Supplementation must be tailored to your body. You should not under any circumstances copy the supplementation plan of your friend from the gym, because he may have a completely different need for certain nutrients. Surely his diet is also different, and with it you can also supplement certain deficiencies for various substances. So first do some basic research, which you should do at least once a year, and only then analyze the results with a doctor or dietician. On this basis, select individual supplements for athletes. And if a serious deficiency has already occurred in your body, you will most likely feel its effects on a daily basis, because the symptoms of vitamin and mineral deficiencies are very characteristic and it is rather impossible not to notice them.
However, there are dietary supplements that literally everyone should take regularly, especially people who exercise. One of them is magnesium. It has a great effect on the nervous system and strengthens connections between nerves. It is also an excellent remedy for people who suffer from problems with concentration during workouts, because it aids concentration. A lack of magnesium also manifests itself in muscle tremors, a constant feeling of fatigue and a general lack of energy. If you are suffering from its deficiency, you probably find it hard to focus, feel perpetual fatigue and increasingly give up on even those scheduled workouts. In all such situations, you should start taking magnesium supplements for athletes. Your diet can also provide it, as long as you include plenty of nuts (especially almonds!), cereals, oatmeal, wholemeal bread and… chocolate! chocolate!
However, the most popular supplements are those that are a mixture of different vitamins and minerals. And exactly these should not be bought or taken. If the preparation is – according to the manufacturer – good for everything, in fact it will not do anything special. So it is better to buy separately vitamin D3 and magnesium, instead of reaching for the popular and very fashionable multivitamins.