How do I know how many carbs I need for a session?

Doing Reinstein in an hour, currently eating my overnight oats (70g) soaked in milk with a tablespoon of peanut butter, maple syrup and half a banana.

How do I find out how much oats I really need for a given training session? I want to fuel well for the session but not over eat.

It is a bit late, should be eating 3 hours before and if you can’t do that it should have been the previous evening. 45 minute to 1 hr 30 is the worst time to eat before a session. For me I can just about get away with 1 hour 45 before but don’t normally bother

Better just to have some simple sugars 20 minutes before or during the warmup. If I know I’ve under fuelled the night before (very rare) I eat half a banana 15 - 20 before the workout and the other half during the warmup or in one of the rest intervals.

kJ depends for the session depends on your FTP, it shows you in the workout preview.


Hope it went well!

Like @Bbt67 says, your FTP determines how many calories you will burn. If you go to the Reinstein workout page it’ll tell you your figure. For me at 270 FTP it’s 1,062 - but it could be a lot higher or lower for you.

My approach - based on Amber Malika’s advice on the TR AACC podcast - is to match the calories consumed before, during, and just after the ride with the calories burned.
Then the intensity of the ride will determine whether I make it high carb, medium carb, or low carb (as well as determining the timings of the food intake).

So if I was doing Reinstein (which has some fairly intense over/under intervals) on a weekend morning, I would match the 1,062 calories burned with something like:

80g oats (dry weight), 35g sultanas, 25g scoop peanut butter, 10g honey (2+ hours before)
1 banana (1 hour before)
2x bottles made with 50g energy drink mix each (during)

If I was doing a lower intensity session like Baxter I’d be more likely to cut the sugars and match the calories with a higher proportion of protein and fats, e.g. just have sugar-free squash instead of the energy drink mix, use more peanut butter, substitute some of the oats for scoops of greek yoghurt, have a protein bar, etc. I might even do an easy session fasted and then replace all the calories after the ride.

This is the spreadsheet I created to figure it out. It’s locked for editing but if you do “File > Make A Copy”, you can make your own version and personalise it. Feel free to PM me if you want instructions.


Wow, that’s a great response, thank you!
Plenty for work off from there.

606kJ(cal) just means that I’ll be burning 606kcal, right?
Because if I type “606kj in kcal” into Google, it gives me a way lower kcal number… Probably a stupid question, please forgive me.

No, not a stupid question. Kj is an accurate measure of how much energy we put into the pedals, measured by the power meter and is not necessarily the same as calories burned. However, by mathematical coincidence, for cycling it just happens to be a pretty good approximation. Great explanation on the TR blog here.

Anyway, in your case to match 606 calories, you might adjust your meal to:
60g oats (dry weight)
20g peanut butter
10g honey / syrup
1/2 medium banana
…and then have one bottle of energy drink with 50g powdered mix and one bottle of water during the session.

Follow up the session with a quick recovery drink / snack (a little bit more carbs to top up glycogen and maybe some protein too, could be a recovery shake, or maybe the other half of the banana with some greek yoghurt?), and you should be good to go the rest of your day having normal meal portions and not feeling like you want to eat your entire family.


In response to the original question - no idea! However I love your overnight oats recipe and I’m going to try it next Sunday😊


Andy, don’t forget to add a pinch of salt and… An espresso! It’s awesome :grin:

this might help!

and as someone mentioned, get those solids in hours before. if you’re riding very early, stick to a sports drink or a gel to get through the session. if it a high intensity session, lean the diet towards carbs the night before and you’ll be smashing.

good luck!

This is my favorite guide to nutrition.

You can look at their ride references and compare them to your TR or outdoor rides to get an idea of what might work for you.

Eating to Suffer:

I also find these fact sheets very useful: