The problem with generic zone models
Most swim analysis tools ship with a default energy-system model: five zones, roughly matched to percentages of threshold pace, built from a textbook that isn't yours. If your program is built on a different structure — different zone names, different rest ratios, a different way of calculating pace bases — a generic model will mislabel your sets. A threshold set in your system gets read as aerobic. A descend set built around best-time percentages gets flattened into someone else's five-zone chart.
This isn't a small annoyance. If you've spent years tuning a system — how you name zones, how you set pace bases, how you build rest into a set — you want a tool that respects that system, not one that overwrites it with a stock model.
What "your philosophy" actually is, in concrete terms
Before any tool can follow your system, you need to be able to write it down. Most coaching philosophies reduce to four components:
- Zone definitions. What do you call your zones, and what's the pace or heart-rate band for each? Example: Aerobic (CSS + 8 to CSS + 15 per 100), Threshold (CSS − 2 to CSS + 3), VO2 (CSS − 4 to CSS − 8), Sprint (max effort, no pace target).
- Pace basis. Do you build zones off CSS (critical swim speed from a 400/200 time trial), off a T30, off best times at race distance, or off a recent taper-meet swim? A system built on CSS handles distance swimmers differently than one built on 100/200 best-time percentages for sprinters.
- Rest ratios. Every coach has a rule of thumb. Some run aerobic work at :10–15 rest per 100, threshold at :20–30, VO2 at 1:1 work-to-rest or longer. If your tool doesn't know your ratios, it can't tell an aerobic set from a threshold set just by looking at the interval.
- Set-construction rules. Do you always build main sets in descending broken pieces? Do you cap sprint work at 25s and 50s only? Do you never put VO2 work behind a hard breaststroke kick set? These are structural rules, not just paces, and they're part of the philosophy too.
If you can write these four things down on one page, you have something a tool — or an assistant coach — can actually follow.
Building a spec sheet you can hand to any system
Write it like you'd write it for a new assistant coach who's never seen your program. Concrete example, distance-based CSS system:
- CSS from 400/200 time trial: 400 in 5:00, 200 in 2:16. CSS = (400 − 200) time ÷ (400 − 200) distance = 164 sec ÷ 200 m = 0.82 sec/m = 1:22/100.
- Aerobic: 1:30–1:37/100, rest :10–15 per 100.
- Threshold (CSS): 1:20–1:25/100, rest :20–30 per 100, sets 400–1500m broken into repeats of 100–400.
- VO2: 1:14–1:18/100, rest equal to or greater than work interval, repeats capped at 200m.
- Sprint: max effort only, full recovery (2:00+), repeats capped at 50m.
A sprint-oriented system looks completely different — zones built off percentage of best 50/100 time, shorter rest even at high intensity because the philosophy prioritizes repeatability over full recovery. Neither is wrong. But a tool that assumes one universal model will misread whichever one you don't happen to use.
What to check before you trust a tool with your system
When you're evaluating any workout-analysis tool, ask these questions directly:
- Can it take your zone names and pace bases as input, not just its own default five zones?
- Can it recalculate zones from your own time trial data rather than a population-average formula?
- Does it let you flag structural rules — no back-to-back VO2 days, sprint work capped at 50m — so its read of a week's training reflects your actual program design, not a generic taper curve?
- Does it show its work? You want to see why it labeled a set as threshold, not just the label. If the pace math is hidden, you can't correct it when it's wrong.
If a tool can't take input beyond a workout description, it's not analyzing your system. It's translating your sets into its own, which defeats the purpose.
Keep a copy outside any app
Whatever tool you use this season, keep your spec sheet as a standalone document — a page in your coaching binder or a shared doc with your staff. Systems and tools change. Your training philosophy shouldn't have to be rebuilt from memory every time you switch software, and a new assistant coach should be able to read one page and run a practice the way you'd run it.
SwimIQ lets you set your own zone definitions and pace basis — CSS, best-time percentage, or your own thresholds — so a set gets analyzed against your system instead of a generic model, and you can see the pace math behind every zone call it makes.