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The mind is the strongest muscle

Tap in to the hidden strength gains available from your nervous system

Photo by: Getty Images

“Whether you think you can or think you can’t, you’re probably right.”

This quote, attributed to Henry Ford, about sums up the attitude that many triathletes have when it comes to mental strength.  And yet this is not the type of mental strength that I want to talk about here. The mind (or really the entire nervous system), is indeed the most significant determiner of muscular strength, but not simply because of the power of self-belief. It can create real strength as well. How is this possible?

For a long time, the variable that was considered to be of prime importance to determining the strength of a muscle was the cross-sectional area of that muscle. Basically, the bigger your muscles, the more force you can generate. However, this model did not explain some observed phenomenon. For example, it could not explain how Olympic weightlifters were able to increase the amount of weight that they could lift, year after year. These athletes are limited by weight classes, and they are already very lean, meaning that they could not simply lose fat and add muscle if they wanted to lift more. Something else had to be happening during their training to allow them to increase their strength.

Related: What is muscular activiation?

It turns out that what happens is that the nervous system adapts to the stress of lifting heavy training loads with deep, internal modifications to the way that it interacts with the muscles it is responsible for activating. The signals that flow to these muscles, and the muscles’ response to these signals become more efficient – with the groups of fibres within the muscles acting in a more coordinated and unified manner. This leads to increased ability to produce external force at the joint, something we see as the ability to move larger weights. This response to lifting increased loads is highly transferrable, meaning that if you develop this ability in your quads from doing squats, it will help you whenever your quads contract, not just when they contract doing the squat motion.


You should do some strength training in motions that very closely resemble the movements involved in your primary sports. Photo: Getty Images

The other way that the nervous system adapts to the stress of lifting heavy weights is by coordinating the action of all the muscles that are working together to make them more efficient. Since you are always using many muscles together, no matter what movement you are doing, coordinating these actions can make a big difference to the final external force you can produce. This efficiency can mean better sharing of loads by many muscles, better coordination of the timing of the action of several muscles or more efficient use of stabilizing muscles to allow the primary muscles to apply more force. These types of adaptations are more specific to a given motion or movement pattern, meaning that, for example, strength developed this way through heavy biceps curls will be less transferrable to the swim stroke than if that same strength was developed by doing lat pull-downs, as the pull-down motion is more similar to the swim stroke than a biceps curl motion.

As a triathlete, there are a few main messages that I would take away from all of this. The first is that you don’t need to add on layers of muscle in order to get stronger – good news for triathletes who don’t want to carry around extra weight. The second is that getting stronger by lifting weights will pay off with more efficiency of movement when you do your primary sports. Who doesn’t like doing more with less work? The third is that you should do some strength training in motions that very closely resemble the movements involved in your primary sports. This might mean running up- or downhill, low-cadence, uphill seated cycling in a heavy gear or swimming short distances with paddles and drag suits or parachutes. Put this all together and you realize that there is more to be gained from strength work than just pure muscle mass. So, add some strength work to your training routine and get your mind (and nerves) working for you.


Bompa, Tudor O and Carlo Buzzichelli. Periodization training for sports 4th Ed. Human Kinetics, 2015.

Darian Silk is a triathlon coach and Clinical Exercise Physiologist based in Toronto.  Read more about Darian here or email him at darian@teamatomica.com.  You can also check out his TrainingPeaks profile here.