Lifting weights is part of a complete and balanced exercise regimen, just like fruits and veggies are part of a well-rounded meal. But this one piece of your fitness puzzle is doing a lot more for your body than just building your muscle strength.
When you start out with a weight training program, it’s easy to get really excited about getting strong and toned…but then you may feel like you aren’t seeing the results you’ve been hoping for.
There is a reason for this, and it has nothing to do with how hard you’re working. As it turns out, during the first few weeks of weight training, your body is actually strengthening your nervous system.
New research (1) reveals what goes on in your body during the beginning of a weight training regimen.
Brains Before Braun
Any movement in your body is dictated by your brain, and your brain does this in different ways. There are actually two major neural pathways that lead from your brain down into your spinal cord: the corticospinal tract (CST) and the reticulospinal tract (RST).
These pathways carry commands from the brain’s motor cortex, where muscle contractions are controlled, into your spine and then onto your muscles.
The CST is “newer” in terms of evolution and more refined. It controls things that involve fine motor skills, like grasping objects.
Your RST handles a more broad range of motor skills, specifically your posture.
Scientists have long believed that if those commands along these pathways could happen more quickly and have more “oomph” behind them, muscles would contract and function with more strength.
What they didn’t know was how the nervous system changed to make this happen.
Check Out These Adorable Muscle Heads
To find out what was going on and how your body changes, researchers at the Institute of Neuroscience at Newcastle University in England trained two macaque monkeys to lift weights.
Yup… you read that correctly. Monkeys lifting weights! These particular monkeys were chosen because their CST and RST function in nearly the same way as a human.
The monkeys spent 12 weeks pulling a weighted handle using only one arm. Essentially, they were doing one-armed pull ups while the researchers measured which nerves were activated and how much.
They performed these measurements before, during and after each exercise session.
The amount of resistance, or weight, was increased until the monkeys could complete a workout equivalent to a human doing 50 one-armed pull-ups.
It’s “All in Your Head”
Up until now, many scientists believed the CST had more to do with building strength. However, this new study showed that isn’t necessarily the case.
It was actually changes in the nerves of the RST tract that were strengthened when the monkeys lifted their weights.
By strengthening the nerves in the RST tract, messages from the brain were able to get to the muscles more quickly and with more power, resulting in what we perceive as feeling and being stronger.
Dr. Baker, co-author of the study with Isabel Glover, says (2) their findings show “strength isn’t just about muscle mass. You get stronger because the neural input to your muscles increases.”
Both researchers recognize this as a small study performed with monkeys, however, that shouldn’t be a deterrent.
The results show a lot of promise as more information is gathered. “Initial gains are all about strengthening the reticulospinal tract. Only later do the muscles actually start to grow,” explains (2) Dr. Baker.
Even More Going on Behind the Scenes
Because strengthening the nerves in your spine it isn’t cool enough on its own, there’s even more going on behind the scenes when you start lifting weights!
Strong nerves, build strong muscles, but they also build strong bones (4). That’s right, it’s not just calcium that’s good for your bones…it’s weight lifting.
Studies have shown adding strength training to your workouts not only slows bone loss, but can even help your body strengthen what’s already there.
On average, we lose 1% of our bone mass each year after age 40. This leads to fragile bones, a higher risk of fracture, and osteoporosis.
We know osteoporosis isn’t something you probably think about, but it can’t hurt to be aware. An estimated 8 million women and 2 million men in the US have osteoporosis, those aren’t small numbers.
Experts report that more than two million bone fractures per year are due to osteoporosis! These fractures can keep you from living your best life, but you can fight it.
How Does Weight Lifting Help?
Activities, like weight lifting, that place stress on your bones can kick the bone-forming cells in your body into high gear. The stress results from the pushing and pulling on your bones that happens during strength training. As a result, you get stronger, denser bones.
You can also get these benefits from aerobic exercise which requires you to bear your own weight, like walking or running, but strength training really does the trick.
When you are performing weight lifting exercises, you are moving and using the bones in your hips, spine and wrists, which are more susceptible to fracture. By placing that stress on them in a controlled fashion, you are building them up, making it less likely you’ll suffer those injuries.
Even if you don’t have a weight set at home, you can still get these benefits. Simple resistance training will help build up your bones too. By focusing on exerting force and balance, you are building your strength and stability.
We know when you’re lifting weights, you’re also looking in the mirror for results. Remember that it’s completely normal to not see those results right away, but it doesn’t mean your efforts are in vain.
You may not be seeing it on the outside just yet, but your body is working and building a stronger you on the inside every time you hit the weights.
(1) https://www.jneurosci.org/content/40/30/5820 Cortical, Corticospinal, and Reticulospinal Contributions to Strength Training: Isabel S. Glover and Stuart N. Baker; 2020
(2) https://www.sciencedaily.com/releases/2020/06/200629132104.htm Lifting weights makes your nervous system stronger too. Society for Neuroscience; 2020
(3) https://www.nytimes.com/2020/07/01/well/move/how-we-get-stronger.html#:~:text=Weight%20training%20prompts%20changes%20in,to%20get%20bigger%20and%20stronger.&text=When%20we%20start%20to%20lift,cellular%20effects%20of%20resistance%20training. How We Get Stronger: Gretchen Reynolds; 2020
(4) https://www.health.harvard.edu/staying-healthy/strength-training-builds-more-than-muscles Strength training build more than muscle: Harvard Health Publishing;