Every successful fitness model has followed a plan in life that has enabled him to understand his body perfectly. Everybody has different body needs that he must understand in order to work out properly.
The workout should be planned by keeping three things in body type, goals and time. Body type will assess the proper potential of that person that he could reach physically. Now the 3 week diet system is being heard again and again in the fitness industry. You can read all about it on wisejug.
The reason behind this is as it is focused more on the goals and the time required reaching it. It takes into account the best real possible goal that person could achieve in the time period of 3 weeks. Three weeks looks like a shorter time span, but when it comes to working out, 21 days are enough to start seeing results with hard consistent work. To see results, you must stick to the plan and be consistent. Otherwise, you will waste time and resources.
The shorter the time span of a diet plan, the more consistent and easily a person can follow because with the long-term goals it is hard to carry on. People find it easy to stay motivated and stay on the track with short-term goals rather than long-term, as it is human nature.