How We Use Time Under Tension
TIME UNDER TENSION (TUT)
Time under tension is used as the unit of measurement which a muscle is put under tension for a set time to elicit a specific metabolic response & physical adaptation. We use tempo work and rep ranges to monitor our TUT for different exercises. Below is a breakdown of each strength/structural rep scheme on the strength-speed & endurance continuum.
RELATIVE STRENGTH [ Neural Recovery Zone - 0-10 seconds - 1-2 reps] [ ATP-CP Recovery Zone - 10-20 seconds 2-5 reps]
Relative strength is trained between 1-5 repetitions and a TUT of less than 20 seconds with the emphasis being on the athlete lifting heavier loads (70-80%+ of 1RM). The goal is to make the body more efficient at lifting heavier weights by adaptations in the nervous system [CNS].
Longer rest periods up to 2-3mins + are often used between sets to allow the body to work at a higher intensity combined with a higher number of sets per exercise. Lowering the rest interval can be important for fitness adaptations and absolute strength-endurance or strength endurance adaptations.
Training lower reps at higher loads can be highly beneficial for intermediate and advanced athletes who have gained the ability to produce ‘power’ in their training. This strength zone should be used once you have built the right bases of support and structural balance upon the other strength zones.
Lower reps/higher load will cause a higher strain on the CNS. This will of course be based on the athlete’s ability to produce force/power production, ability to express power with those movements selected, and their recovery between high CNS output training based sessions.
FUNCTIONAL HYPERTROPHY [ 20-40 seconds - 5-8 reps]
Functional Hypertrophy uses repetition ranges of 5-8 with a TUT of 20-40 seconds. This mixture of strength and hypertrophy, i.e. muscle growth, allows the body to become stronger and build muscle at the same time.
Rest times of 2-3mins and less sets are required than training strength. This style of training can add muscle that has function and performance, and is an important cross-section for fitness gains.
HYPERTROPHY [ 40-70 seconds - 8-12 reps]
Hypertrophy (8-12 reps), at 40-70 seconds of tension, allow the body to be under tension long enough to begin to sync up the CNS and musculature, build muscle (providing nutrition is sufficient), and achieve improved movement quality. Lifting a weight for this amount of time can result in DOMS (delayed onset muscle soreness), following your workout and and is beneficial for individuals wanting to gain muscle or having a toned and defined look. Rest periods are generally between 60-180 secs.
ENDURANCE [ 60 sec -120 sec - high rep]
Endurance training uses repetition ranges from 12+ reps) with a time under tension of 60-120 seconds trains the aerobic system and results in glycogen depletion, minimal rest periods (10-90s) are needed for recovery and lighter loads. This is beneficial as we take exercises that have been performed proficiently and are able to be integrated into conditioning.
There are four stages to tempo training (Eccentric, Isometric, Concentric, Isometric), and these numbers represent each of the four stages and the time required to complete the movement.
Here’s how to interpret these numbers:
We use a four digit system to explain tempos when prescribed in exercises to help direct training stimulus & dose response.
The first number represents the eccentric or concentric phase against gravity.
The second number represents the isometric pause in the end range of motion
The third number represents the concentric or eccentric phase against gravity.
The fourth and final number represents the isometric pause at the end of the rep.
BELOW ARE SOME EXAMPLES OF VARIOUS TEMPOS:
Here is how we write tempo work here at CrossFit Fargo
Back Squat @ 32X0 Tempo: 3sec lower, 2sec pause at bottom, X (explosive) drive upwards and no pause at the top.
Chin up @ X331 Tempo: explosive pull up, 3sec pause at top, 3 sec lower, 1 sec pause at bottom
Strict Press @ X301 Tempo: explosive press up, 3 sec pause at top, normal lower down, 1 sec pause at shoulder