What is the purpose of using fitness supplements like protein and creatine? Do people still use them even if they consume a lot of protein-rich foods?

So again, if you don’t want to spend money on creatine, you don’t have to. Provided that you’re adhering to best practices (eating plenty of protein, getting enough sleep, limiting alcohol intake, etc.) your hard work in the gym will pay off.

As for what creatine actually does for lifters, it’s probably easier to show rather than tell - biochem was never my forte:

Beef is a great source of creatine, but you only get 2 grams of creatine for every pound of beef that you eat.

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There’s only so much you can do to make grilled chicken and lean sirloin flavorful, particularly if you’re watching your sodium. Protein supplements allow me to add some novelty to my day, even if I’m just trying a new flavor of whey. Whole foods are the foundation of my diet, but protein supplements sure do come in handy for helping me meet my daily needs. To be clear, if you have the time and the inclination, you can absolutely eschew protein supplements and rely solely on protein rich foods…but I have neither.

Creatine is a different story. Yes, it’s readily available animal proteins, so you could get all you need by eating a protein rich diet. The problem is that you would need to eat a shit ton of meat to get the daily, recommended dose of 5g of creatine:

Creatine improves numerous aspects of strength and power. The average increase may be around 5%.

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I take some manner of protein supplement (I.e. a shake, a bar, Oats Over Night, etc.) at least twice per day for several reasons. For one, it’s just convenient. I’ve never been great about meal prep because I’m almost always pressed for time. Throwing some water and whey isolate in a shaker bottle is quicker and easier than preparing three to four protein rich meals to eat every day. Unwrapping a Barebell protein bar is quicker and easier still.

Protein is very filling - that’s part of the reason it’s so integral for people who want to lose weight. So if I tried eating 40 oz of beef every day, I’m pretty sure I’d spend most of my week nauseous. I’ll take the tiny scoop of sour tasting powdered creatine.

Creatine is not magic. If you can only bench the bar, consistently taking creatine will not empower to do 225 for reps by the end of the month. Creatine just gives you a little extra “Oomph!” to crank out those last, agonizing reps. And those last, agonizing reps drive a ton of muscle adaptation - hence why creatine optimizes muscle growth. However, any gains you get from taking creatine are going to be relatively modest:

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The other reason I like protein supplements is the variety of flavors.

If you’re training hard with the goal of building muscle, you need 5 grams of daily creatine for optimal benefits.

Let’s do some math. To get the 5 grams for the maintenance daily supplement dose of creatine, you’d need to eat 2-1/2 lbs of beef.

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With all due respect to Bobby Hill, I’m not about this life: