The two main factors you are going to be balancing when deciding how best to fuel a ride are intensity and duration.
If the intensity is low, and the duration is low, then, broadly, you shouldn’t require anything too specific in terms of pre/post fueling or on the bike fueling. For example, under 60-90 minutes, at an intensity when, for most of the ride, you can easily talk in whole sentences, then you won’t need much – the ride can be fueled on your internal stores.
If the intensity is going to be high (whereby it is difficult to talk in whole sentences – which it commonly is for steep, technical MTB riding) but the duration is low, then you may require a small amount of pre-fueling (something more carbohydrate-based, such as a banana or bar) to help maintain energy levels, especially out toward the end of a 60-90 higher intensity session in technical terrain. Running low on energy can affect focus and concentration especially, and this is where you might be at higher risk of making a mistake and crashing.
If the duration is over 90-minutes, then you may need to consider fueling on the bike, especially if you are likely to go a long way over that 90-minute mark (e.g. 3 hours). The advice here is to fuel early and fuel often, not waiting until late in the ride with flagging energy levels and trying to play catch up (a very common error in MTB). After such rides, consider having a main meal that includes both starchy carbohydrate foods, but also quality protein foods to aid recovery.
The other very important factor to consider is hydration. For shorter duration rides, water is generally okay. But for longer duration, higher intensity riding, especially in the heat, consider an electrolyte drink.
The final tip is to avoid doing skills practice in a low energy state. The technical nature of learning MTB skills requires a lot of brain fuel, yet it is very easy for people to underestimate how much they need to focus and energy.
Jamie has a Post-Graduate Diploma in both Nutrition Medicine and Sport & Exercise Medicine. He is also a New Zealand Registered Nutritionist (NZNS). He creates custom plans for mountain bikers and trail runners. Find out more about his services here.