Different training goals need the bar to move at different speeds. Lifting heavy and slow builds maximal strength; lifting lighter and faster builds power. Training zones are speed bands that tell you which quality you're actually training in a given set.

Output uses four zones, shown heaviest first:

Because Output knows how fast you move a given weight, it can work backwards and tell you roughly which weights will land you in each zone. That's the weight range shown beside each one.

This is personal to you. Two athletes with the same 1RM can have different ranges, because they don't move the same weight at the same speed.

These ranges come from your most recent velocity profile, and are rounded to the nearest whole kilogram or pound.

For the faster zones, the calculated weight can come out lighter than an empty barbell. Rather than show a figure you can't actually load, Output caps the display at 20 kg (or 45 lb), the weight of a standard bar.

So a zone might read 20 – 50 kg, or simply < 20 kg if the whole range falls below an empty bar. That's normal, and usually means you'd need to move an unloaded bar very fast to hit those speeds.

Underneath the ranges you'll see the share of your sets that fell into each zone over the last three months. This is a useful reality check — it's easy to believe you've been training for power while most of your sets have quietly sat in the strength zones.

Each set is placed using its best mean velocity. If a set was performed at a speed outside the zone it was assigned to, it's counted in whichever zone its speed is closest to, so the breakdown reflects how you actually lifted rather than what was planned.

All variations of the exercise are combined into the one breakdown.

A zone may show a change, such as +4 kg. This means the weight you'd need to lift to train in that zone has gone up — usually a good sign, since it takes more weight to slow you down.

It compares your most recent velocity profile against the earliest one from the last three months — the same window as the set breakdown above. Unlike the trend charts elsewhere in the app, nothing on this widget has a date range selector, so three months is the only period it reports on.

It only appears when you have two separate profiles within those three months.

Without sensor data there's nothing to calculate personal ranges from, so the zones are shown with the percentage of your 1RM that each one typically corresponds to. That gives you a starting point to work from.

Once you've lifted with the Output sensor across a few different weights, the zones fill in with ranges specific to you.

See also: Estimated 1RM Ranges