When it comes to building our exercise handbags—the essentials we carry with us for health, strength, and longevity—strength training may be the most important tool of all.
At its core, strength training (or resistance training) simply means making your muscles contract against an external resistance. That could be dumbbells, kettlebells, resistance bands, cables, or even your own body weight. The goal? To improve strength, endurance, and muscle size.
But what actually happens inside our bodies when we strength train? Let’s break it down.
How Strength Training Changes Our Bodies
1. Neural AdaptationsIn the beginning, strength improvements aren’t about bigger muscles—they’re about smarter communication. When we start lifting, our nervous system gets better at recruiting motor units (the bundles of muscle fibers activated by a single motor neuron). Your body literally learns how to “talk” to your muscles more efficiently.
2. Muscle HypertrophyAs we lift heavy resistance, tiny micro-tears form in our muscles. This isn’t forever damage—it’s the trigger for growth. During recovery, our bodies repair and rebuild those fibers, making them stronger and more resilient. Exercise is just the stimulus; growth actually happens during the recovery.
Depending on how we train, we can emphasize:
Strength & Power: lifting heavy loads for fewer reps with velocity changes (1-5 reps typically)
Endurance: lifting lighter loads for more reps (12+ reps)
Hypertrophy: somewhere in between the two (6-12 reps)
The Benefits of Strength Training
Strength training doesn’t just help us build muscle, it completely transforms our health and physiology. Some of the biggest benefits include:
Stronger bones (improved bone mineral density, BMD): Protects against osteoporosis, especially important for women.
Fights against age-related muscle loss (sarcopenia)
Improved metabolism: Muscle tissue is metabolically active, helping us burn more energy, in addition to helping us utilize glucose more efficiently.
Reduced disease risk: Lowers chances of cardiovascular disease, diabetes, and even some cancers.
Better balance & posture: Key for preventing falls and injuries.
Mental health & cognition: Supports brain health, mood, and sleep, especially as we age.
Reduced pain: Strengthening muscles protects joints and reduces chronic pain.
Why Strength Training Matters at Every Age
Adolescents: Gives us a strong foundation! Helps us build up to 40% of bone mass during puberty, improve movement skills, and reduce sports injuries.
20s–40s: Maintain bone density, build lean muscle, support reproductive health, and improve recovery.
Perimenopause & Menopause: Counter bone and muscle loss, manage weight, and even improve hot flashes, mood, and sleep.
50+: Preserve strength, reduce fall risk, prevent chronic disease, protect the pelvic floor, and fight cognitive decline.
What Happens If We Don’t Strength Train
Without resistance training, we have an increased chance of:
Osteopenia & Osteoporosis: Weak bones and fragile bones, higher fracture risk.
Sarcopenia: Muscle loss, leading to falls, frailty, and loss of independence.
Metabolic decline: Higher risk of diabetes, cardiovascular disease, and weight gain.
The Basics: How Much Strength Training Do We Need?
3–4 sessions per week is ideal.
1 upper, 1 lower, 1 full-body
2 upper, 2 lower
3 full-body sessions
2–4 sets per exercise
With enough weight to reach fatigue
Key principle: Whatever weight you’re lifting, make sure you reach muscular failure! Muscular failure occurs when your pace starts to slow, your form feels like it is about to falter, or you can no longer move the weight through the full range of motion.
Strength Training Styles: What Counts?
Traditional weights: squats, lunges, deadlifts, presses, curls
Bands, cables, kettlebells, or bodyweight
Barre, Pilates, sculpt classes: Light weights, high reps—these can build endurance and mitochondrial capacity, but won’t build significant strength unless taken to muscular fatigue.
Rule of thumb: To get stronger, your muscles need to reach fatigue before your form breaks down.
The Power of Variation
Our bodies adapt to repeated stress. To keep improving, we need:
Progressive overload: gradually increasing resistance or reps
Variability: mixing heavy/low rep with lighter/high rep. Basically, it is totally okay to enjoy pilates, yoga sculpt, and at-home strength training! As a matter of fact, it is good for you!
Specificity: training for what you want to achieve (if you want to lift heavy boxes, you need to train heavy!)
The golden rule? Muscular fatigue is the key that unlocks strength… no matter the style!
Final Takeaway
If our exercise handbag had only one non-negotiable essential, strength training would be it. It builds bones, protects muscles, fuels metabolism, sharpens the mind, and helps us move through every stage of life with power and confidence.
In health & happiness,
Kelsy