Fuelling threshold workouts

Hey y’all, great product, great forum, great community.

I’ve heard on the podcast that carbohydrate intake is advised for workouts of high intensity of 60mins plus.

At what point does ‘high intensity’ begin?

I’ve just dragged myself through ‘Donner’ in week 2 of mid vol SSB2. Ftp 280watts, 4.3w/kilo. So these were 3 x 270-270w x 12 minute intervals.I had a decent sized bowl of porridge around 3 hours prior to the workout, was feeling fairly fresh, but I was really yearning for a gel, some energy drink, sweets, anything sugary to get me through the last interval. I resisted, but felt horrible. I generally try and avoid taking on carbohydrates unless the workout is vo2, anaerobic. But am I ‘allowed’ something delicious to get me through threshold workouts? I refuelled properly afterwards.

Any feedback would be great!!


Don’t over-engineer this. If you think your body needs some fuel then give it fuel. I’ll do 1-2 SIS gels in a 90 min threshold workout with a bottle of my infinit blend. Keeps me feeling strong(ish) to the end. It’s a very personal balancing act.


I expect you didn’t have enough fuel to begin (perhaps not enough carbs the day before) with so the porridge just got you through the first part.

I’ve been closely following one of habits that Fitzgerald writes in his book, The Endurance Diet, which is “eat enough.” My workouts have improved since following that advice.


Donner is only 1 hr long…but really only 36 minutes of “intensity”…or roughly 600 Calories.
Your porridge would have provided perhaps 300 Cal plus your muscles would have provided at least another 1,000+ Cal so you should have had more than enough carbs onboard to fuel the workout. I’m guessing it was something else besides low glycogen stores which caused your “bonk”.

Properly fed, I almost never have to feed during a trainer workout.

Here’s a free Time-in-Zone/TSS calculator that shows Calories burned for the workout (which TR also does); you can use that info to fuel properly pre-workout. :+1:

I think there is something else going on here. I would have thought a meal 3 hours before would be more than sufficient to fuel a 60 min threshold workout. Further, I also would think that for a trained cyclist (which 4.3 w/kg would indicate) likely a 60 min effort at threshold wouldn’t be a problem in a fasted state.

I took a look at your ride history and this week instead of having a rest day Wednesday, you did Pettit in the morning 12 hours after riding Huffaker. That extra bit of riding could perhaps have put more fatigue in your legs than you realize.

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