In the field of providing safe and effective equipment for physical training appropriate adjustment of loading levels for the targeted users is very important. Most training machines to date offer only fixed and coarse load adjustment. This paper details an advanced leg muscle training machine that has an intelligent load control system. The load control is provided by monitoring the user's muscular condition by means of a muscle stiffness sensor as well as pressure being exerted on the machine. The loading can then be adapted continuously to optimally suit the user's needs. The prototype demonstrated that the proposed machine has excellent load control abilities providing effective and safe training using dynamic load control and automatic restriction of loading levels based on the user's muscle contraction levels