PERPETUEM: THE COMPLETE GUIDE TO LONG-DISTANCE FUELLING

For endurance events lasting three hours or more, energy gels alone are rarely enough. This guide explains what Perpetuem is, when to use it, how to mix it, and how to build it into a complete long-distance nutrition strategy.

What Is Perpetuem and Why Is It Different?

Perpetuem is Hammer Nutrition's dedicated long-distance fuel, designed specifically for efforts lasting three hours and beyond.

Unlike energy gels, which provide a concentrated hit of carbohydrate calories, Perpetuem combines carbohydrates, protein and healthy fats in a single formula. This combination is designed to support sustained energy output over many hours without the digestive issues that can arise from relying solely on carbohydrate-based fuels during prolonged exercise.

The inclusion of protein helps reduce muscle breakdown during long efforts, while the fat component supports fat metabolism — an important energy pathway during extended low-to-moderate intensity exercise.

Perpetuem is available in two forms:

• Powder — mixed with water to create a liquid fuel that can be carried in a bottle or hydration pack
• Perpetuem Solids — chewable tablets that provide the same formula in a convenient solid format, ideal when carrying liquid is impractical

When to Use Perpetuem (vs Gels)

The general rule is straightforward: use energy gels for efforts under three hours, and introduce Perpetuem for anything longer.

Use Hammer Gel when:

• Your event or training session is under 2–3 hours
• You need fast, portable calories during racing
• You are supplementing a longer session alongside Perpetuem

Switch to Perpetuem when:

• Your effort will last 3 hours or more
• You need a sustained calorie source that includes protein
• You want to reduce reliance on repeated gel intake over many hours
• You are doing back-to-back training days and want to protect muscle

For very long events such as Ironman triathlons, ultra-marathons or multi-day adventures, Perpetuem can serve as your primary calorie source throughout, supplemented with gels during higher-intensity sections such as race starts or climbs.

Read more: Hammer Gel Fueling Guide →

How Many Calories Do You Need on Long Efforts?

Hammer Nutrition's approach is to supply the calories your body can effectively absorb and utilise — not the maximum possible amount.

For most endurance athletes, this means targeting 100–180 calories per hour during sustained effort. Perpetuem powder provides approximately 270 calories per serving (two scoops), making it easy to portion your intake across the hours of your event.

Factors that influence your calorie needs include:

• Body weight and composition
• Exercise intensity and terrain
• Ambient temperature
• Individual metabolic rate
• Duration of the effort

Start conservatively and adjust based on how you feel during training. The goal is steady, comfortable energy — not a full stomach.

Mixing Guide — Liquid vs Solid

Perpetuem Powder

The standard mixing ratio is two scoops (approximately 270 calories) per 500–750ml of water. You can adjust the concentration based on your preference and the conditions:

• Cooler conditions: mix more concentrated to reduce the volume of liquid you need to carry
• Hotter conditions: use a more dilute mix and increase your plain water intake alongside it

Perpetuem can be mixed in advance and carried in a standard water bottle or hydration pack. For very long events, pre-mixing multiple bottles and leaving them at aid stations or with support crew is a common strategy.

Important: Perpetuem should not be left in warm conditions for extended periods once mixed. In hot weather, mix fresh or keep pre-mixed bottles chilled until needed.

Perpetuem Solids

Perpetuem Solids provide the same formula in a chewable tablet format. Each tube contains six servings and is easy to carry in a jersey pocket, race vest or bento box.

Solids are particularly useful:

• When carrying liquid is impractical (trail running, mountain biking)
• As a backup to liquid Perpetuem during very long events
• When you want variety in texture and format during multi-hour efforts

Shop Perpetuem Powder →
Shop Perpetuem Solids →

Perpetuem for Cycling vs Running vs Triathlon

Cycling

Perpetuem is particularly well suited to long rides, where carrying a bottle is straightforward and the lower-impact nature of cycling makes digestion easier. Many cyclists use a concentrated Perpetuem bottle as their primary calorie source, supplemented with water from aid stations.

