{
  "slug": "time-under-tension",
  "title": "Time Under Tension Calculator",
  "category": "Strength Training",
  "category_slug": "strength-training",
  "tier": 2,
  "summary": "Compute total time under tension from sets, reps, and a four-digit lifting tempo.",
  "description": "This calculator computes time under tension (TUT) for a resistance-training exercise from sets, reps, and a four-digit tempo. The tempo digits represent seconds spent in each phase of one repetition: eccentric (lowering), pause at the turnaround, concentric (lifting), and pause before the next rep. The tool multiplies per-rep seconds by reps and sets to return total TUT, alongside per-set TUT, per-rep duration, and the tempo written in standard notation. It quantifies duration of loading only; it does not measure or prescribe training stimulus.",
  "page_url": "https://fitmetriclab.com/en/tools/strength-training/time-under-tension/",
  "api_url": "https://fitmetriclab.com/api/tools/time-under-tension.json",
  "formula": {
    "id": "time_under_tension",
    "expression": "\\text{TUT} = s \\times r \\times (t_{ecc} + t_{p1} + t_{con} + t_{p2})",
    "variables": [
      {
        "symbol": "s",
        "description": "Number of sets"
      },
      {
        "symbol": "r",
        "description": "Reps per set"
      },
      {
        "symbol": "t_{ecc}",
        "description": "Eccentric seconds per rep"
      },
      {
        "symbol": "t_{p1}",
        "description": "Bottom-pause seconds per rep"
      },
      {
        "symbol": "t_{con}",
        "description": "Concentric seconds per rep"
      },
      {
        "symbol": "t_{p2}",
        "description": "Top-pause seconds per rep"
      }
    ]
  },
  "inputs": [
    {
      "id": "sets",
      "label": "Sets",
      "type": "number",
      "unit": "sets",
      "default": 3,
      "min": 1,
      "max": 10,
      "step": 1
    },
    {
      "id": "reps",
      "label": "Reps per set",
      "type": "number",
      "unit": "reps",
      "default": 10,
      "min": 1,
      "max": 30,
      "step": 1
    },
    {
      "id": "ecc_s",
      "label": "Eccentric (lowering)",
      "type": "number",
      "unit": "s",
      "default": 3,
      "min": 0,
      "max": 10,
      "step": 1
    },
    {
      "id": "pause1_s",
      "label": "Pause (bottom)",
      "type": "number",
      "unit": "s",
      "default": 0,
      "min": 0,
      "max": 10,
      "step": 1
    },
    {
      "id": "con_s",
      "label": "Concentric (lifting)",
      "type": "number",
      "unit": "s",
      "default": 1,
      "min": 0,
      "max": 10,
      "step": 1
    },
    {
      "id": "pause2_s",
      "label": "Pause (top)",
      "type": "number",
      "unit": "s",
      "default": 0,
      "min": 0,
      "max": 10,
      "step": 1
    }
  ],
  "worked_example": {
    "inputs": {
      "sets": 3,
      "reps": 10,
      "ecc_s": 3,
      "pause1_s": 0,
      "con_s": 1,
      "pause2_s": 0
    },
    "expected_output": "120 s (2:00)"
  },
  "result_summary_template": "{sets} sets of {reps} reps at a {ecc_s}-{pause1_s}-{con_s}-{pause2_s} tempo accumulates {result} of time under tension.",
  "methodology": "Total time under tension = sets × reps × (eccentric + bottom-pause + concentric + top-pause) seconds, with the four phase durations entered as standard four-digit tempo notation (e.g. 3-0-1-0). Per-set TUT = reps × per-rep seconds; per-rep seconds is the sum of the four phases. The result is a duration only; no physiological weighting is applied to the phases.",
  "sources": [
    {
      "label": "Schoenfeld BJ, Ogborn DI, Krieger JW. Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis. Sports Med. 2015;45(4):577–585.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/25601394/"
    },
    {
      "label": "Burd NA, Andrews RJ, West DWD, et al. Muscle time under tension during resistance exercise stimulates differential muscle protein sub-fractional synthetic responses in men. J Physiol. 2012;590(2):351–362.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/22106173/"
    }
  ],
  "faqs": [
    {
      "question": "How do I read a tempo like 3-0-1-0?",
      "answer": "The four digits are seconds per phase in a fixed order: eccentric (lowering), pause at the bottom or stretched position, concentric (lifting), and pause at the top. So 3-0-1-0 means a 3-second lowering phase, no pause, a 1-second lift, and no pause before the next rep—4 seconds per repetition in total. The first digit is always the eccentric even for exercises that begin with the lifting phase, such as pull-ups or rows."
    },
    {
      "question": "Is time under tension the same as training volume?",
      "answer": "No. Volume-load is sets × reps × weight and is measured in kilograms; time under tension is sets × reps × seconds per rep and is measured in time. Three sets of 10 at 100 kg carries 3,000 kg of volume-load at any tempo, while its TUT can range from about 90 seconds to over 300 seconds depending on the tempo digits. The two measures move independently and describe different aspects of a session."
    },
    {
      "question": "What does the X in some written tempos mean?",
      "answer": "Coaches sometimes write an X in the concentric position—for example 3-0-X-0—to indicate the lift is performed with maximal intended speed rather than to a count. An explosive concentric still takes real time, typically around a second on compound barbell lifts, so entering 1 in the concentric field is a common way to represent an X tempo in this calculator. The arithmetic treats it like any other entered duration."
    },
    {
      "question": "Does a paused second count the same as a moving second?",
      "answer": "In this calculation, yes—every second of the four phases is summed equally. Physiologically the phases are not equivalent: a pause at a supported lockout position loads the muscle far less than a second spent mid-range under the eccentric, and force output differs between lowering and lifting at the same speed. TUT is a bookkeeping total of duration, and two sessions with identical TUT can involve different amounts of muscular work."
    },
    {
      "question": "Is there an established target for time under tension?",
      "answer": "No single target is established in the research. Commonly discussed per-set figures in coaching literature cluster around 20 to 70 seconds, but comparative studies and the 2015 Schoenfeld meta-analysis found broadly similar hypertrophy outcomes across a wide range of repetition durations when sets approached failure. The calculator reports the duration produced by the entered tempo and leaves interpretation to the user and their coach."
    }
  ],
  "related_tools": [
    {
      "slug": "volume-load",
      "title": "Training Volume Load Calculator",
      "api_url": "https://fitmetriclab.com/api/tools/volume-load.json",
      "page_url": "https://fitmetriclab.com/en/tools/strength-training/volume-load/"
    },
    {
      "slug": "rest-time",
      "title": "Rest Time Between Sets Calculator",
      "api_url": "https://fitmetriclab.com/api/tools/rest-time.json",
      "page_url": "https://fitmetriclab.com/en/tools/timing-pacing/rest-time/"
    },
    {
      "slug": "workout-duration",
      "title": "Workout Duration Calculator",
      "api_url": "https://fitmetriclab.com/api/tools/workout-duration.json",
      "page_url": "https://fitmetriclab.com/en/tools/timing-pacing/workout-duration/"
    }
  ],
  "last_updated": "2026-08-08",
  "price": {
    "value": 0,
    "currency": "USD"
  },
  "runs_in_browser": true,
  "disclaimer": "Educational estimate produced from a published formula. Not medical, nutritional, or training advice. Calculations are deterministic — apply the formula to the inputs to reproduce the result."
}