In past issues of Applied Metabolics, I've discussed in-depth issues related to protein timing. This relates to the idea that ingesting protein at specific times produces more of an anabolic effect in muscle compared to other times. Timing also relates to carbohydrates, since depending on the amount of time and frequency involved, replenishing exhausted muscle glycogen stores can play a critical role in exercise performance. More recently, an emerging sports nutrition concept has been that of ingesting a lower carbohydrate diet while still engaging in the same level of exercise or sports participation. The theory behind this is that training with the depleted carbohydrate stores that result from not ingesting sufficient carbohydrates will cause you to use more stored fat as an energy source. Since dietary fat supplies over twice the calorie content of carbohydrates (4 calories per gram of carbohydrate compared to 9 1/2 calories per gram of fat) the idea is that tapping into fat stores will increase muscular endurance without causing a loss of lean mass or muscle. In addition, ingesting a low-carb diet under exercise conditions may promote the increased genesis of mitochondria, cellular structures that are the site of both energy production as ATP and fat oxidation. Having more cellular mitochondria can make muscle far more efficient, and there is evidence that a loss of mitochondria with age (mainly due to lack of adequate physical activity--use it or lose it) is a major cause of the loss of lean mass common starting at age 40. Other scientists, however, suggest that under high-intensity exercise conditions, carbohydrate is still required in the diet to prevent premature muscle fatigue produced under high-intensity exercise conditions.
But besides protein and carbohydrates, timing and dose are also important in relation to other sports supplements. This is particularly true with supplements that may aid recovery and energy production during exercise. Timing is less critical for other food supplements, such as vitamins and minerals, although dosage still is important. Too much of any particular nutrient can cause an imbalance in other nutrients. In some cases, ingesting an excessive dose of one nutrient may even cause the excretion of another, equally essential nutrient. This scenario is common with many minerals. For example, ingesting too much of the trace mineral zinc can promote the excretion of another trace mineral, copper. Ingesting too much calcium can block zinc uptake, and so on. This sounds worse than it is because the body can adjust mineral intake according to need. What this means is that if you have low blood or tissue levels of any particular mineral, the body will upgrade the absorption of that particular mineral. Conversely, if tissue and blood levels are replete in any mineral, less of the mineral will be absorbed . . .