Neuroendocrine refers to interactions between the nervous system and the endocrine system. Muscle growth and strength increase largely depend on the neuroendocrine adaptations and acute responses evoked during exercise.
Unfortunately, one of the critical elements missing from isolation ‘weight-training’ movements (ex. bicep curls) is they invoke essentially no Neuroendocrine response.
A vital hormonal response to athletic development is a substantial testosterone increase, along with an insulin-like growth factor and human growth hormone. Exercising with protocols known to elevate these hormones eerily mimics the hormonal changes sought in exogenous hormonal therapy (steroid use). Training Programs that induce a high neuroendocrine response produce top tier athletes. Increased muscle mass and bone density are just two of many adaptive responses to exercises capable of producing a significant Neuro. response.
A starting point recommended for Weightlifting would be mastering Powerlifting
(the sport of three lifts: the Bench Press, Squat and Deadlift), to be followed later by the more dynamic Clean & Jerk and the Snatch. Being not only demanding of precision and athleticism, but these multi-joint compounds also elicit a profound Neuroendocrine response, emphasizing constant engagement of midline, working core to extremities.
Simply put, in order to maximize neuroendocrine response, focus on working large muscle groups before smaller muscle groups. Use higher volume and moderate to high intensity with shorter rest intervals between sets.
If you are not an avid Olympic Weightlifter, activate a higher Neuro response by programming your smaller muscle groups with your largest muscle groups. (ex. Superset your bicep curls with deadlifts, your tricep extensions with bench press, shoulder laterals with squats). Recruit an even larger response by incorporating Compound movements (ex. a front squat with an overhead press, a sumo deadlift with an upright row, a back squat with a wide grip behind the neck Press).
Maximize your natural growth hormone by recruiting more muscle fibers, more quickly, and more intensely.
Most athletes respond best to a high frequency and high volume of Weightlifting and perform best when not handling maximum poundages at each session.
The Heavy-Light-Medium training system gives the athlete the volume and frequency that they need to drive progress, and ensure ongoing success while allowing enough recovery for one heavy day each week for maximum output. The benefit that this program has for athletes cannot be overstated. Non-barbell sports athletes must balance training for their sport and training in the weight room. Most sports are demanding of the lower body and many athletes will not have enough reserves in their tank to squat heavy more than once per week. The HLM system allows the athlete to place their heavy squat day on the day of the week that allows them to train in their most recovered state. During the rest of the week, the athletes will have to perform strength workouts in a state of fatigue. The HLM system makes this a little easier to manage. On the light and medium days, the athlete will be focusing on form and technique, and speed.
As a starting point though, start your light day 10-20% lower than your heavy day, and set your medium day 5-10% less than your heavy day.