Running

For running, Perpetuem Solids are often the more practical choice, particularly during trail and ultra events where carrying multiple bottles is difficult. Liquid Perpetuem works well when using a hydration vest with a dedicated nutrition pocket.

Triathlon

Perpetuem is a popular choice for Ironman and long-course triathlon, where athletes need sustained calories across a 5–17 hour effort. A common strategy is to use Perpetuem as the primary fuel on the bike leg, then transition to gels and Perpetuem Solids on the run where liquid carrying is more restricted.

Combining Perpetuem with Gels, Electrolytes and HEED

Perpetuem works best as part of a complete fuelling system rather than in isolation.

Perpetuem + Hammer Gel

During high-intensity sections of a long event — race starts, climbs, sprint finishes — adding a Hammer Gel provides a fast-acting carbohydrate boost alongside your sustained Perpetuem calories. This combination gives you both immediate and long-term energy support.

Perpetuem + Endurolytes

Perpetuem does not contain a full electrolyte profile, so pairing it with Endurolytes capsules or Endurolytes Extreme is important for events lasting several hours, particularly in warm conditions. Take electrolytes on a regular schedule rather than waiting until you feel symptoms of depletion.

Perpetuem + HEED

If you prefer to carry your electrolytes in liquid form, HEED Sports Drink can be used alongside Perpetuem. Use HEED in one bottle and Perpetuem in another, alternating between them based on your calorie and hydration needs.

Explore Endurolytes →
Explore HEED →

Caffeine Variants — When and Why

Perpetuem is available in a caffeinated version for athletes who want additional mental alertness during long efforts.

Caffeine can be beneficial during:

• The later stages of very long events when fatigue sets in
• Night sections of ultra-endurance events
• Early morning race starts

Use caffeinated Perpetuem strategically rather than throughout an entire event. Sustained caffeine intake over many hours can increase anxiety, disrupt sleep during multi-day events, and lead to dependency effects. Alternating between caffeinated and non-caffeinated versions is a common approach for ultra-distance athletes.

Common Mistakes on Long Events

Starting Perpetuem too late. Begin fuelling with Perpetuem from the first hour of a long effort, not when you start to feel hungry or tired. By the time energy depletion is noticeable, performance has already dropped.

Mixing too concentrated in heat. A very thick Perpetuem mix can be harder to digest in warm conditions. Dilute your mix and increase plain water intake when temperatures rise.

Skipping electrolytes. Perpetuem provides calories and protein but is not a complete electrolyte replacement. Always pair it with Endurolytes, particularly during warm weather or sweaty efforts.

Not practising in training. Your race-day nutrition strategy should be tested thoroughly in training before you rely on it in competition. Long training rides and runs are the ideal opportunity to dial in your Perpetuem concentration, timing and combination with other products.

Leaving mixed Perpetuem in the heat. Once mixed, Perpetuem should be consumed within a few hours, particularly in warm conditions. Pre-mix fresh bottles where possible.

Race Day vs Training Use

Training is where you develop and refine your Perpetuem strategy. Use your long sessions to test:

• Your preferred mixing concentration
• How many calories per hour works for your body
• Which combination of Perpetuem, gels and electrolytes suits your event format
• Whether liquid Perpetuem, Solids or a combination works best for your discipline

On race day, stick to the strategy you have tested. Avoid trying new concentrations, new combinations or new products for the first time during a race.

Explore Our Full Range of Guides

• Beginner's Guide to Endurance Fuelling → — start here if you're new to endurance nutrition
• Hammer Gel Fueling Guide → — dosing, timing and race-day gel strategy
• Electrolytes for Endurance Athletes → — complete electrolyte guide
• Race Nutrition Planner → — event-specific fuelling frameworks
• Recovery Nutrition Guide → — what to do after long efforts
• Fuelling Guidelines → — Hammer Nutrition's complete fuelling framework