How the NCAA sorts banned drugs into classes, what steroids and hormone mimetics actually do to performance and health, and the specific evidence-based dosing behind creatine, caffeine, beta-alanine, sodium bicarbonate, and HMB.
What actually shows up on the exam
An ergogenic aid is anything used to improve performance beyond what training and normal nutrition alone would produce — the category is broader than "drugs." It spans nutritional aids (supplements), pharmacological agents (steroids, stimulants), physiological/mechanical aids (blood doping, altitude tents), and even psychological techniques. A CSCS professional doesn't prescribe or administer any of these — the job is to know the categories, understand the real evidence behind each one, recognize the signs of misuse, and steer athletes toward what's both legal and actually effective.
Several organizations maintain overlapping — but not identical — banned-substance lists. The World Anti-Doping Agency (WADA) publishes the global Prohibited List that governs Olympic and international competition; national bodies like the U.S. Anti-Doping Agency (USADA) enforce that list domestically for Olympic-eligible sport. Collegiate athletics runs on its own list: the NCAA's banned drug classes, which is the framework the CSCS exam draws from most directly. Testing is done through urine and blood samples, both in and out of competition season.
The single most important operating principle across all of these systems is strict liability: an athlete is held responsible for any banned substance found in their body, whether it got there deliberately, through a contaminated supplement, or through a medication they didn't realize was restricted. That's precisely why athletes subject to testing are steered toward third-party-certified products rather than any supplement off a store shelf.
| Class | What it's meant to do | Representative examples |
|---|---|---|
| Stimulants | Heighten alertness, mask fatigue, sharpen focus | Amphetamine, ephedrine, methylphenidate |
| Anabolic agents | Drive tissue growth through androgen-receptor signaling | Testosterone, nandrolone, stanozolol |
| Diuretics / masking agents | Dilute urine or otherwise conceal other banned substances from a test | Furosemide, hydrochlorothiazide, probenecid |
| Street drugs | Restricted for behavioral and health reasons more than performance | Heroin, THC/marijuana above a set threshold |
| Peptide hormones and analogues | Mimic or trigger release of anabolic or erythropoietic hormones | hGH, EPO, hCG, insulin |
| Anti-estrogens | Block estrogen's effects — often used alongside steroids to offset side effects | Clomiphene, tamoxifen, anastrozole |
| Beta-2 agonists | Approved medically for asthma; misused for a mild anabolic/fat-loss effect | Clenbuterol, high-dose albuterol |
Where people lose points
Diuretics land in the banned list not because they enhance performance directly, but because they can dilute a urine sample enough to hide other banned substances — that's the "masking agent" half of the category. And because dietary supplements aren't required to prove their contents before hitting the shelf (see below), an athlete can test positive from a contaminated product they never intended to take — strict liability means that's still on them.
Two broad strategies show up under this heading: taking a synthetic version of the body's own anabolic steroid hormone (testosterone) or something chemically related to it, versus using an injectable protein or peptide hormone — or something that mimics one — to push a specific physiological system harder than it would run on its own.
Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone, carrying two linked properties in different proportions: an anabolic effect (tissue-building) and an androgenic effect (masculinizing). They work by binding androgen receptors inside muscle and other tissue, which upregulates the genes responsible for protein synthesis. A second mechanism adds to the effect: AAS also occupy glucocorticoid receptors, blunting cortisol's normal muscle-breakdown signal — so part of what makes steroids effective is less breakdown, not just more building.
Route of administration matters for risk. Oral steroids are chemically modified (17-alpha-alkylated) so they survive first-pass liver metabolism — the same modification that makes them the most liver-toxic form. Injectable esters bypass that first pass through the liver and carry a different risk profile.
| Domain | What the evidence shows |
|---|---|
| Maximal strength | Reliably increases — especially alongside a structured resistance program and a caloric/protein surplus |
| Lean body mass | Measurably increases; part muscle protein accretion, part fluid retention |
| Aerobic endurance | Little to no consistent benefit — the anabolic pathway doesn't translate into aerobic capacity |
| Cardiovascular risk | Worsens lipid profile (LDL up, HDL down), raises blood pressure, linked to left-ventricular hypertrophy |
| Hepatic risk | Concentrated in oral, 17-alpha-alkylated forms — cholestasis, and rarely, liver tumors |
| Endocrine/reproductive risk | Suppresses the body's own testosterone production (HPTA suppression); can cause testicular atrophy and infertility; excess androgen aromatizes to estrogen, which can trigger gynecomastia |
| Psychiatric risk | Mood swings, irritability/aggression, and a genuine risk of psychological dependence |
Why the effect is real but the tradeoff is steep
The exam isn't testing whether steroids "work" — they measurably do, on both strength and mass. What it's testing is whether you understand that the same androgen-receptor mechanism producing those gains is inseparable from the downstream endocrine, cardiovascular, and hepatic costs. There's no dose that gets one without some exposure to the other.
