Winter trainings & skiing marathon: how to keep the energy until the end ⛷️

Winter training and ski marathons place serious demands on the body.
In cold conditions, your body burns significantly more energy — not only for movement, but also to maintain core temperature. That’s why a successful finish requires more than just good fitness or the right skis.

In this article, we share practical advice on how to fuel with carbohydrates before the start, when to take energy on the course, and why consistent fueling helps you maintain pace in the final kilometers and recover faster after the effort.

⚡ Training for a ski marathon?
All SiS energy gels are currently –20% — the perfect time to stock up on high-quality fuel for race day.
👉 Find the right fuel for the course

1. Why does the body burn more energy in winter?

When exercising in cold environments, the body must produce heat in addition to powering movement. This increases overall energy expenditure compared to warmer conditions — your body is essentially working double duty to maintain core temperature and muscle function.

As a result, winter marathons and long training sessions place a noticeably higher load on the body, and energy stores are depleted more quickly.

In ideal conditions — when we’ve eaten and hydrated well beforehand — carbohydrate stores typically last around 90 minutes. However, most ski marathons last well over 90 minutes.
On top of that, additional energy is lost simply to maintaining body temperature.

That’s why proper carbohydrate loading before exercise and regular energy intake during the effort are essential. They help prevent sudden drops in energy and avoid completely “running out of fuel.”

2. Carbohydrate loading before the start

In the days leading up to the marathon, we recommend increasing the proportion of complex carbohydrates in your diet, such as:

– rice
– pasta
– potatoes
– oats for breakfast

This helps fill muscle glycogen stores and provides more energy for race day. Higher carbohydrate availability also improves the body’s ability to absorb carbs while exercising.

3. Race morning – don’t forget hydration

Before heading to the course — while traveling to the start area — we recommend sipping a sports drink, for example:

– SiS GO Electrolyte
– Leader Performance Sports Drink

Each sip provides:
• fluid
• electrolytes
• a small amount of energy

This creates a solid foundation for the effort ahead.

4. Fueling on the course – start early

Don’t wait until you feel tired.
We recommend starting energy intake 20–25 minutes into the race and continuing at the same interval throughout.

If possible, use slightly more solid products early on, such as:

– SiS Beta Fuel Energy Chew

or grab something more solid at aid stations.

Consistent fueling allows the body to work efficiently in the later stages of the course. If you start too late or leave long gaps, your body will already have used most of its reserves — making the final kilometers significantly harder.

Your body shouldn’t suddenly realize that it urgently needs energy.

5. If you don’t have your own drink with you

Between drink stations, use only isotonic energy gels, such as SiS GO Energy Gel.

This was the world’s first isotonic energy gel, and all gels in the SiS GO range do NOT require additional water for absorption — making them an ideal solution when drinking isn’t possible.

🧃 Right energy at the right time matters.
Find the gels and bars that suit you before the start — all SiS gels are currently –20%.
👉 Isotonic gels and bars

6. IMPORTANT: What you need to know about sugar-based gels

All energy gels that contain fructose and/or glucose require water for proper absorption.
Without sufficient fluid intake, gastrointestinal issues are very likely to occur. The higher the sugar content of the gel, the more water is needed for absorption.

This also applies to SiS Beta Fuel Energy Gel, all other high-carbohydrate gels, and hydrogel products — use these primarily at aid stations where water is available.

7. Energy also affects recovery

More energy during the race doesn’t just mean a faster finish — it also has a major impact on how you feel afterward and in the following days. When the body isn’t completely depleted:

– recovery is faster
– you feel better overall
– the following workdays and training sessions are more productive

🏁 Finish strong. Recover faster.

Winter marathons and long outdoor sessions require thoughtful preparation. Keep your carbohydrate stores topped up, start fueling early on the course, and choose products based on whether you have access to water.

Consistent energy intake influences both your performance on the course and how you feel afterward.

🎉 All SiS energy gels are currently –20%.
👉 Shop before the start

Wishing you enjoyable winter adventures, great glide on race day and a strong finish! ❄️⛷️