the question was asked, "can weight be added too quickly, and what is appropriate?"

lifting too heavy too quickly can increase the risk of injury. as an ex-trainer, my recommendation for beginners or deconditioned individuals has always been to start off light and work their way up to moderate weights within the first couple weeks. this will aide in conditioning thru mitochondrial re-education, as well as add a progessive strengthening factor to the connective tissues. this will also allow the person to overcome the initial soreness with more moderate tissue damage as opposed to extensive damage when the cellular components are not yet ready to deal with as much repair.

there is no magic number for how much weight to add and when. start off light. find a weight that is just heavy enough to do 20 reps to unassisted failure. use this load to familiarize yourself with the movements, focusing on perfecting proper form technique. without proper form, the risk of injury in drastically increased. after a week or so of this weight, increase to a load just heavy enough to get 12-15 reps to unassisted failure. this will add a strength conditioning factor. post workout carbs will aide in your overall conditioning during these two weeks by re-educating the mitochondrial components; thereby, preparing your body for future work and repair.

for the more conditioned athletes, you will want to incorporate proper warmup periods. this should be a two-phase process. first phase should be light cardio prior to activity to increase the HR and raise the core temp of the body. following the cardio, light sets should be incorporated prior to building up to the heavy sets. these light sets will provide for increased blood flow to the muscle, which will - in a sense - prime it for what is to come. after the warmups, i like to do a teir to get to my target weight. lifting too heavy too quickly can easily cause damage to the tendons. get that blood flowing first.

contrary to popular belief, stretching SHOULD NOT be done prior to activity. stretching a cold muscle does nothing to improve flexibility and will actually increase the chance of injury. after the HR and core temp is elevated and the muscles blood flow has been increased thru warmup sets, LIGHT stretching may be incorporated at this time. just remember to NEVER stretch a cold muscle.

outside of this, the load will depend on the overall goal. in terms of motor unit recruitment, the following is a guide for incorporating the appropriate load for the respective goal. these loads must be applied so that the lower end of the rep ranges are achieved with unassisted failure. as the muscles increase in strength, stamina, or endurance, and the higher end of the rep range has been reached, more weight should be added to drop back down to the lower end. this is called the overload training principle.

strength/size: 4-6 reps
strength/stamina: 12-15 reps
endurance/weight-loss: 20-25 reps

(http://www.eroids.com/forum/training-nutrition-diet/workout-exercise/imp...)