Exercise variables

Any training program must continually progress over time in order to continue achieving results. Equally, a single workout must account for specific training variables which, when added together, account for the progression of the overall training program. The design of a single workout routine will absolutely affect the overall result of the workout program as a whole. For example, a workout program consisting of four workout routines, one of which is poorly designed, will achieve a lesser result than one with four properly designed routines.

When designing a workout routine, training variables must be properly applied to achieve the intended goal, whether the goal is physique, power, strength, endurance, or all of the above. This is why it is ill-advised to randomly choose a few exercises (or to use a deck of “exercise cards”) to create a workout routine. While a single workout conducted this way will fatigue the muscles, there is no end goal in the design. Therefore, the overall program will result in little or no progress in fitness other than a few calories burned.

Every workout routine should be composed of at least six training variables: choice of exercises, order of exercises, number of sets, amount and type of resistance, rest taken between sets, and training frequency. These variables should be carefully chosen so as to progress in a healthy way without injury or over-training while achieving the desired results.

Choice of Exercises

Individual exercises are designed to work specific muscles or muscle groups. Exercises must be chosen that work the desired muscle group for a program to be effective. It sounds really simple, and it is, but too often people will decide they want bigger arms and then proceed to do various biceps curls while completely ignoring the triceps, forearms, and shoulders that contribute overall arm size. Or they spend time in the gym doing nothing but bench presses and wonder why they don’t get “ripped” or “shredded”.

There are two types of exercises: primary exercises and assistance exercises. Primary exercises are specific to a goal, such as “getting bigger arms”. Assistance exercises support the goal of primary exercises, such as working the core so you can lift heavier weights with your arms. Primary exercises are usually big muscle movements involving multiple joints: clean, deadlift, squat, press, row, etc. Assistance exercises are usually single joint exercises: biceps curl, triceps extension, fly, calf raise, crunch, etc., and typically involve less resistance due to the use of fewer muscles in the movement.

Order of Exercises.

In general, exercises should be ordered from the larger muscle groups (such as legs and back) to the smaller muscle groups (such as biceps and shoulders), and from the most intense to the least intense.

The order of exercises directly contributes to the adaptations made and the effectiveness of the program to achieve the desired results. As a workout routine progresses, the lifter will have less and less energy to perform the exercises. Big, primary movements take more energy than smaller, isolated movements. If a fully-body workout is being performed, then the most important exercises based on the goals of the lifter should be performed first.

Number of Sets

Different people have different levels of fitness. By tuning the number of sets, the intensity of a workout can be adjusted to meet a lifter’s current fitness level while progressing toward their goal. One set of an exercise may be used to maintain current fitness levels, while multiple sets of an exercise should be used to progress in fitness level. Care must be taken that not too many sets are performed during a single workout routine, particularly when intensity is high, in order to avoid injury or over-training.

Proper accounting for sets includes the number of sets performed per exercise, the number of sets performed per muscle group, and the number of total sets in a workout routine. There are typically three to six sets performed per exercise depending on the goal. However, a person training to lift very heavy weight may perform 12 sets of a given exercise, but complete only two repetitions per set.


The amount of resistance used in a set is inversely related to the number of repetitions performed. That is, the heavier the weight, the less repetitions a lifter can perform before reaching muscle failure. Resistance is often measured in repetition maximums (RM). For example, how many repetitions can be performed with a given weight before reaching muscle failure. Or, what weight can a lifter use to reach failure and 10 repetitions. This weight amount would be the lifter’s 10RM. Testing a lifter’s 1RM and 10RM often will provide an idea of the progress in their level of strength and if their current program of effective.

Working within certain repetition ranges will provide different results. To gain strength, a lifter should focus on lifter heavy weights for two to six repetitions. For hypertrophy, a lifter should stay within the eight to 12 repetition range. For muscular endurance, focus on lifting in the 18 to 25 repetition range.

Another factor to be considered under resistance is time under tension. This refers to how fast or slow a weight is being moved. More time under tension equates to more hypertrophy, while fast movements equate to power. If a lifter’s 1RM on the biceps curl is 45lbs, then performing several fast repetitions with a 20lbs weight will emphasize power and have little effect on hypertrophy.

Like the other training variables, rest period depends on the lifter’s goals. In general, the higher the resistance or intensity and the lower the rep count, the longer the rest period should be. This is typically how a lifter trains when the goal is strength or power.

Rest Period

Rep MaxRest Period
55 min.
5-73-5 min.
8-102-3 min.
11-131-2 min.
14+1 min

When the goal is hypertrophy, shorter rest periods support greater gains and faster progression. This is because muscle fatigue is believed to play a role in muscle growth and development. As repetitions increase the muscles fill with lactate which may provide additional energy to the muscle. Endurance athletes tend to use low resistance and high repetitions with rest periods of less than one minute in order to achieve the same level of fatigue.

Circuit training and some type of set training, such as super-sets, compound-sets, and tri-sets, use rest periods strategically in order to tax the body’s energy systems and fatigue groups of muscles in a particular sequence. In addition, some programs use “active rest periods” where the lifter performs some kind of isometric exercise to work an antagonist or opposing muscle group while the worked muscle group rests.

Training Frequency

While rest periods deal specifically with how much rest is taken between sets, frequency deals with the amount of recovery time the worked muscles get between training days. In general, a lifter should only work a given muscle group every two to seven days depending on their goals. There are exceptions, of course, but over-training should be avoided to prevent injury. In addition, muscles will not grow and strengthen without proper rest. Strategically, frequency and rest/recovery of muscle groups is just as important as exercising them.

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