Exercises: Main and Assistance, What’s the Difference?

by Joe Giandonato, MBA, MS, CSCS

The construct of a strength training program hinges on the competitive goals and needs of an athlete. For strength athletes, a greater emphasis is placed on the incorporation and implementation of movements which enhance the performance of meet or event lifts. Powerlifters, both raw and equipped, integrate movements to improve their performance on the big three – squat, bench, and deadlift. Olympic weightlifters utilize a variety of squat, deadlift, and overhead movement variations to drive up their numbers on the clean and jerk and snatch. Strongman competitors will incorporate specialized movements to replicate events or to improve upon deficiencies encountered during event training and competition. Ultimately, strength athletes need to perform movements outside of their events to collectively improve performance, ward off injuries, and maintain longevity in their chosen sport.
Main Lifts
The events that a strength athlete will be judged or tested on will constitute as a main lift or event. These movements usually take precedence over other work performed within a program or single session. A great amount of energy and focus needs to be devoted to these movements to improve the technical and mental aspects of the lift. Main lifts also entail the component of specificity. For example, a full meet powerlifter won’t get better at squatting if they don’t squat. Similarly, a weightlifter won’t get better at snatching, unless they practice the movement in the first place. If a training program or single session were a meal, the main lifts would the main entree. On the other hand, assistance movements, which include supplementary and accessory exercises, could be considered the meal’s appetizer and the ever necessary post meal stick of gum or dinner mint.
Supplementary Lifts
Movements that are considered supplementary are exercises that share biomechanical similarities to main lifts. A non-exhaustive list of supplementary lifts for a Powerlifting and Olympic Weightlifting events will be provided below.
Squat: dead squat, pause squat, box squat, Olympic squat, squat against pins, isometric holds and walkouts, and squats performed with variable resistance, such as bands, chains, and weight releasers
Bench Press: close grip bench press, dead bench, paused bench press, board presses, floor press, isometric holds, incline bench press, and bench presses performed with variable resistance, such as bands, chains, and weight releasers
Deadlift: Romanian deadlift, rack pull, block pulls, paused deadlift, snatch grip deadlift, deficit deadlift, double over hand deadlift, and deadlifts performed with variable resistance, such as bands, chains, and weight releasers
Olympic Weightlifting
Clean and Jerk: push jerk, split jerk, front squats, clean pulls, Romanian deadlifts
Snatch: snatch grip deadlifts, snatch pulls, overhead squat
The performance of these movements should be closely analyzed and tabs should be kept on frequency, volume, intensity, and tonnage as well as recovery. These lifts have a greater correspondence to the main lifts in terms of their execution and often times require they be performed with comparable loads and focus. While supplementary movements are not main lifts and usually do not carry an equal degree of technical precision, you can become overtrained quite easily if you are not careful. Supplementary exercises which are conducted at higher velocities and/or with significantly heavy loads should not be performed to failure in order reduce the likelihood for injury, the adoption of faulty motor engrams, and to spare the central nervous system. 
Accessory Lifts
Accessory movements typically comprise exercises which do not require high loads or technical precision and do not share many biomechanical similarities to main lifts or events. Often times, accessory movements are those that fill in the gaps that training may create, and usually include: corrective exercises, unilateral exercises, single joint movements, or machine based exercises.
For instance, if a lifter demonstrates knee valgus during squats, they might include clamshells, lateral lunges, or seated banded abductions into their program to strengthen the glute medius. A powerlifter wanting to move up to a heavier weight class may consider adding more hypertrophy based training within their program, consisting of presses and rows. A deadlifter struggling with their lockout strength may want to include pull throughs and glute bridges. 
Many novice and intermediate strength athletes and new coaches miss the mark by failing to understand the symbiotic relationship among main, supplementary, and accessory exercises. Each movement performed will render an impact, whether immediate or residual on another one, and if special attention is not given to program design, then negative effects may result. Before supplementary and assistance movements are to be prescribed within a program, a needs analysis needs to be conducted.
As a strength coach, personal trainer, and strength athlete, I am always assessing my athletes, clients, and myself and am conducting a running needs analysis as strength, girth and resultant strokes are ever changing during the course of a long-term program. As such, the inclusion of assistance work needs to support the performance of the main lifts and maintain musculoskeletal health. Its programming and implementation depend on a host of factors and need not be haphazardly tossed in alongside the main lifts.
Assistance Tips
• Avoid training to failure on supplementary exercises.
• Sessions should be structured with a majority of energy and focus being devoted to main lifts. 
• Accessory movements may be performed as corrective exercises during the warm up, as mobility fillers during the workout or as unilateral or single joint exercises at the end of the workout. 
• Pick your battles wisely. While performance of each movement should be recorded and tracked, going for broke on assistance exercises can potentially interfere with performance on main lifts. On accessory movements and certain supplemental movements, improvements in load are relative since they are performed with less external loads.
• Assistance exercises may be performed on a separate day of the week