Now there is a way too common thing now a days for people to be not implementing correct rest time in between sets. I am let me tell you this first it is not a one-dimensional answer. You might not even know the negative affects either of training with incorrect rest time in between sets.

This central training concept is way too often mis-understood nowadays and the truth finally needs to be revealed in it's entirety.

The time between sets is very important because it is your short-term recovery period for your muscle fibers.

When you physically perform the contractions on your muscles many physiological reactions are taking place, internally. This does a 'tear' on your muscles, seriously. These can be summed up as molecular activities.

What training does is push your muscles to the limit with these molecular activities, which produces the best results in the end considering you muscles current state or 'experience'. Your recovery period between sets allows you to repeat this process until you have done enough damage for that session.

Your muscles need to be ready for every set so you can perform maximum intensity and so they can actually complete the desired set amount to positive failure.

For Maximum Muscle Growth

Slow-Twitch Fiber = Less Rest Time Between Sets

Fast-Twitch Fiber = More Rest Time Between Sets

When you start you should keep the rest between sets around 2 to 3 minutes.

This time frame allows the fibers to recover its internal molecular energy and cleanse out any lactic acid hanging around from the last set and to reconstruct oxygenic capacity. When your muscles progress more they will be able to have a shorter short-term recovery period. They need it to see quicker gains in the end.

Muscle

Muscles need time to heal, once a week for directly hitting a muscle is fine. Muscles grow when muscle fibers are damaged and repair themselves following a workout. Muscles is a movement, it is our life.

Muscles are the 'slaves' of the CNS, and when the CNS calls for a movement, it never calls in individual muscles separately. Muscle recovery can only happen in the presence of ample amino acids and the only source for amino acids is dietary protein. Muscles, tendons and ligaments tend to shorten over a period of time, which limits our range of motion and renders us more liable to injury when sudden stresses are placed on these structures. Muscle has one simple function -- it contracts.

Muscle takes work, time, and dedication, more than most people are willing to devote. Muscle & Fitness becomes the official journal of the IFBB. The muscles are revealed through a combination of fat loss, oils, and tanning (or tanning lotions) which combined with lighting make the definition of the muscle fibres more distinct.