A 100km trail ultra that takes you 16 hours means eleven doses of Katsuo Stamina on the label schedule: one before the start and ten on the course. That is 48 tablets, and 40 of them have to be in your vest or drop bags before the gun goes. Work it out at the start line and you will run short somewhere in the second half.
This page turns the label directions into numbers you can pack.
What is Katsuo Stamina?
Katsuo Stamina is a Japan-made tablet derived from bonito fish, taken with water before and during endurance events. The label gives a separate schedule for each sport and distance. It sits alongside your carbohydrate, fluid and electrolyte plan. It does not replace any of them.
The label schedule for ultras and long trail races
- Road ultra: 8 tablets 30 minutes before the start, then 4 every 120 minutes.
- Trail 15 to 30 km: 8 tablets 30 minutes before the start.
- Trail over 30 km: 8 tablets 30 minutes before the start, then 4 every 90 minutes.
The trail schedule is tighter than the road one. Trail races keep you out longer for the distance, and the label reflects that.
How many tablets to carry for your race
Count your doses from your expected finish time, not the distance. Take the pre-start dose at home or in the start pen, then divide your time on course by the dose interval and round down. Skip any dose that would fall at the finish line.
| Race and expected time | Schedule | Doses on course | Tablets to carry |
|---|---|---|---|
| Trail 50 km, 10 hours | Every 90 min | 6 | 24 |
| Trail 100 km, 16 hours | Every 90 min | 10 | 40 |
| Road 100 km, 12 hours | Every 120 min | 5 | 20 |
| Road 50 km, 6 hours | Every 120 min | 2 | 8 |
Add the 8 pre-start tablets to each total. If you expect to be slower than planned, and in Malaysian heat most people are, pack one extra dose.
Where to put them
Split the tablets between your vest and your drop bags so no single failure leaves you with none. A small zip bag of 8 in the vest covers two doses. Put the rest in drop bags at the points you will reach around the 90 or 120 minute marks. Set a repeating timer on your watch, because at 3am on a climb nobody remembers what time they last took anything.
What Katsuo Stamina doesn’t cover
It isn’t a fuel and it isn’t an electrolyte. On a long, hot race you still need carbohydrate every hour, fluid to thirst and, for many runners, planned sodium. If you are not sure whether you need that last one, work it out with How Much Sodium Do You Lose Running in Malaysian Heat?
Katsuo Stamina contains bonito fish, so it is unsuitable for anyone with a fish allergy. Try the full schedule on a long training run first, never for the first time on race day.
The full schedule for every sport is on the Katsuo Stamina page.
