Nutrition for indoor training

Gemma Sampson- Advanced Sports Dietitian

Dietitian Without Borders

With COVID-19 causing global lockdown and social isolation, there’s been a huge rise in people (including myself) switching from outdoor to indoor training. This typically means changes in the distance, duration and training intensity that you can maintain indoors compared to on the road. Naturally what you can and do eat for indoor training should change a bit.

Should you fast or fuel indoor training sessions?

Whether you should train fasted or fueled depends on the type of ride you are doing. Never eating when training is probably one of the biggest mistakes I see cyclists at all levels making. In my practice as a sports dietitian I often see cyclists undereating during training but then overeating while they rest. You want to fuel for the work required and adapt what you eat to the specific training that you are doing.

The higher the intensity of your cycling the more carbohydrate your body uses, while slower easier rides use more fat instead. Indoor training sessions tend to be shorter but more intense, which means they use more carbohydrate and energy than a longer slower duration ride which means it is better to fuel up.

Fasted training once or twice a week can be a good way to improve your body’s ability to use fat as fuel which is especially useful for endurance cycling. The key thing is to go much easier than you would on your normal rides. Ride too fast, too hard and you’ll end up using carbohydrates as a fuel source, be super hungry afterwards and more likely to overeat the rest of the day. As a guide I’d suggest going 40-50 watts lower than you typically would on an hours ride and make sure you have a healthy snack ready and waiting to eat afterwards.

Real food for indoor training nutrition

On the road I see too many athletes relying on commercial sports nutrition products – gels, drinks and bars when they could actually fuel better with real food. With shortages in some supermarkets. I am a huge advocate for using real food as fuel when training both indoors and outside. With more time on your hands it’s the perfect opportunity to experiment.

Wraps, sandwiches, mini pancakes, mini boiled potatoes rolled in salt, bananas, homemade flapjack, dried dates and apricots are all great options of foods you can make at home and fuel on your indoor rides. If you have never made rice cakes before this is the perfect opportunity to experiment with flavours and taste what the Pro’s are eating on the World Tour. My favourite rice cake flavours are lemon coconut and apple cinnamon.

Staying hydrated while indoor training

Training indoors you are more inclined to sweat more Electrolytes. Aim to be drinking at least 1 to two bottles of fluid per hour you spend training indoors. The easiest way to determine your sweat rate and how much you need to drink, is to weigh yourself before and after a training session then add the fluid you drank. For example if you are 1kg lighter after an hour of training and you drank 1x 500ml bottle, you should aim to drink between 2-3 bottles of water and electrolytes in similar sessions. By using electrolyte tablets you will better absorb the fluid you drink as well as replace the losses in your sweat.

Nutrition for weight loss/maintenance when training indoors

If you’re used to racking up big mileage every week, you probably have a healthy appetite and are used to eating a large volume of food. If your training drops but you still eat the same amount, it’s possible that you may gain some additional weight. By slightly reducing your portion sizes of starchy carbohydrates at meals (rice, bread, pasta, potatoes etc) and greatly increasing the amount of vegetables (fresh, frozen or canned) in every meal you can keep the same volume of food and reduce your overall calorie intake without compromising your weight.


Gemma Sampson is an Advanced Sports Dietitian specialising in sports nutrition for amateur and elite cyclists and triathletes. Based in Girona, she provides sports nutrition coaching in person and online to provide practical, realistic and sustainable strategies to fuel smart during training and competition for better body composition, health and competitive results. Her PhD research at Liverpool John Moores University focuses on the nutrition knowledge, behaviours and practices of endurance athletes during competition.