I always love it when someone new to the weight room says they don't want to "get too bulky," or when a high school coach tells me he needs a freshman to "get big this spring." The conversations which usually ensue after these statements usually indicate a misconception as to the process of adaptation which normally occurs at the onset of beginning some kind of strength training program or formal Strength and Conditioning plan. It's understandable to want these outcomes when starting a program, but when we look at first starting out in a training program we have to grasp a few things about strength adaptations.
Now, the original comments can be assigned to any number of scenarios, though I think most of us can easily assign who may utter either of those goals regarding size. However, for either of these statements, they lead to assuming the path adaptation takes in the weight room is immediately physiological. In fact, it may happen in reverse of what you may think.
To understand how adaptation works, we need to have a working understanding of how muscles contract and create movement.
Everything we do starts at the brain.
The brain sends signals through motor neurons to a point called a neuromuscular junction, or where a nerve ending meets a group of muscle fibers. The chemicals used in the transmission of the signal trigger a reaction in the muscle fiber which causes it to contract. The contracting muscle fibers then shorten (or lengthen) to create movement.
When we look at the muscle fibers contracting and at the neuromuscular junction, I want you to think of it like a lightbulb. If you're reading this article, you're probably old enough to remember the old 100W candescent light bulbs which were used predominantly in households. These eventually got traded out for 60W lightbulbs, then 40W light bulbs, and now into the newer LED lightbulbs which take up who knows how small a wattage. The point being, initial training adaptations are much like the evolution of a light bulb.
To get a muscle to contract, your nerves have to send enough signal to stimulate a contraction from the muscle fibers. Especially in untrained individuals who have little to no exposure to strength training, this often lends itself to requiring a lot of stimulation. And when we look at the muscle tissue or muscle group as whole, untrained individuals may not coordinate those muscles firing. Think of it like flipping on a switch to those old light bulbs and one of them flickering or being delayed for a second before coming on.
So when we look at the first adaptation new trainees are going to have, the first process isn't necessarily increased size or strength, it's increased efficiency and reactivity of the neuromuscular junction. It's like changing out the 100W lightbulb for a 60W.
This is what we consider to be increased neuromuscular coordination, or the sequencing of muscle contractions.
The beauty of this initial adaptation, is how brief a time it takes to kickstart and see reasonable changes in strength and efficiency. You may see a new trainee make large initial gains in strength without gaining size due to simply having an increased efficiency in recruiting muscle fibers to do the job. It doesn't necessarily mean the muscle fibers get larger, but they do need less energy to be recruited to do the job they were asked to do.
Once we have adapted at a neural level, we start to see greater increases in soft tissue durability and strength. This includes, muscle, tendon, ligament, and fascial structures throughout the body. This often happens with minimal gains in size, and may even be a period where some individuals see a drop in fat mass (or overall weight loss). The big thing, however, is to not rush through this phase. Because when we look at moving into physiological and cellular adaptations, we need to remember how pushing soft tissue past it's load tolerance can lead to injury. Many people like to rush straight into maximal intensity lifting without taking time to let soft tissue get used to incrementally heavier loads.
After a new trainee has adapted at the neurological and soft tissue level, you'll start to see greater physiological changes. Now, these changes have a ton of influencing factors on them such as age, sex, phase of puberty (for those beginning between 10-15 years old), nutrition, and frequency of training. All of these things will impact the adaptation for size and strength. This is where most time ends up being spent later in one's training age, but it most be understood how the first year or two is going to lean heavily on the neurological and soft tissue adaptations in new trainees.
So if you've got new trainees, or maybe you are the "new trainee," stepping into the weight room this year I would implore you to take the following few pieces of advice:
Spend time mastering the movement basics. Squat, hinge, press, and pull until you get so bored of them you don't want to show up to the gym anymore. Then show up for a few more months. This will allow your nervous system and those neuromuscular junctions to adapt and become more efficient.
Spend a lot of time under tension. Do movements in a wide variety of tempos. Especially eccentric (slow lowering) tempos and isometric tempos, because those stressors trigger soft tissue repair and aid in building more resilient soft tissue structures.
Be patient. We all want to rush the process of getting stronger, moving on to heavier weights, or getting to do fancy exercises. It's understandable. But the more shortcuts means more opportunities for mistakes, and mistakes in the weight room can lead to setbacks which may effect more than just the gym.
With this in mind, hopefully we can build a more robust strength, developed with long term success in mind. The more we understand this adaptation process, the better we can be successful on the court, field, or life.