We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Over the past six months or so, in our posts about physical fitness, we have always made a distinction between strength training and the other useful activities which build strength minimally or not at all but are more maintenance-oriented and endurance-oriented such as cardio intervals, calisthenics, heavy calisthenics, high-rep weights, isometrics, pliometrics, recreational sports, or mucking out the barn. In other words, activities which use your muscles - or "tone" your muscles, but do not build them.
The latter activities so not require any more protein than one's usual diet.
Strength training is ideally part of any fitness program, but most people don't do much of it because it hurts. I am not talking about "body-building" in the extreme sense, just strength-building. Strength-building entails moving heavy things in order to break down, damage, muscle tissue. Generally-speaking, if you can do more than 12 reps you are doing a warm-up or working on endurance, not so much muscle-building so it's time to raise the weight. The strength-building part occurs during several days afterwards, the recovery phase. As with bone fractures, your body's repair leaves it stronger than it was before you broke it down.
Muscle repair and building requires more protein than the average diet, but probably not a whole lot more. There is a lot of wacky advice out there, but for those who move heavy weight two or three times/week, I think this article is reasonable: Are You Eating Enough Protein To Build Muscle?
The article claims that, for a male, a serious muscle-building program with heavy weight, 2-3 times/week, needs up to 1 gm protein/lb body weight daily. (On average, non-pregnant women have about half the dietary needs of men). It's all approximate, of course. And who knows how many grams of protein there are in my particular hamburger anyway? With a whey powder, you know what you're getting if you like that sort of thing.
(FYI, an average burger has around 20-30 gms, an egg 6 gms, a glass of whole milk about 8 gms. You can Google all food numbers. Whey powder is labeled by gms per scoop.)
Actually, people advising people to "inform themselves" shouldn't be referencing "authoritative" links that have a "shop" section where they can buy "t-shirts", "cookbook", "totes", etc., from the authority. Sort of kills the pretense of credibility........
I read posts every day assuming and arguing that most of us need more protein--often referring to "high quality" protein, whatever that is. Most of this kind of talk is hilariously untethered from evidence. It's not uncommon for people to argue that almost every kind of food calorie available is "empty calories" by some metric or another--carbs are bad, fat is bad, everything's bad. I wonder sometimes if they even know what a calorie is, or what food is for, or what "nutrients" are. Most of us get in trouble not because of what we eat, but because of how much we eat: way too much.
The linked article was certainly correct in noting that too much protein can put a strain on body systems like the kidney, and in noting that it's not really rocket science to ensure that your diet contains all nine essential amino acids, whether or not you choose to eat meat. Meat is an extremely tasty and convenient way to get complete protein. Combinations of various non-animal-based food generally require a bit more attention, but they're also usually cheaper, they taste great, they're full of useful fiber, and they'll certainly provide you with as much protein as you need. Kwashiorkor--protein deficiency--is nearly unheard of out of the context of extremely severe famine or unusually isolated populations heavily dependent on a single food, like cassava. Most famine victims don't need more protein, they just need more calories.