The organizer's guide · 12 min read
How to run an efficient HYROX simulation.
From chaos to flow — the one thing that decides whether your race day runs smoothly is heat planning.
Organizing a HYROX simulation is easier than most people think — but there's one thing that decides whether the day flows or turns into chaos: heat planning. That is, how many athletes you start, how often, and in what order they move through the stations.
Get it right and the race feels like a real event: athletes move smoothly, nobody stands around waiting, and the energy stays up all day. Get it wrong and queues build at the sled, people crowd the rowers, and a race that should take two hours drags out to four.
This guide walks you through how to plan a sim that flows — whether it's your first or your twentieth.
The most common mistakes first-time organizers make
- Too many in the same heat. You want to get everyone through quickly, so you start 15 people at once — but your box maybe only has 2 SkiErgs and one sled lane. Result: a queue right at the first station.
- Starts too close together. If you start a new athlete every two minutes but each station takes four, the queues never clear — they grow all day.
- Planning around the run instead of the bottleneck. The run is rarely the problem in a gym sim; it's the stations with limited equipment that set the pace.
- No buffer for different levels. An experienced athlete and a first-timer can finish 30+ minutes apart. Without some slack in the plan, the fast one catches up to the slower one in front.
- Manual timing that can't keep up. You think "we'll take the times by hand" — then realize mid-race that keeping track of 40 people with pen and stopwatch is impossible.
The bottleneck stations — what governs the whole flow
The key insight: your start interval is set by your tightest station, not by the run.
In a gym sim you usually have a limited number of the heavy equipment pieces. The most common bottlenecks:
- Sled (push/pull) — takes up space, needs dedicated lanes, and most boxes only have a handful. Often the absolute bottleneck.
- SkiErg and rower — limited number of machines. If you have 2 SkiErgs, only 2 people can go at once.
- The run — in a box it's often done as laps indoors or outside. Rarely a bottleneck, but worth considering if the space is tight.
The basic rule: work out how long one athlete blocks your tightest station. If you start a new athlete at roughly that interval, station A becomes free just as the next person arrives. No queue forms.
How to work out the optimal number of athletes per start time
Two dials control everything: how many per heat and how often you start.
Say you have 4 sled lanes, and one athlete takes about 3 minutes to clear a lane. Don't schedule back-to-back with barely any margin — build in a real buffer, more like 3–4 minutes, so nobody feels rushed off the lane and staff have time to reset between groups. That lands your natural start interval around 6–7 minutes for a new group of 4. Tighter than that and lanes back up the moment anyone runs even slightly long. Looser and lanes sit idle, running the day longer than it needs to be.
Heat size is decided by how many of each station you have. If you have 2 SkiErgs, 2 rowers and 4 sled lanes, the sled is still the ceiling — but now it can take a group of 4 per interval instead of one person at a time.
A simple model:
- Number of parallel athletes ≈ number of units of your tightest station
- Start interval ≈ the time one athlete blocks that station, plus a real buffer
- Total capacity for the day = (open hours ÷ start interval) × parallel athletes
With the example: a 4-hour race window ÷ 6 min ≈ 40 intervals × 4 parallel athletes = ~160 athletes. That's your approximate ceiling capacity for the day.
Example: 40 athletes, 4 sled lanes at ~3 min/person + buffer (~6 min interval)
Illustrative only — swap in your own lane count, station time, and headcount.
| Start time | Athletes | All 4 lanes free again |
|---|---|---|
| 08:00 | #1–4 | 08:06 |
| 08:06 | #5–8 | 08:12 |
| 08:12 | #9–12 | 08:18 |
| 08:18 | #13–16 | 08:24 |
| … continues every 6 min … | ||
| 08:54 | #37–40 | 09:00 |
All 40 athletes started, none of them ever queued at the sled, and nobody felt rushed off the lane — the whole field is through in exactly an hour, with a comfortable buffer built in throughout.
See how RoxRace plans this for you
Heat sizing and start intervals, worked out automatically.
Practical tips for the day
- Don't mix levels at random. Group faster athletes into early heats, beginners later, so nobody catches up to the person ahead.
- Run heaviest first, lightest last. Put the Pro divisions first, so the sled carries its maximum weight from the start. As lighter divisions come later, your staff remove weight — quick and easy. Adding weight mid-race, on the other hand, costs time and creates stoppages. The same principle applies to any equipment that changes between levels: start heavy, work down.
- Have a clear start clock. Athletes should know exactly when they go.
- Staff the bottleneck station. One person at the sled keeping an eye on the flow is worth gold.
- Show results live. Nothing lifts the energy like seeing your time and placing right at the finish.
- Make stations foolproof with clear signage. Post clearly and large at each station how many laps, lengths or reps apply — and per division if they differ. An athlete who has to stop and ask "how many laps?" slows themselves and everyone behind them. Clear signs save more time than you'd think.
- Staff the counting stations, especially wall balls. At high rep counts (e.g. 100 wall balls) people lose count and either cut it short or stop, unsure. A judge counting out loud keeps the flow going and keeps results fair. Prioritize staffing where reps are high and easy to lose track of.
How RoxRace does it for you
Everything above — heat planning, start intervals, the optimal number of athletes per slot — RoxRace works out for you automatically. You enter how many stations and athletes you have, and the system builds a schedule that flows.
And it doesn't stop at the planning:
- Before: registration and payment online, start lists ready.
- During: live timing with splits per station, and results on screen at the finish — athletes see their time and placing the moment they cross the line.
- After: a finished, public results list in seconds. No manual tallying, no sending things out, no Excel puzzle on Sunday night.
You run the event — RoxRace handles everything around it.
Want to see how it looks?
Create a free account, and a complete demo race is waiting inside — with heats, athletes and timing — ready for you to click around in. And if you'd like, we'll set up your next event for you, free, so you can try it for real.
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