People like to complicate weight training more than they need to. You lift weights to build muscular size and strength, that’s it. The largest muscle fibers responsible for gains in strength and size are type IIa and IIx muscle fibers, which make up around 50% of an average person's muscle fibers. These muscle fibers are anaerobic by nature and require heavy resistance exercise to cause overload to the working muscles. Light weight will not provide adequate overload, stimulating mostly the type I muscle fibers. The principle of orderly recruitment states that motor units (a bundle of muscle fibers) are ranked by sized and recruited in ascending order. Type I motor units are recruited first during muscular contraction as they are the smallest motor units. The large type II motor units are recruited sequentially as the movement demands for greater force. Too many trainees train with light weight, doing very little to stress their largest muscle fibers due to the low levels of force. Lifting with light weight only burns calories and provides some endurance work through the stimulation of type I muscle fibers, but does little to build muscular strength and engage the type II fibers. To build muscular size and strength you must lift with the heaviest weight you can handle for the given repetition goal, using perfect form.
The truth is that heavy resistance training intimidates a lot of people for fear of becoming injured. Lifting with heavy weight does not injury trainees, lifting more than you can handle with bad technique injures trainees. Heavy weight is needed to generate the higher levels of muscular force to stimulate the largest motor units. This is hard work; many trainees try to avoid training heavy and find excuses why to reduce the training load on a continuous basis. There are no secrets or ways around working hard, heavy resistance training for the entire body is necessary throughout the year to develop muscular size and strength.
"Legs feed the wolf" and any serious trainee who desires real results must follow suit. In every workout where time or energy is a limiting factor leg training is the first thing to go. Leg training is uncomfortable and extremely demanding which is why many trainees refuse to do it. Many trainees will replace lower body training with running or use the excuse of fear of injury as to why they are handling light weight. Many functional trainers and performances coaches like to avoid these exercises as well. They like to talk about movement patterns, muscle activation and stabilization to build stronger athletes, as if this is more advanced than weight training for strength. This is total BS! If you want real training results you are going to have to train the legs heavy and hard twice per week, once the form is learned. Body weight squats, kettle bells, band walks and plyometric jumps are not going to get the job done. Squats, deadlifts and leg presses done with challenging weight are needed to bring fourth the greatest training stimulus to the lower body. Done through the most complete range of motion as safety dictates, these exercises will bring about the greatest stimulus to the hips, thighs and lower back. These exercises should be rotated each training session as these are the hard exercises with the greatest potential for growth.
Words such as toning, firming and pumping have hurt the weight training community in a big way. Popularized by many of the present-day bodybuilding magazine and fitness models, these words have gotten many trainees spinning their wheels on the wrong exercises. Cable cross overs, concentration curls and hack squats are dominating many commercial gyms. The exercises promoted by old-time strongmen like Mark Berry, Sig Klein and Henry Steinborn have been tossed to the side. The hard-productive exercises have not changed since the early 1900's. Squats, rows, deadlifts, presses, dips, barbell curls and shrugs should be at the forefront of any weight training program. These exercises provide movement of heavy resistance through the fullest range of motion forced by muscular contractions. Two factors needed for productive exercise. All the old-time strongmen knew this and worked religiously at these exercises year after year, with fantastic results! Toners will look for the easier exercises and will make little to no progress. Do not look to replace the most productive exercises, rather formulate your training around them for the best results. Choosing the basic hard exercises is important, but without poundage progression results will be limited.
I have seen plenty of people at gyms training with the same weight they used several years ago. Everyone has a certain weight they are comfortable with on each exercise; however, it is necessary to push past that mental barrier. It is a lack of poundage progression that holds many trainees back whether they notice it or not. Many trainees switch from program to program in hopes of finding the best training routine, inevitably doing little to force poundage progression. Tracking progression, in terms of poundage, is the greatest evidence any individual has of training success. A real assessment needs to be made on your training journal to physically visualize how far you have come since the beginning of your training cycle. The weights must be increased over the weeks, months and years. This is hard to do! It takes patience and discipline to trust in the process and keep grinding away at the basic exercises. It is more appealing to add massive variety, changing the exercise routine every few weeks. Most trainees will run to variety as soon as the weight gets heavy, in fear of reaching a plateau, when they should be digging in and focusing on slowly building the poundage. George Hackenschmidt, an old time strongmen and champion wrestler, used a simple method of progression to build his legendary strength and so can you. Whether you train with single sets, multiple sets or pyramids the overload principles stay the same. Every time you complete the number of repetitions for an exercise add a little iron to the bar for the next workout. A little bit of added weight every few weeks turns into serious weight over the years.
There is no one method for hard weight training. Multiple sets, machine training, low repetitions and olympic lifts all can work given the proper dedication to hard training. The emphasis does not rely on training tools or methods, but rather the principles. Heavy progressive strength training, utilizing the best exercises to cover the full body, will always produce the greatest gains in muscular size and strength. The only question left to ask, are you training hard and heavy?
Resources:
Kenney, W. L., Wilmore, J. H., Costill, D. L., & Wilmore, J. H. (2012). Physiology of sport and exercise. Champaign, IL: Human Kinetics.
Todd, J. S., Shurley, J. P., & Todd, T. C. (2012). Thomas L. DeLorme and the Science of Progressive Resistance Exercise. Journal of Strength and Conditioning Research, 26(11), 2913-2923. doi:10.1519/jsc.0b013e31825adcb4