Anthony P. Bruno

This guide is a compilation of Acute Exercise Variables taken from several peer-reviewed texts and world-renowned strength experts.  Because the research shows some variation in the exact number that is best in each of the above columns, the goal is to simplify all of the information. The numbers given are examples of common starting points. It must be known that each of these variables can be manipulated. And in manipulating one or more of the variables, one can expect an altered outcome.  The above outline will save you time and frustration, especially when you go from training a high school football player with one year of weight training experience to the next client that has ten years of weight training experience but lacks muscle endurance or joint stability.

Training age refers to the amount of experience the athlete/client has performing a specific type of exercise or movement. If someone has been training less than one year, they obviously should not be doing maximum lifts.

Load or resistance comes in many forms; free weights, rubber bands, body weight, machines, water, etc. It is possible to use a load over 100 of your maximum when performing eccentric reps with a spotter or a machine. Eccentric strength can be up to 40% greater then concentric⁷. (The amount of resistance or the % of your maximum.)

Repetitions dictate all other variables. If my goal is 10 reps, then I'm working with approx. 75% of my maximum. If I perform 20 reps, then my body's long term adaptation will be an increase in muscular endurance. Can you see how this works? If you think of reps like this it may change your view, think of how many reps you can finish at complete failure of the set. Choose your goal and then the number of reps you should be completing to obtain the specific adaptation to training.

Time Under Tension is the amount of time needed to perform the exercise or movement in order to get the desired outcome. You obviously can't do 60 seconds of work with 95% of your maximum, nor would it be beneficial to do 10 seconds of work with 60% of your maximum. Each of these columns is both interrelated and somewhat flexible because individuals can react slightly different to the same stimulus. Ian King and Charles Poliquin come to mind when referencing time under tension.⁵ Reps and sets mean nothing unless the work being done “TUT” is sufficient to cause a specific outcome.

Tempo is the speed at which you perform a movement or exercise. Following Ian King's formula⁵, the eccentric number is first, then an isometric hold (if any), then the concentric number, all given in seconds.  The outcome can be manipulated by changing the tempo. (AFAP=Movement as fast as possible, some authors (Poliquin and Chek) use an 'x' to represent AFAP). Tempo has great relevance when it comes to sport-specific conditioning, since the speed you perform at should be the speed you train at.

Volume - Total workout time x reps x range of movement or distance per unit of time. Volume = total work completed. Volume can also mean total weight moved one time. ² Volume, intensity, and periodization are…

Intensity - Combination of load, velocity as in speed of movement (time under tension), rest period.

Sets -

Rest -

Adaptation -

Motor Unit Recruitment -

Dominant energy system (degree of fatigue) is affected by Intensity (Load), Duration (Time Under Tension), number of Repetitions, Order of Exercise, and Energy Storage Capacity (blood oxygen levels, muscle & liver glycogen levels, lung capacity, lactate threshold, enzymes, etc.) which may vary from day to day. Therefore these numbers are by no means fixed.^2,7

Energy from all three systems is always being used. What changes is the percentage from each, in turn, the acute variables tell us which energy system is dominant and for how long.

As you can see, each category above relies closely on the category next to it. Program design should be a scientific process towards one or more adaptations to training.

	Acute Exercise Variables						Adaptation
			TIME
TRAINING			UNDER						ENERGY
AGE4,5	LOAD %	REPS 2	TENSION	TEMPO	SETS3	REST	OUTCOME2,5	FIBER TYPE2,7	SYSTEMS7
Advanced	100+	ECC Only	Varies	Slow	1-2 Sets	>3-5 m.
	100	1	1 to 5 s	AFAP	5+	3 - 5 m.	Neuromuscular	FF     FT  g   Type IIB	ATP/PC
2+ yrs	95	2	5 to 10 s		5+	3 - 5 m.	Adaptation	Fast Contract & Fatigue	PHOSPHAGEN SYSTEM
	90	3	10 to 20 s	1  0  1	4 - 5	3 - 5 m.			NON-OXIDATIVE
	85	5	10 to 20 s		4 - 5	2 - 3 m.	Strength	FI	GLYCOLOSIS
1-2 yrs	80	7	20 to 60 s	2  0  2	3 - 4	2 - 3 m.		Intermediate Fatigue
	75	10	20 to 60 s		3 - 4	2 - 3 m.	Hypertrophy		LACTIC ACID SYSTEM
	70	12	60 to 80 s	3  0  3	3 - 4	1 - 2 m.		FR     TypeIIA
	65	15	60 to 80 s		2 - 3	1 - 2 m.		Fatigue Resistance	OXIDATIVE
1st 6 mos.	60	19	80 to 150 s	1  1  2	2 - 3	1 - 2 m.	Muscular Endurance		GLYCOLOSIS
	55	24	80 to 150 s		1 - 2	30 s.- 1 m.		ST     Type I
	50	30	+ 2.5 min	3  1  3	1 - 2	30 s.- 1 m.	Cellular Adaptation	Slow Fatigue	AEROBIC SYSTEM
HOW TO USE THIS INFORMATION
	1.  Choose a goal in the Outcome column (i.e.: muscular endurance).
	2.  Move left to the Repetition column (if muscular endurance is your goal, repetitions should be approx. +/-19).
	3.  Move right to the Time Under Tension column (when your goal is to increase muscular endurance, then your
	time under tension should be between 60-150 seconds).
	4.  Move right to the Tempo column (will you use an isometric hold, a slow eccentric and fast concentric, or the opposite?)
	The numbers given in the tempo column are examples of what could be used.
	5.  Move right to the Sets column (when your repetitions are between +/-19, then your sets are 2-3).
	6.  Move right to the Rest column (if you are working for 1-2 minutes, then you should rest 1-2 minutes in between sets).
	(When training for muscular endurance, this is the only time your work to rest ratio is equal.)

This graph can be used by strength coaches, trainers, therapists, and clients alike. It can be a great quick reference when someone wants to change their program but does not want to change the outcome. (ie: My client is bored with 6 second reps but they want to continue working in the hypertrophy phase, what else can I have them do?)  It can be used to properly periodize clients… whether they are athletes or personal training clients. Periodization training has been proven better than non-periodization training.

Feel free to make copies of the table for yourself and your clients. Because this is not a prescription (it is a reference for prescription) the following items are taken for granted but not to be forgotten: type of exercise, frequency, periodization style, range of motion, progressive overload, peaking, tapering, total volume, etc.