Muscle Building Net

If you do several repetitions of one exercise, less muscle fibres are activated simultaneously than with a maximum test.

Your body always spares a part of its muscle fibres. Maximum test or repetitions – a part of the fibres is kept as a back-up.

Every time a muscle fibre is tired, it’s work will be done by a “relaxing” one.
The tired fibres relax while the others do their work. As soon as one fibre is totally regenerated, it will be used again.

This goes on, until there aren’t enough relaxed muscle fibres available simultaneously to do the necessary strength output.

At this time no strict repetition is possible. The set comes to an end. The underlined sentence’s emphasis is in “simultaneous”. Some muscle fibres take a rest, but they aren’t sufficient to do the necessary effort.

According to scientific examinations 30% of your muscle fibres are tired at the end of one set.