PREMIUM SITREP

Human Performance Optimization | The Performance Enhancers Series

What Actually Improves Physical Performance?

By Christopher Piercecchi, MD

_{This article is for educational purposes only and is not personal medical advice. It does not create a physician-patient relationship. Decisions about your health should be made with a qualified clinician who knows your history.}

Gentlemen, this is the first installment of our premium SITREP series, Human Performance Optimization. Over the next month or so, this first run will focus on performance enhancers — the supplements, powders, hormones, and compounds the marketing world swears will make you stronger, faster, and more powerful. I’ll delve into the research and tell you what works, what doesn’t, and what the evidence actually supports.

This first SITREP will provide an overview of what’s to come.

Why am I focusing on this topic? Because the vast majority of what men hear about performance enhancement is nonsense, misinformation, exaggerated marketing, or unsupported claims being parroted by people who repeat whatever they’ve heard and already want to believe. It’s a minefield for the man who truly wants to optimize his physical performance.

The marketplace includes everything from ordinary nutrition and legitimate supplements to prescription hormones, experimental compounds, and illicit performance-enhancing drugs. These are often discussed in the same online environment and presented as though they’re all reasonable options on the same performance-enhancement continuum. A podcast might move from creatine to testosterone to BPC-157 to growth hormone without adequately distinguishing their differences in evidence, risk, medical legitimacy, or expected effect.

The sheer amount of information hasn’t made it easier for men to decide what’s worth using. It’s often made the decision more confusing because marketing, testimonials, proposed mechanisms, animal research, and actual human performance evidence are routinely mixed together.

This series will sort through that confusion and answer a more useful question:

What actually improves meaningful physical performance, for whom, by how much, under what conditions, and at what cost or risk?

What Counts as Physical Performance?

Before we can answer that question, we must first define what we mean by physical performance. Physical performance isn’t one thing. It includes strength, power, muscular endurance, repeated high-intensity effort, aerobic endurance, muscle growth, recovery, body composition, and the ability to remain alert and tolerate difficult exercise. One thing it doesn’t include is longevity. This series isn’t about lifespan, healthspan, or living better into your later decades. Some of these compounds get discussed constantly in that context, and a few of them may have a legitimate role there, but that’s a separate question I’m not addressing here. The only thing on the table in this series is whether something helps you lift more, run faster, produce more power, or otherwise do more work. If it makes you healthier but not more capable, it doesn’t belong here. These outcomes overlap, but they’re not interchangeable. Strength is the ability to produce force, while power is the ability to produce that force rapidly. Aerobic endurance is the ability to sustain physical output over time and delay fatigue. Repeated high-intensity performance refers to the ability to reproduce hard efforts, whether that means repeated sprints, intervals, cycling attacks, or demanding sets in the gym.

Muscle growth and body composition also need to be considered separately from performance itself. Greater muscle mass may support strength and function, and reducing excess body fat may improve movement and endurance. However, changes in appearance don’t automatically mean that someone performs better. The same is true of recovery. Feeling less sore isn’t necessarily evidence that the body has recovered more quickly. A meaningful recovery benefit should help restore strength, power, endurance, or readiness for the next training session.

Some interventions work through a different route. Caffeine and other stimulants may improve alertness, reduce perceived effort, or allow someone to tolerate a heavier workload. That can produce a legitimate performance benefit, but it’s different from directly increasing muscle strength, aerobic capacity, or the body’s ability to recover.

Throughout this series, every product or intervention will therefore be judged according to the specific outcome it’s supposed to improve.

Raising a hormone, increasing blood flow, changing a biomarker, producing a temporary pump, or making someone feel more energized isn’t enough by itself. The question is whether that change produces a measurable and meaningful improvement in what the person can actually do.

How Will We Decide What Actually Works?

To answer that question, we need to be clear about what counts as evidence. A compound may have a plausible biological mechanism, alter hormone levels, increase blood flow, reduce soreness, or produce a noticeable sensation during a workout. Those findings may be interesting, but they don’t establish that the product meaningfully improves physical performance. Increasing growth hormone doesn’t automatically mean faster healing. Increasing nitric oxide doesn’t necessarily mean better endurance. Feeling less sore doesn’t prove that strength or readiness for the next training session has recovered more quickly.

The same caution applies to animal studies, laboratory research, testimonials, and personal experience. These can help generate a hypothesis, but they can’t tell us with confidence what will happen when the product is used by actual people under real training conditions. Someone may genuinely believe that a supplement improved his energy, strength, or recovery, but that doesn’t separate the product's effect from changes in training, diet, sleep, expectations, or the simple fact that performance naturally varies from one day to the next.

I want to be very clear about this. I realize that many people who use these substances feel strongly that certain products work, and their personal experience may be all the proof they need. I’m not discounting that experience. In some cases, the product may legitimately be helping. In others, the person may believe it’s helping when the improvement is actually coming from something else. That’s the nature of anecdotal evidence. It can be real and honestly reported, but it can’t reliably tell us whether the same result will occur in other people or whether the product itself caused the improvement.

My job in this series is not to give you my opinion or repeat what other people believe. My job is to show you the evidence.

Every conclusion and every performance claim will be grounded in research, and we’ll examine that research critically. The fact that a study was published doesn’t automatically make its conclusion reliable. Some studies are poorly designed, too small, inadequately controlled, based on the wrong population, or focused on an outcome that doesn’t actually matter. Some findings are never replicated. Others may be statistically significant but too small to make any meaningful difference in the real world. We’re not going to accept a claim simply because someone can point to a research paper that appears to support it. We’ll scrutinize the study's quality, what was actually measured, and whether the conclusion is justified by the data.

Throughout this series, I’ll give the greatest weight to the highest-quality human research available and to outcomes that matter. Did the participants become stronger? Did they produce more power, complete more work, sustain a faster pace, recover their performance more quickly, or gain meaningful muscle mass? Was the effect repeated in more than one study? Was it seen in trained people or only in beginners? Was the improvement large enough to matter outside a research paper? These details are far more important than whether a study reported a statistically significant change in a laboratory value.

The evidence for each intervention will be placed into one of four categories:

Strong evidence — Multiple good-quality human studies consistently demonstrate a meaningful effect.

Moderate or context-specific evidence — The intervention appears to work, but only for certain types of exercise, populations, doses, or circumstances.

Preliminary or inconsistent evidence — Some findings are encouraging, but the research remains limited, conflicting, or inadequately replicated.

Insufficient evidence — The claims are supported mainly by theory, animal research, testimonials, or weak human data.

Even when something works, that doesn’t automatically mean it’s worth using. Every intervention will therefore receive a separate practical verdict based on the magnitude of benefit, medical risk, cost, product quality, and the uncertainty that remains. Some products may be effective and reasonable. Others may be useful only in narrow circumstances. Some may be harmless but unnecessary. Others may produce substantial effects while carrying risks that make them inappropriate for routine performance enhancement.

That distinction will remain central throughout the series. We’re not simply asking whether a substance affects the body. We’re asking whether it produces a meaningful improvement in human physical performance and whether that improvement is worth the risk, cost, and uncertainty required to obtain it.

The Performance-Enhancement Landscape

Before we examine each category in detail, it is helpful to step back and look at the overall performance-enhancement landscape. The products and substances men use don’t fall neatly into categories such as “good” and “bad,” “natural” and “unnatural,” or “legal” and “illegal.” The more useful comparison is between how convincing the evidence is that something meaningfully improves performance and how much risk, uncertainty, or concern about product quality comes with it.