*I've gotten to train a lot of people from different ages and backgrounds in the last 8 years. These are just some principles applied to my experience and observations.
Getting stronger is a process that entails working at both mental and physical thresholds both inside and outside the gym on a regular basis. These thresholds are different in each individual context and it is the coach’s job to identify where these thresholds are in line with respective goals. Strength is a product of repetitive, systematic stress that yields positive change in force production, muscular size, coordination, and metabolism (1). These things occur as a result of gradual increases in the demands that elicit them. Appropriate challenges must be applied (at the right times) to elicit positive physical and mental change while avoiding burnout and loss of motivation.
For the beginner, consistency is important for driving initial neuromuscular adaptation so that proper intensity and volume can start being introduced steadily into their program. They need to learn how to move with weight, adapt the movement to their anatomy, and understand how to activate necessary musculature. They also need to learn that their movement will change over time. Inconsistency slows the frequency necessary for these preliminary adaptations. Further, the mental toughness of working through the symptoms of adaptation (e.g., soreness, fatigue, tightness) is not getting trained properly.
Confidence also plays a pivotal role in building the tolerance and capacity to train. Gradual exposure to volume, intensity, and maximal effort in conjunction with good movement progression gets beginners (or mislead intermediates) familiar and comfortable with their thresholds. This gives them confidence in pushing for more progress whether it is more volume (for hypertrophy) or more intensity (force production, explosiveness, speed). The principle of progressive overload is non-negotiable for strength, but it’s the coach’s job to determine the right doses in the right contexts (1).
1) Baechle, Thomas R., Earle, Roger W. Essentials of Strength and Conditioning, 3rd Edition. Champaign, Illinois: Human Kinetics, 2008. Print