I don’t have time to search for references now. I have to prepare dinner.
But I’ve done a lot of reading on nutrition supplements and so-called “ergogenic” supplements, and I’ll tell you what I have read.
Creatine will help with fast speed work. Your body uses creatine phosphate when you first start exercising, as it does not have time to produce enough ATP (adenine triphosphate). So it helps those who do speed work. It will store water in your muscles and that’s a caveat.
Exercise, as little as 10 minutes a day, helps your cardiovascular system. In fact, aerobic exercise over 30 minutes a day is mainly a waste of time unless you are training for something specific, such as a marathon or ultramarathon, triathlon, etc. You will gain somewhat, but the gains are minuscule after 30 minutes.
“Nutrition supplements” is vague. Are you including vitamins, minerals, energy bars, ergogenic aides, etc.? It’s best to obtain your vitamins and minerals from food, but sometimes it is necessary to ingest tablets. A case in point is the recent studies of the benefits of “vitamin” D (which is actually a hormone). The older you get the more you need, and those over 60 need at least a gram a day, with women needing more. Sunshine helps, but, of course, too much sun is not a good thing. Studies on some other vitamins do indicate that certain vitamins, such as vitamin A, are better obtained through the previtamins (beta-carotene, for example) in food or directly from certain foods, than through tablets.
I’ve always taken vitamin C and other antioxidants since I do exercise a lot and exercise creates free radicals. However, I read a recent discussion based on studies that the exercise itself causes the body to create the antioxidants necessary to sop up the free radicals, and that ingesting additional antioxidants is contraindicated.
Most people get enough protein from food, even body builders, as the requirements are not much. Those who exercise and lift weights do need more than sedentary people, but a normal diet will provide enough. Dr. Mirkin has a lot to say on these topics, if you search for “Dr. Mirkin.”
I do use gels or blocks when I run over 10 miles, since eating food is not a good idea while running and these gels or blocks can give you the necessary carbs and electrolytes you need. However, when I did do a 50-miler (in Chicago, incidentally, the AMJA ultramarathon) back when I lived in Illinois (and that run was in the early 80s), I did eat a lot of carbs every 10 miles, in the form of fruits and chocolates. (The run was 5 loops around Lincoln Park, with each loop being 10 miles, so it was easy to stash those foods in one spot.)