Four Katsuo Stamina tablets weigh 1.6 g and carry about 6 kcal. That tells you straight away what it isn’t: it is not a fuel. A single gel has roughly fifteen times the energy. So if Katsuo Stamina has a place in a race plan, it is for what’s in it, not for calories.
What is Katsuo Stamina made from?
Katsuo Stamina is made in Japan from bonito, the fish the Japanese call katsuo. The core ingredient is a migratory fish extract. The compounds it is built around are small peptides made of two amino acid units, beta-alanine and methylhistidine.
Bonito and tuna are migratory fish that swim long distances without stopping, and their muscle tissue is naturally rich in these peptides. That is where the extract comes from, and it is the reason the product is made from fish rather than synthesised.
What does the nutrition label show?
Per serving of 4 tablets (1.6 g):
| Nutrient | Per 4 tablets |
|---|---|
| Energy | 6.29 kcal |
| Protein | 0.49 g |
| Carbohydrate | 1.06 g |
The other ingredients are there to make the tablet: dextrin, reduced maltose syrup, starch, microcrystalline cellulose, magnesium stearate and shellac.
The sodium content is negligible. Don’t count Katsuo Stamina towards your sodium plan on a hot day. That needs its own line in your race nutrition.
How is it taken?
With water, before and during an event, on a schedule set by sport and distance. A half marathon is 4 tablets 30 minutes before the start. A trail race over 30 km is 8 tablets before, then 4 every 90 minutes. The full list for running, trail, cycling, climbing, swimming and rowing is on the Katsuo Stamina page.
If you are racing long, the dose count adds up fast. We worked out how many tablets to pack for common ultra finish times in Katsuo Stamina for Ultramarathons.
Who shouldn’t take it?
Anyone with a fish allergy. The tablets contain bonito, and there is no fish-free version.
Everyone else should still try it in training first. Take the full race-day schedule on a long run, with your usual gels and drinks, so nothing about race morning is new.
Where it fits
Katsuo Stamina sits next to your carbohydrate, fluid and electrolyte plan, never in place of any of them. Get those three right first. They decide most of what happens in the last hour of a long race.