Beyond steroids, a handful of naturally occurring protein and peptide hormones get used — or mimicked — for a performance edge. Each one targets a different physiological lever, and each one carries its own gap between the claim and the evidence.
| Agent | Claimed effect | What the evidence shows |
|---|---|---|
| Human growth hormone (hGH) | More lean mass, less fat, faster recovery | Modest body-composition changes in some studies; doesn't reliably add strength or power beyond what training alone produces |
| IGF-1 | Same anabolic promise as hGH, since it's the hormone that mediates many of GH's downstream effects | Thin evidence base in healthy trained athletes; expensive, and largely unproven at the doses actually used |
| Erythropoietin (EPO) | More red blood cells → greater oxygen-carrying capacity → better endurance performance | One of the few agents with real, well-documented performance benefit — which is exactly why endurance sport tests for it so aggressively |
| Insulin | Drives glucose and amino acids into muscle for a stronger anabolic signal | Some theoretical support, but the margin between an effective dose and a fatal hypoglycemic one is dangerously narrow |
| Prohormones (e.g., androstenedione) | An oral "precursor" the body converts into testosterone | Conversion is inefficient and heavily reduced by first-pass liver metabolism — research generally shows little to no meaningful rise in circulating testosterone |
| System | What to look for |
|---|---|
| Skin | Sudden, severe acne — especially on the back and shoulders |
| Musculoskeletal | Rapid, disproportionate gains in muscle mass and body weight |
| Male reproductive | Testicular atrophy, gynecomastia, reduced fertility |
| Female-specific | Voice deepening, excess facial/body hair, menstrual irregularity — changes that are often not fully reversible |
| Psychological | Mood swings, irritability, aggression, and dependence |
| Cardiovascular | Elevated blood pressure, edema/water retention |
| Hepatic | Jaundice, right-upper-quadrant pain (most associated with oral steroid use) |
| Injection-related | Needle marks and localized infection at injection sites |
A quick way to sort the hormone table
Only EPO has a strong, direct performance benefit backed by solid evidence — it's the one on this list actually worth testing hard for. hGH and IGF-1 promise a lot but deliver modest, inconsistent results in real athletes. Insulin is the most acutely dangerous of the group. Prohormones mostly just don't work as advertised.
In the U.S., dietary supplements are regulated under the Dietary Supplement Health and Education Act (DSHEA), which treats them more like food than like drugs — a manufacturer doesn't have to prove a supplement is safe or effective before it goes on the shelf, only avoid making explicit disease-treatment claims. That light-touch regulation is exactly why product quality and label accuracy vary so widely, and why athletes subject to drug testing are steered toward third-party-certified products (e.g., NSF Certified for Sport, Informed Sport) rather than anything untested — tying directly back to the strict-liability principle covered earlier.
Creatine is a naturally occurring compound synthesized from three amino acids (arginine, glycine, and methionine) and stored mostly as phosphocreatine in skeletal muscle. Phosphocreatine is the fuel for the phosphagen energy system — the fastest way the body has to resynthesize ATP during brief, maximal-intensity effort. Supplementing pushes muscle phosphocreatine stores higher than diet alone typically achieves, which means faster ATP resynthesis between explosive efforts, more total work completed per set, and — accumulated over a training block — a real edge in the strength and power adaptations that follow.
Creatine is the single most researched ergogenic supplement on the market, and the evidence base is unusually consistent: clear benefit for repeated short, high-intensity bouts (sprinting, jumping, heavy lifting), little to no benefit for pure aerobic endurance, and a long-term safety record in healthy individuals at recommended doses. The commonly cited "kidney damage" concern isn't supported by research in people with normal kidney function.
