dorettas@iddic.UUCP (Doretta Schrock) (11/14/85)
Michael Thompson writes: > I have started weight lifting and have some questions about human muscles. > > Why do muscles get sore? Is it an injury? Like a bruising? Why does > it take several hours to a day before they feel sore? Should I force > myself to lift weights if my muscles are sore or can I injure myself that > way? If my muscles don't get sore, does that mean I am not making > progress? Yes and no :-). Your muscles get sore because of the build up of the products of anaerobic respiration (mainly lactic and pyruvic acid). Your muscles have the ability to use glucose (sugar) for power either with or without oxygen. If you work them slowly and steadily, there will be enough oxygen supplied for them to burn glucose efficiently. Your muscles will build up, and you won't get sore. But, if you work them quickly and heavily (as in weight lifting), there isn't enough oxygen to go around, so they have to take a short- cut process that isn't as efficient, and leaves various products lying around. These take time to diffuse out of your muscles into your blood stream, especially if you stop using them suddenly (which is why you are told to "warm down" after lifting), and so build up to concentrations that you perceive as a dull ache. This doesn't really hhurt your muscles unless there is a whole lot of the acids around for a long time (if you're fairly healthy this shouldn't happen). There is some evidence that the ache is due to distension of the intra-muscular capillaries (this can also happen after getting an intra-muscular injection for example), but again, this shouldn't hurt you. The main reason you should wait a day or two between lifting sessions is that on a molecular level, your *are* doing damage to the muscle, and this gives it time to rest, repair, and get rid of any excess acids that are left. > What is it exactly that triggers muscle development in humans? Is there > some kind of chemical that gets released after physical exercise? When you contract and relax your muscle, millions of tiny molecules link up with each other, contract, relink, and finally relax (this is very difficult to explain without a picture...you might want to find a recent bio or physio book). The microscopic contractions of each of these molecule-linkages adds up to a visible contraction in the muscle. This is one reason that longer muscles tend to be more powerful. When you work the muscle, it contracts and expands a little beyond its "normal" limits, and some damage is done. Then, when the muscle is in a more resting state, the muscle cells repair the protein strands that were damaged. In doing so, they make each a little larger and/or make more of them in the cell. This makes the muscle stronger and somewhat bigger. The relationship between size and power of a muscle is not one-to-one, though. Muscle cells also store large quantities of glycogen (that is, "fat"), and if they are continually being heavily used, they will store more. That is why you see body-builders who have big muscles without necessarily being super-strong. > What kind of foods/diet promotes muscle growth? Should I eat lots of > protien? Carbohydrates? How important is diet for muscle growth? Should I > concentrate more on lifting weights than on following a particular > diet, or should my efforts in these areas be equally distributed? I am not a nutrition expert, but beyond following common sense, I would say that proteins and complex carbohydrates (potatoes, bread, etc.) would be two things to concentrate on (though *not* to an extreme -- ignoring any part of your body's needs will be foolhardy). Protein is needed for muscle repair, and carbohydrates -- in moderation -- will give your body the energy supply it needs. Sugar (glucose, dextrose, honey, etc.) will, to some extent, actually work *against* you, in that it lowers your blood- sugar level about 20 min after ingestion (it does not make people 'hyper'... if anything, it puts them to sleep!). Depending on how serious you are about this, follow a balanced diett (maybe heavy on the protein, esp. meat), work out, and if you need to, see a doctor or nutritionist. BEWARE of body- building fads, etc. > Is there anything else I can do to get maximum muscle growth in minimum > time with a minimum amount of pain? The Soviets (of course :-) have experitmented with low-level electrical stimulation of muscles to speed development. I don't know what, if anything, is being done with it right now. Aerobic excerise can be a good adjunct to a building program. Things like swimming, running, dancing, etc. are good at excercising your muscles with a minimum of pain (and boredom). Don't think that something like swimming won't build up your body, it will. And though it (or dancing, fencing, etc) won't always make a specific muscle group hurt, you *will* feel the difference. Mike Sellers <-- note the name difference from above!
jak@mtgzz.UUCP (j.a.kushner) (11/15/85)
Not to be picky, for this is a nice explanation, but some comments follow: > Michael Thompson writes: >> I have started weight lifting and have some questions about human muscles. >> >> Why do muscles get sore? Is it an injury? Like a bruising? Why does >> it take several hours to a day before they feel sore? Should I force >> myself to lift weights if my muscles are sore or can I injure myself that >> way? If my muscles don't get sore, does that mean I am not making >> progress? > >Yes and no :-). Your muscles get sore because of the build up of the products >of anaerobic respiration (mainly lactic and pyruvic acid). Your muscles have Pyruvate is not really the culprit. There is an equilibrium between the two which is pushed toward more lactate during anaerobic glycolysis, and this acid does 'burn'. >Muscle cells also store large quantities of glycogen (that is, "fat") Glycogen happens to be a complex carbohydrate; essentally a tree-like structure made up of many glucose molecules. In non-aerobically 'fit' individuals, carbohydrates provide the majority of fuel for metabolizing tissue (exercising muscles anaerobically). This is contrast to aerobically trained individuals who will utilize a lot of fatty acid for metabolism when exercising (running, swimming). Not exclusively, though, for as a biochem teacher once said, "Fats burn in the fire of carbohydrates" (Can't burn the fats without the carbohydrate intermediates in the various metabolic pathways (i.e. Krebs cycle). >> What kind of foods/diet promotes muscle growth? Should I eat lots of >> protien? Carbohydrates? How important is diet for muscle growth? Should I >> concentrate more on lifting weights than on following a particular >> diet, or should my efforts in these areas be equally distributed? >> Is there anything else I can do to get maximum muscle growth in minimum >> time with a minimum amount of pain? Of course there are steroids! The androgens help to create a difference in muscle mass between males and females. (I would not recommend this, though. Altering the normal production levels of endogenous hormones could lead to serious consequences) Jeff