What is an Ergometer?

Ergometer, erg, indoor rower: same thing

The three terms describe the same machine. "Ergometer" is the technical name (from Greek ergon, meaning work) and gets used in coaching and physiology contexts. "Erg" is the everyday short form rowers use - "we did 60 minutes on the erg" or "her 2k erg is 7:15". "Indoor rower" or "rowing machine" is what the wider fitness market calls it. They all refer to the same piece of kit: a sliding seat, a footplate, a handle on a chain, and a flywheel that resists the pull.

How an ergometer works

Every stroke pulls the handle, which spins the flywheel. The flywheel meets resistance from air (Concept2), water (WaterRower), magnets (Hydrow), or a combination. Sensors measure how fast the flywheel decelerates between strokes, calculate the work done, and convert it into metres rowed. The monitor displays this conversion in real time as split, watts, distance and calories.

On a Concept2, the resistance you feel comes from the damper lever on the side of the flywheel cage - settings 1 (low resistance, fast acceleration) to 10 (high resistance, slow acceleration). The damper changes the feel of the stroke but not the score. What matters for performance is the drag factor, which the monitor measures in the More Options menu and adjusts for damper position and air density. Use the erg pace calculator to convert any split into watts, calories and predicted race times.

The Concept2 standard

The Concept2 RowErg (formerly Model D and Model E) has been the dominant ergometer in rowing since the mid-1980s. It is the machine used at the World Rowing Indoor Championships, the C.R.A.S.H.-B Sprints in Boston, the British Indoor Rowing Championships, the Australian Indoor Rowing Championships and almost every national federation's testing protocol. Its longevity comes from a simple, repairable design and a calibration that has stayed consistent for decades, which lets coaches compare scores across years and between athletes anywhere in the world.

Other manufacturers (WaterRower, Hydrow, NordicTrack, Echelon) make rowing machines for the home fitness market, but they do not standardise to the Concept2's calibration. A 2k personal best on a WaterRower is not directly comparable to a 2k personal best on a Concept2.

What the readouts mean

• 500m split: the time it would take to row 500m at the current pace. A 1:45 split means you would cover 500m in 1 minute 45 seconds. This is the primary pacing metric in rowing.
• Watts: instantaneous power output. Concept2 uses watts = 2.80 / (split_seconds / 500)^3. A 1:45 split is roughly 268 watts; a 1:30 split is roughly 425 watts.
• Calories per hour: approximately watts x 4 plus 300 for basal metabolism. Useful for fitness tracking but not a precise measure of exertion.
• Stroke rate: strokes per minute. UT2 (low aerobic) sits at 18 to 20, UT1 at 20 to 24, threshold at 26 to 28, race pace at 32 to 38.
• Distance: metres of work, calculated from flywheel deceleration, not literal distance.

How rowing clubs use ergometers

The erg has three main jobs in a rowing club. First, it lets the squad train when the river is unsafe or unavailable - cold, dark, flooded, frozen or simply when the boats are out for maintenance. Second, it gives coaches a controlled environment to measure individual fitness through documented tests (the 2k, the 5k, the 30-minute and the 60-minute are the standard pieces). Third, it forms part of crew selection alongside seat-racing and on-water assessment.

Erg scores feed into the squad management system. Recording every test, tracking improvements over time, and comparing rowers against age and weight standards is the kind of data work that makes selection decisions defensible. Row HQ's coach tools store erg scores against each rower's profile so coaches can see fitness trajectory across a season.

Erg testing protocols

Standard ergometer test pieces in competitive rowing:

• 2,000m (2k): the gold-standard fitness test, mirroring the Olympic race distance. Maximum effort, typically 6 to 8 minutes for elite men, 7 to 9 minutes for elite women.
• 5,000m (5k): aerobic test, 17 to 22 minutes for most senior rowers.
• 30 minutes: distance covered in 30 minutes at sustainable threshold pace. Used to gauge endurance.
• 60 minutes: longer aerobic test, typically rowed at UT1 or UT2 pace.
• 4 x 2,000m or 8 x 500m intervals: race-specific power and recovery testing.

Each protocol is logged with the rower's body weight at test (lighter rowers face a power-to-weight disadvantage that the World Rowing weight-adjusted formula corrects for) and the drag factor used.

Indoor rowing as a sport in its own right

Indoor rowing has grown into a competitive sport beyond its origins as a boat-rower's training tool. The C.R.A.S.H.-B Sprints in Boston (since 1982) is the original indoor 2k championship and still draws over 2,000 entries a year. The British Indoor Rowing Championships at Lee Valley, the European Indoor Rowing Championships, and the World Rowing Indoor Championships now run alongside Concept2's online challenges and the regional indoor circuits. Many CrossFit boxes and gyms run their own ergometer leagues, broadening participation well beyond traditional rowing clubs.