body’s thermogenesis, how much heat it produces, thus how many calories it burns to stay cool. So, you have to challenge yourself every time you step in the gym. Some days, don’t worry too much about the percentage… just go heavy and flirt with that nervousness that comes with “big numbers”. It’s maybe more important for you to lift heavy weights than it is for men. Plus, you might be able to hit that 95% for five reps today.

Why Females Lift Less Efficiently”, Lascek, J.

Neuromuscular efficiency of the rectus abdominis differs with gender and sport practice”, David P, Mora I, Pérot C.

Monitoring strength training: Neuromuscular and hormonal profile”, Carmelo B, Roberto C, Robert B, Serge V, Atko V.

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