Why You’re Always Tired — And How Strength Training Can Actually Help
You’re sleeping enough (or at least trying to), eating decently, and maybe even getting your steps in — but you still feel tired all the time. Sound familiar?
For many people, especially women between the ages of 25 and 55, chronic fatigue has become a frustrating norm. The kind of tired that coffee doesn’t fix. The kind that feels more like foggy, unmotivated, and drained than just sleepy. And while rest and recovery are important, the solution isn’t always to do less. Sometimes, it’s about doing something different — like lifting weights.
It might sound counterintuitive: “If I’m already tired, why would I work out?” But strength training isn’t just about building muscle or changing how your body looks. It’s one of the most powerful tools we have to improve energy production at the cellular level, regulate hormones, support better sleep, and even sharpen mental clarity.
This post dives into why your body might be stuck in a cycle of low energy and how resistance training can help you break out of it. With science-backed benefits for both your body and brain, lifting could be the missing piece in your energy equation.
Your Cells Might Be Tired, Too
At the core of your energy system are mitochondria — the tiny, membrane-bound organelles often called the “powerhouses” of your cells. Their main job is to take nutrients from the food you eat — particularly carbohydrates and fats — and convert them into adenosine triphosphate (ATP), which is your body’s primary source of usable energy. Nearly every cell in your body relies on ATP to function, from your brain cells firing during a conversation to your muscles contracting when you walk or lift.
But mitochondria do more than just supply energy. They’re also involved in regulating oxidative stress, controlling inflammation, and even influencing the aging process at a cellular level. When mitochondrial function declines — which can happen with age, inactivity, poor diet, or chronic stress — ATP production drops. The result? Fatigue, sluggishness, and reduced physical and mental performance.
Inner Membrane: Contains proteins involved in the electron transport chain and ATP synthesis.
Outer Membrane: Serves as the boundary between the mitochondrion and the cytoplasm.
Cristae: Folds of the inner membrane that increase surface area for energy production.
Matrix: The innermost compartment containing enzymes for the Krebs cycle.
Mitochondrial DNA: Genetic material unique to mitochondria, essential for their function.
Ribosomes: Sites of protein synthesis within the mitochondrion.
This is where strength training comes in. Regular resistance training has been shown to stimulate mitochondrial biogenesis — the process of creating new mitochondria — as well as improve the efficiency of the ones you already have. A landmark 2017 study published in Cell Metabolism found that after 12 weeks of high-intensity resistance training, older adults experienced significant increases in mitochondrial content and gene expression related to energy metabolism. In fact, their mitochondrial function began to resemble that of much younger individuals.
In practical terms, this means that strength training doesn’t just help you use energy better — it helps you create it more effectively. The more high-functioning mitochondria you have, the more efficiently your cells can turn food into fuel. And with better energy production at the cellular level, you’re more likely to feel focused, resilient, and physically capable throughout the day — not just during workouts, but while doing your job, taking care of your family, or enjoying your downtime.
So when you pick up a weight, you’re not just working your muscles — you’re training your cells to be better energy producers. And over time, that internal shift adds up to more lasting energy, better recovery, and a stronger sense of vitality.
Hormones, Mood & Motivation: The Invisible Drivers of Fatigue
Fatigue isn’t always physical — in many cases, it’s driven by hormonal imbalances and neurological overload.
One of the biggest culprits? Chronic stress. When you’re under prolonged pressure (work, family, emotional strain), your body releases excess cortisol, the main stress hormone. Cortisol is meant to spike in the morning and decline at night — but when it stays elevated for too long, it leads to:
Disrupted sleep and circadian rhythm
Blood sugar instability and cravings
Increased inflammation
Emotional exhaustion and “wired-but-tired” fatigue
Poor recovery from daily stressors
Over time, this creates something called HPA axis dysregulation, where your body stops responding to stress signals properly — leaving you feeling flat, reactive, or chronically drained.
Strength training can help regulate this. Although lifting weights temporarily raises cortisol (which is a normal response to effort), your body becomes more efficient at clearing and balancing it over time. With consistent resistance training, your HPA axis adapts, helping you recover from stress faster and stay more emotionally regulated throughout the day.
But it’s not just about reducing stress hormones — lifting also boosts the “feel-good” chemicals in your brain:
Dopamine: Helps with focus, motivation, and a sense of reward after completing a challenge
Serotonin: Supports emotional balance, sleep, and overall mood stability
Endorphins: Act as natural painkillers and reduce the perception of stress
These neurotransmitters work together to lift your mental energy and combat symptoms of low mood, anxiety, or burnout — especially if your fatigue feels more emotional than physical.
For women, lifting also helps regulate estrogen and testosterone, which naturally decline with age and stress:
Testosterone: Supports muscle growth, bone density, energy, and libido
Estrogen: Helps with mood, neuromuscular coordination, joint health, and cognitive function
Resistance training doesn’t spike these hormones in excess, but it supports your body’s ability to maintain them. It reduces visceral fat (which disrupts hormone balance), increases lean muscle (which supports metabolic health), and stimulates natural hormone production through consistent muscular activation.
So if your energy has been dipping — mentally or physically — strength training may be one of the most powerful ways to rebuild it.
You're not just lifting for your body. You're lifting for your nervous system, your hormones, and your mindset.
Strength Training Supports Better Sleep — Naturally
You might be clocking eight hours in bed, but if you’re not hitting deep, restorative sleep, you’re still going to feel tired. Strength training improves sleep quality, not just duration.
A 2019 review published in Sleep Medicine Reviews found that resistance training improved slow-wave sleep and helped people fall asleep faster. It also helped regulate the body’s circadian rhythm — which influences everything from hormone release to digestion and alertness.
By training your body through lifting, you set the stage for better nighttime recovery — and more energy the next morning.
Daily Life Doesn’t Feel So Draining When You’re Stronger
Lifting isn’t just about what happens in the gym. It changes how you move through everyday life.
When your muscles are undertrained, basic tasks like climbing stairs, carrying groceries, or standing all day demand a lot more from your body. You’re operating closer to your limit just to get through normal routines.
But when you build strength, you increase your reserve — meaning those same tasks require less energy. You’re no longer using 80–90% of your capacity to get through the day. You have more in the tank, which translates to less physical fatigue and more freedom.
It Helps Break the “I’m Tired So I Don’t Move” Cycle
One of the toughest cycles to break is the one where feeling tired leads to inactivity — and inactivity makes you feel even more tired. Over time, that can lead to a kind of inertia that’s hard to shake.
The key? Movement that restores instead of depletes. Moderate strength training does exactly that.
Unlike high-intensity cardio that can spike stress hormones, lifting with rest between sets helps engage your parasympathetic nervous system — the part of your nervous system responsible for calm, recovery, and digestion. Research in Frontiers in Physiology (2020) shows resistance training can shift the body toward a more regulated, grounded state post-workout.
You finish your workout not more wired, but more balanced.
It’s easy to think fatigue means you should rest more — and sometimes, that’s true. But if you’ve been stuck in a loop of low energy for weeks or months, rest alone might not be the answer.
Lifting weights gives your body the stimulation it craves. It improves mitochondrial health, balances your hormones, sharpens your mental clarity, and supports better sleep — all of which feed into the energy you feel day-to-day.
You don’t need to go hard or train every day to see these benefits. Even 2–3 well-structured strength workouts a week can change how you feel.
If you’re tired of being tired, strength training might be the reset button your body has been waiting for.
Hope that helps,
Happy Exercising!
Robyn
References
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