Bones and Muscles
I have to apologize for something. I love a good ramble. I see the world, and every philosophy, concept and idea within it, as being very grey and nuanced. Nothing can be seen as right and nothing can be seen as wrong (bar some very obvious current political situations and conflicts here and around the world).
No black and whites, but that doesn't mean the earth is flat. We can take certain baseline facts as the foundation for any discussion.
So when I write about training and movement I sometimes write in very abstract ways, assuming that everyone knows the baseline facts.
Apologies. After a recent chat with a friend who has been training all their life, but is not a professional in the industry, it hit me how big the gap is between using your body and understanding the mechanisms that control it. The baseline facts.
Preamble aside. I'm going to start a little series on how the body works, the systems within it, and the effect of training on each one.
First up: the musculoskeletal system. Bones and muscles.
The Skeleton
The scaffolding to the whole thing. Keeps us upright, gives us a bit of shape, protects our organs, produces blood cells, and stores minerals our body pulls from when it needs them. No bones, no human. Simple.
What we don't realise though, bone is living tissue, and living tissue like anything else can be trained. It responds to stress. When you load it through weight bearing, resistance training, and high impact activity, it gets denser and stronger. This process of loading and stressing signals cells called osteoblasts to lay down new bone tissue.
When you don't load it, a different cell gets the signal that bones are fair game for energy and starts to break them down. These are called osteoclasts.
That is why Uptown Movement training protocols are geared towards lifting heavier weights and preparing the body for jumping. High loads and impacts build badass bones.
For people assigned female at birth, this matters more than most people realise. Bone density peaks in your early 30s and declines gradually after that, accelerating around menopause. Resistance training is one of the most evidence-backed ways to slow, and in some cases reverse, that decline. Which brings up an interesting debate around why this is, but I promised no rambling. Hint: it's not just biological. The patriarchy f**ked your bones dude.
Muscles
Muscles are what move and protect your bones. Unlike the milk ads of our youth, your bones are not stacked upon each other. Your thigh bone doesn't rest on your shin bone. Instead, bones float in space and your muscles maintain the tension that allows this to happen. This is known as the tensegrity theory. The better your muscles function, the better your skeleton functions.
Outside of being the body's movement engine, muscles are a metabolic powerhouse. More muscle means a higher resting metabolism, better blood sugar regulation, and more resilience as you age.
Muscles work by contracting and relaxing in what is known as the sliding filament theory. Tiny protein structures called actin and myosin work together. When a nerve signal arrives, myosin heads grab onto actin and pull, creating the force we call a muscle contraction.
These signals are sent with every movement, picking up a laundry bag, walking up stairs. Your actin and myosin are having a party. The harder the signal, the harder they work.
When given a stimulus to do heavier or harder work, they need to invite more filaments to the party. In order to do that, they need a bigger room, so we build bigger muscles.
If the stimulus is too big, everyone goes home and there's no party at all. That's why progressive training is so important.
There are three types of muscle fibre:
Type I — Slow twitch fibres Built for endurance and long duration work. Think marathon runners.
Type II — Fast twitch fibres Built for strength and speed. Think sprinters and jumpers.
Most of us normal humans have a roughly even split of all three. The genetic freaks that make it to the top level of their sport tend to be predisposed towards one fibre type over another.
On that note, we all have a genetic cap on the amount of muscle we can build. So never compare, just train hard and love yourself, my guy.
Different training for different outcomes
Heavy resistance training (lower reps, higher load) Targets fast-twitch fibres and creates the most mechanical stress, building strength and muscle density. This type of training should be introduced after the basics are mastered and you understand what intensity means. Training something for 4 reps when you could do 12 is pointless. Only start introducing low rep work when you know how to push.
Moderate resistance training (higher reps, moderate load) Recruits both fibre types. Drives muscle hypertrophy (growth) and improves muscular endurance. The workhorse of most well-rounded programmes, this is where most of your training time should be spent.
Stretching and mobility work Doesn't directly build muscle or bone, but plays a critical supporting role. Stretching improves the length-tension relationship of muscle fibres, meaning your muscles can generate force across a fuller range of motion. Think of stretching as strength training. Strength at length.
What this looks like at Uptown
We use compound lifts, squats, deadlifts, presses, rows, to load multiple muscle groups and the skeleton simultaneously
We programme across rep ranges intentionally: heavier sets for bone loading and strength, moderate sets for muscle development and endurance
Every session includes mobility and stretching as part of how we keep your muscles functioning well through their full range
We scale every movement to where you are right now, not where you think you should be. Bone and muscle adaptation takes time, and we work with that biology to build for the long term
That's it kids, lesson one on the body done. Next up: fascia and joints.