Sleep Deprivation and Physical Performance: What Every First Responder Needs to Know
Nobody told me when I started this job that sleep deprivation was part of the job description.
Not in those words. But after your first year working 24-on/48-off, running calls through the night, catching an hour here and there, reporting back before your body finished recovering from the last shift, you understand it. This isn't a temporary inconvenience. It's the permanent condition of the work.
What took me longer to understand was what chronic sleep deprivation was actually doing to my body. Not just the fatigue, everyone knows about the fatigue. The deeper stuff: what it was doing to my hormones, my physical capacity, my recovery between shifts, and the long-term cost of running at a deficit for years.
After 21 years, I've learned what helps and what doesn't. More importantly, I've learned that most of what the wellness industry says about sleep is written for people who can choose when they sleep. For first responders, military personnel, and anyone whose schedule is set by someone else's emergency, the conversation has to start somewhere different.
What Sleep Deprivation Actually Does to Physical Performance
This isn't about feeling tired. Sleep deprivation produces measurable, documented physiological changes that directly impair physical performance. Understanding the mechanism matters because it tells you what to target.
Glycogen replenishment is impaired. During sleep, your body restores muscle glycogen, the fuel that powers anaerobic and high-intensity aerobic efforts. Without adequate sleep, that restoration is incomplete. You show up to the next shift or the next training session with partially depleted fuel stores, regardless of what you ate.
Testosterone drops. Cortisol rises. Sleep is when the majority of daily testosterone production occurs. Reduce the sleep, reduce the output. Meanwhile, sleep deprivation keeps cortisol, the stress hormone, chronically elevated. The relationship between cortisol and testosterone is oppositional: when one goes up, the other comes down. After years of shift work, this isn't a short-term fluctuation. It becomes a sustained hormonal baseline that affects energy, recovery rate, muscle retention, and overall physical capacity.
Protein synthesis slows. Muscle repair happens primarily during sleep. Disrupted sleep means the physical damage from training or an active shift is repaired more slowly and less completely. That's why first responders often feel like they're never fully recovered because structurally, they often aren't.
Reaction time and coordination degrade. Research is consistent on this point: after 20 hours of sustained wakefulness, reaction time deteriorates to a degree comparable to legal impairment. Physical coordination such as balance, movement precision, motor control, follows the same curve. For someone operating in a physically demanding environment, that degradation has direct safety implications.
Immune function drops. Sleep is a core component of immune regulation. Chronically sleep-deprived first responders are more susceptible to illness, slower to recover from minor injuries, and more vulnerable to the inflammatory conditions that accumulate over a long career in high-demand occupational roles.
The takeaway: sleep deprivation isn't just fatigue. It's a systemic physiological state that affects fuel availability, hormone balance, tissue repair, coordination, and immune function all at once.
What You Can Control
You can't always control when you sleep. You can control the quality of sleep when it happens, what you put in your body before and after shifts, and how you support the systems sleep deprivation most directly attacks.
That's where supplementation is actually useful for this population, not as a replacement for sleep, but as a targeted intervention for the specific physiological gaps shift work creates.
The Recovery Stack for Sleep-Deprived Athletes
Creatine — For Fuel and Cognitive Resilience
Creatine does two things that are directly relevant to sleep-deprived physical performance.
First, it increases the phosphocreatine stores your muscles draw on for fast, explosive efforts. When glycogen replenishment is impaired by disrupted sleep, having well-saturated creatine stores provides an additional fast-energy substrate for high-intensity output. It doesn't replace glycogen, but it meaningfully reduces the performance cost of running partially depleted.
Second, and this is the piece most people miss, creatine supports cognitive performance under sleep deprivation. Research published in Sleep found that creatine supplementation improved mood, cognitive function, and reaction time in subjects after 24 hours of sleep deprivation. The brain uses creatine phosphate as a fast energy source during high-demand cognitive tasks. When the brain is sleep-deprived and its energy metabolism is already stressed, well-saturated creatine stores reduce how much that deficit costs you.
For the full breakdown of creatine's specific benefits for first responders, read Creatine for Firefighters: What the Research Actually Says.
Daily dose: 3–5g, with any meal. Consistency matters more than timing. Saturation builds over weeks and benefits persist as long as you keep taking it.
Our Creatine Hydration Powder pairs creatine with electrolytes — relevant here because sleep deprivation impairs fluid regulation, and dehydration compounds both physical and cognitive impairment.
Magnesium Glycinate — For Sleep Quality in the Windows You Have
You may not be able to get eight hours. But the quality of the sleep you do get is something you can influence.
Magnesium glycinate is one of the most evidence-based supplements for improving sleep quality, specifically sleep depth and restorative value, not just the ability to fall asleep. It works by supporting the GABA pathways that promote sleep onset and slow-wave sleep, which is the phase most critical for physical recovery and hormonal restoration.
Magnesium also plays a direct role in muscle function and recovery, and it's one of the most commonly depleted minerals in people with high physical output and chronic stress. Most shift workers are running low and don't know it.
Take 200–400mg of magnesium glycinate 30–60 minutes before your sleep window, regardless of what time that is. The glycinate form is gentler on the digestive system than magnesium oxide and is absorbed more efficiently.
Beetroot Capsules — For Cardiovascular Efficiency When You're Running Low
Sleep deprivation impairs cardiovascular efficiency, your heart rate at a given workload is higher when you're sleep-deprived, and your body uses more oxygen to do the same amount of work. Beetroot capsules directly address this by supporting nitric oxide production, which widens blood vessels and improves oxygen delivery to working muscles.
For a first responder arriving at a high-intensity call after a poor sleep night, having better cardiovascular efficiency in the first minutes of maximal effort is meaningful. Beetroot doesn't overcome sleep deprivation, but it partially offsets one of its most direct physiological costs.
Take our Beetroot Capsules 30–60 minutes before a shift for the best effect. On days when you're most depleted, the cardiovascular support matters most.
Hormonal Support — For the Long-Term Toll
Short-term sleep deprivation is a performance problem. Chronic shift-work sleep deprivation over a career is a hormonal problem.
The sustained cortisol elevation and testosterone suppression that come with years of irregular sleep don't resolve with one good night's rest. They become a baseline. Men in high-demand occupational roles consistently show lower testosterone levels than age-matched peers in standard schedule jobs, and the gap grows with years of service.
Supporting hormonal health for first responders means addressing both sides of the equation: reducing the cortisol load where possible and supporting the natural testosterone production that shift work chronically suppresses. Ashwagandha has the strongest research base for both, cortisol reduction and testosterone support in men under sustained stress. Tongkat Ali and zinc support the hormonal production side.
Our Men's Vitality formula addresses this specifically, not as a testosterone booster for the gym, but as hormonal and stress support for men whose occupational demands have been working against their hormonal baseline for years.
The Bottom Line
Sleep deprivation is occupational for first responders. It's not a problem to solve — it's a condition to manage. The question isn't how to eliminate its effects. It's how to reduce the margin it costs you, shift after shift, year after year.
The right nutrition and supplementation strategy closes part of that margin. It won't make a 36-hour shift feel like eight hours of rest. But it can mean the difference between showing up depleted and showing up ready, and over a career, that difference accumulates into something that matters.
Everyone who comes in for their shift should get to go home at the end of it. Taking care of your body is part of how that happens.
J. Bourland is the founder of Valor BioLabs and a 21-year firefighter and Fire Captain. Valor BioLabs makes precision supplements for first responders and serious athletes who need real-world performance.