Science Corner 62 | The Fitness Showdown Study: Three Contenders, One Crown

In one corner: creatine, the reigning king of the weight room. In another: protein, the workhorse that never goes out of style. And in the third: omega-3s, the quiet contender that most people underestimate.

Three supplements. Three decades of research. One question that never seems to get a clean answer: which one is actually better for your fitness?

Researchers at Sejong University decided to find out. They pulled together 35 randomized controlled trials, 1,211 trained athletes, and ran a network meta-analysis, a method that lets you rank competing interventions against each other even when they've never gone head-to-head in a single trial. Three supplements. Three outcomes: strength, endurance, and recovery. One bracket.

Let's see how it played out.

Three supplements. Three outcomes. One bracket.

Round 1: Strength

Creatine topped the strength rankings, and it wasn't particularly close. The researchers used a scoring method called SUCRA to rank each supplement, which reflects the probability that a given supplement is the best option for a particular outcome. Think of it as a leaderboard percentage: the closer to 100%, the stronger the case. Creatine scored 82% for strength. Protein came in second at 68%. Omega-3s ranked third, and its effect on strength wasn't statistically meaningful.

Here's why creatine has such a consistent edge for strength-focused training:

• It refuels your muscles faster. Your muscles run on ATP, a molecule that depletes quickly during high-intensity efforts. Creatine increases the phosphocreatine stored in your muscles, which speeds up ATP regeneration between reps. More fuel available means more force produced.

• It works best for explosive efforts. The data showed creatine's advantage was especially pronounced in power-based sports like sprinting and weightlifting, compared to mixed training that blends strength and cardio. The more explosive the demand, the bigger the benefit.

• Protein is a close second. The gap between creatine and protein for strength wasn't statistically significant. But creatine was significantly better than omega-3 for this outcome.

Round 1 goes to creatine.

Round 2: Endurance

Here's where things get interesting. The supplement that ranked highest for endurance performance wasn't omega-3. It wasn't creatine. It was protein, scoring 85% on the SUCRA leaderboard for this outcome. Creatine ranked last, which also makes sense mechanistically: what creatine does for explosive, short-burst efforts doesn't translate to sustained aerobic work.

The likely explanation for protein's endurance edge involves mitochondria, the tiny structures inside your cells that generate energy for sustained exercise. Adequate protein intake supports building more of them. It also helps preserve muscle mass during heavy training blocks and supports energy replenishment between sessions. There's a timing caveat worth noting: the benefit was strongest in studies that ran longer than eight weeks. Shorter interventions showed a much smaller effect. Protein for endurance is a slow burn. Consistency matters more than any single dose.

Round 2 goes to protein.

Round 3: Recovery

This is where omega-3 makes its case. For recovery outcomes, including muscle soreness, markers of muscle damage in the blood, and the ability to perform well again after a hard session, omega-3 ranked first with an 89% SUCRA score. It also posted the strongest effect of any supplement across any of the three outcomes in the entire analysis.

The mechanism centers on inflammation. EPA and DHA, the active fatty acids in fish oil, appear to dial down the inflammatory response that follows hard training. Less systemic inflammation means faster tissue recovery and less soreness between sessions.

There's a dose threshold worth knowing: the benefit was only statistically significant when combined EPA and DHA intake exceeded 2 grams per day. Lower doses showed a trend but not a meaningful effect. For context, most standard fish oil capsules contain around 300 to 600 milligrams of combined EPA and DHA, which means you likely need three to six capsules daily to hit that threshold. Check the label, not just the total fish oil amount.

Then there's the protein finding, which deserves its own moment.

Protein, the supplement most associated with post-workout recovery, didn't show a statistically significant recovery benefit in this analysis. That's worth sitting with.

It's a counterintuitive result, but the authors have a reasonable explanation. Trained athletes, the population studied here, likely already consume adequate protein through their regular diet. When your baseline is already sufficient, adding more doesn't move the needle much on acute recovery markers like soreness and muscle damage. Creatine, interestingly, did show a small but statistically significant recovery benefit, which the researchers attributed to cellular hydration and membrane stabilization rather than muscle repair.

Round 3 goes to omega-3.

So Who Wins?

After three rounds, the scorecard reads: one win each. Creatine for strength. Protein for endurance. Omega-3 for recovery.

There is no overall champion. And that's actually the most useful finding in the study.

These three supplements aren't competing. They're specialists. If you're trying to optimize for a specific outcome, here's what the evidence supports:

• For strength: Creatine is the clearest choice. Aim for ~5 grams per day. The effect is consistent, the mechanism is well understood, and it's one of the most studied supplements in sports nutrition.

• For endurance: Prioritize protein at an optimal daily intake, around 1.4 to 2.0 grams per kilogram of body weight. Give it time. The benefit builds over weeks, not days.

• For recovery: Omega-3 at more than 2 grams of combined EPA and DHA daily has the strongest data of the three. Check your label carefully, most capsules require you to take several to hit that target.

If you're training for general fitness with no single dominant goal, the simple answer is that all three are worth considering. Each one addresses something the others don't, and there's no meaningful downside to running all three at evidence-based doses.

One important caveat before you overhaul your stack: every study in this analysis used trained athletes with at least six months of structured training under their belt. These are people who already eat well, recover intentionally, and have adapted to consistent training loads. If you're earlier in your fitness journey, the effects might look different. The directional findings still hold, but the magnitude may not translate one-to-one.

One more thing the data can't tell you: what happens when you take all three together. This study looked at each supplement in isolation. Many people stack all three simultaneously, and whether they amplify each other, interact in unexpected ways, or simply each do their own thing in parallel remains an open question. That's a study worth running.

What the data definitely won't do for you is put in the work. The athletes in these studies were training consistently, eating well, and recovering intentionally. The supplements supported that foundation. They didn't replace it.

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Personal note from Jordan

Before I was at SuppCo, I spent years running an exercise physiology lab studying performance-based supplements. Creatine and protein were central to almost everything we looked at. They were the obvious candidates, the ones with the strongest mechanistic rationale and the deepest research base. We ran protocols, measured outputs, argued about dosing windows. I know these two supplements the way you know something you've spent years with.

Fish oil was never on the radar. Not for performance. We thought of omega-3 as a cardiovascular supplement, something clinicians recommended to older patients, not something an athlete would reach for to get more out of their training. Seeing it rank first for recovery in a well-designed network meta-analysis, with the strongest effect of any supplement across any outcome in the entire study, is wildly interesting to me. The kind of surprising that makes you reassess assumptions you didn't realize you were still carrying.

I take all three as part of my daily stack… and have for a long time. Creatine, protein, fish oil. Partly because the evidence supports it, and partly because after years of studying this stuff, I've come to believe they're each doing something the others aren't. This paper is the clearest confirmation I've seen of that intuition.

My takeaway isn't about picking a winner. It's about knowing what you're training for, and building your stack around that answer. The science is finally good enough to help you with that journey.