However in reality, for most of history, people have stayed fit without any special methods that derive from contemporary molecular biology and so perhaps the jocks were all that were needed? In fact Aristotle mocked the 'ascetic' lifestyle and specific dietary demands of Herodicus who was the 'original' exercise scientist or kinesologist like 2500 years ago!
BUT in a age of internet photo shops, 'supplements' and 'expert and specialized programming', the role of science is to wear glasses and a white lab coat and stand behind some spray tanned bodybuilder and 'verify' his claim that MegaPump42 will pack on LBM faster then any steroid and reverse aging, and raise i.q. enough to count over 12 reps, etc. Seriously go pick up a muscle rag and look at the 'advertorials' and you will see the bodybuilder with a scientist standing somewhere or at least a molecule symbol of something to give it 'lab cred'. So let me reiterate. The role of science (the nerds) in fitness is to give some sense of authority to the ad copy since anyone who knows how this science stuff really works will tell you a single study doesn't mean much and bad studies or really old studies being used to verify claims are just dishonest. Such is the fascinating interconnections of academia and business. Furthermore, since PUBMED is full of papers- one can easily cherry pick studies to back up just about any claim, and we see that happen all the time. For example, studies showed Boron increased testosterone in pregnant females temporarily in the 60's or something like that-TRANSLATE TO AD COPY- scientists discover 'chemical' that increases human muscle growth and fat loss 500%! SO what role does science play in fitness? Well a long term role is to verify and invent ideas that can help people, but it is a painfully long and slow process that is under constant revision and there is no real sense of absolute stability in any of the findings.
SO we now come to an age old practice and school of philosophy- Skepticism- from the ancients through Hume and what it means today in relation to 'sports science.' While scientists should be skeptical, skepticism finds its roots in the philosophical questioning of everything. Hell science is actually philosophy but that is another story but for now please enjoy this 3 minute cartoon on the life of David Hume.