Key to Strength May Not Be Muscles

Science is beginning to mount significant evidence to demonstrate what weightlifters have known for ages: strength is about more than muscles. A recently published study suggests that neural adaptations, not increases in muscular size, are the greatest factor in how the human body gains strength.

If you aren’t integrating resistance training into your exercise regimen, then you are missing out on countless benefits to your physical and even mental health. Recent research has demonstrated that you don’t necessarily have to load bar-bending amounts of weight to increase lean muscle mass and improve your body composition, more volume with lighter weight can be just as effective. But strength gains still appear to be directly associated with heavier loads and researchers from Oklahoma State University have begun unraveling the mechanisms as to why this occurs. In a randomized parallel group study, researchers examined the influence of resistance training loads on the activation of motor neurons, nerve cells within the spinal cord that facilitate muscular contraction.

What they discovered is that motor neural activation increased progressively with increased loads and that study participants who completed low volume, but high-load training sessions experienced the greatest increase in voluntary activation (the proportion of maximal muscular contraction) over the course of the three-week trial period. Without any increases in muscular size, high-load participants experienced a 2.35 percent increase in voluntary activation in only three weeks, while the low-load participants did not experience any measurable improvement.

While not a groundbreaking conclusion (exercise scientists and regular strength trainers have long believed that high-load training is more efficient for inducing gains in strength), we now have some empirical data to help us understand why new weightlifters often experience dramatic increases in strength without significant gains in muscle mass and how heavier loads induce greater improvements in strength. The secret isn’t in the muscles, but in the involvement of our nervous system and how heavier loads force our motor neurons to work closer to their maximal capacity to make those muscles contract. If you are simply looking to increase muscular size or concerned about the added risk that comes with heavy weights, high-volume and low-load resistance training can still help you reach your goals. But for you weightlifters out there: there is no replacement for heavy weights when it comes to developing power and strength. No matter what your goals, don’t forget to toss your bottle of Deep Blue® Rub in your gym bag and get to work.