Training for strength improves coordination. Your brain is a master switchboard that coordinates your muscles. Lifting weights does not interfere with brain function; it improves coordination in events that require strength, such as playing sports, working as a carpenter, opening a stuck door or beating a drum.
Moving a weight very slowly in sets of ten causes the same amount of damage as moving a much heavier weight rapidly, and causes the same type of muscle damage. Lifting lighter weights slowly is far less likely to cause injuries than heavy lifting.
Your brain does send an electrical impulse along nerves that enter muscles to cause them to contract. The electrical impulses generated by ab machines are so weak that they can't possibly cause contractions that strengthen muscles significantly. If they did give you enough electricity to strengthen your muscles, they would give you a very painful shock.
When I look at today's baseball players, I just can't believe how big they are. They are larger and stronger than the best players of the 1930s to 1970s. Babe Ruth, arguably the greatest hitter who ever lived, was a fat elephant with relatively small muscles and a huge belly compared to the average player today.
Should you exercise when you have a cold or the flu? Most doctors allow their patients to exercise when they have a cold, as long as they don't have a fever and their muscles don't hurt when they exercise.