Four other supplements come up often enough on the exam to know cold — each with its own dose, its own mechanism, and its own narrow window of effort where it actually helps.
| Supplement | Typical dose | Mechanism | Verdict |
|---|---|---|---|
| Creatine | ~20 g/day loading (5–7 days) → 3–5 g/day maintenance; or 3–5 g/day from the start | Expands muscle phosphocreatine stores for faster ATP resynthesis | Strongly supported |
| Caffeine | ~3–6 mg/kg, 30–60 min pre-exercise | Blocks CNS adenosine receptors; lowers perceived exertion | Strongly supported |
| Beta-alanine | ~3.2–6.4 g/day, in smaller split doses | Raises muscle carnosine, buffering H⁺ during glycolytic effort | Well supported (1–4 min efforts) |
| Sodium bicarbonate | ~0.3 g/kg, 60–90 min pre-exercise | Raises extracellular buffering capacity, pulling H⁺ out of the muscle | Well supported (1–7 min efforts) |
| HMB | ~3 g/day | Slows muscle protein breakdown (anti-catabolic) | Mixed — mainly benefits untrained or heavily stressed lifters |
The exam's evidence hierarchy, in one line
Creatine and caffeine sit at the top — the largest, most consistent evidence base of anything covered in this chapter, including the hormonal agents. Beta-alanine and sodium bicarbonate are well supported but only within a narrow, specific window of effort duration. HMB is the most population-dependent of the five — real for some lifters, negligible for others.
A drug-tested athlete's sample dilutes a banned stimulant below the detectable threshold. Which NCAA banned drug class does the diluting agent most likely belong to?
B. Diuretics and masking agents are banned specifically because they can conceal other substances — including by diluting urine — not because they build tissue or boost stimulation on their own.
An athlete tests positive after unknowingly taking a contaminated pre-workout supplement. Under the principle of strict liability, what's the outcome?
B. Strict liability puts responsibility for anything found in the body on the athlete, regardless of how it got there — which is exactly why third-party-certified supplements matter for tested athletes.
Which mechanism lets anabolic-androgenic steroids reduce muscle breakdown, separate from their effect on protein synthesis?
B. AAS bind androgen receptors to drive protein synthesis, and separately occupy glucocorticoid receptors — blunting cortisol's normal breakdown signal. That's the anti-catabolic half of how they work.
Which route of anabolic steroid administration carries the greatest hepatotoxicity risk, and why?
B. The 17-alpha-alkylation that lets an oral steroid survive the liver's first pass is the same modification responsible for its outsized liver toxicity compared to injectable esters.
Of the hormone-based ergogenic aids, which has the strongest, most consistent evidence for a direct performance benefit?
C. EPO's boost to red blood cell mass and oxygen-carrying capacity is well documented in endurance performance — unlike hGH, IGF-1, and prohormones, which all show modest or inconsistent effects in trained athletes.
A lifter wants to load creatine as fast as possible before switching to a maintenance dose. Which protocol matches the evidence-based approach?
B. The standard loading protocol is roughly 20 g/day split across the day for 5–7 days, followed by a 3–5 g/day maintenance dose. Skipping loading and starting at 3–5 g/day also works — it just takes about 3–4 weeks to fully saturate stores instead.
Which supplement's ergogenic effect depends on raising muscle carnosine content, and therefore requires weeks of chronic dosing rather than a single pre-exercise dose?
C. Beta-alanine is the rate-limiting precursor for carnosine synthesis, and muscle carnosine content only rises gradually — which is why beta-alanine is loaded chronically over weeks, unlike an acute pre-workout dose.
Sodium bicarbonate improves performance mainly in efforts of what duration, and through what mechanism?
B. Sodium bicarbonate raises extracellular pH and buffering capacity, steepening the gradient that pulls H⁺ out of working muscle — most useful for roughly 1–7 minute efforts that lean heavily on anaerobic glycolysis.
Which best describes HMB's primary mechanism and the population it benefits most?
B. HMB is primarily anti-catabolic. Its measurable benefit is largest in people under high training stress or new to resistance training — well-trained lifters see a much smaller, more mixed effect.
A female athlete using anabolic steroids develops a deepened voice and increased facial hair. What does this reflect about steroid side effects generally?
B. Voice deepening and hirsutism are androgenic effects — a direct consequence of the same androgen-receptor activity that also drives the anabolic (muscle-building) effect — and in women, some of these changes persist even after stopping use.
This chapter is original study material covering topics also addressed in Essentials of Strength Training and Conditioning, 5th edition (NSCA/Human Kinetics). It is an independent work, not a reproduction or paraphrase of that text. This guide is not affiliated with, endorsed by, or sponsored by the National Strength and Conditioning Association (NSCA). CSCS® and Certified Strength and Conditioning Specialist® are registered trademarks of the NSCA.