A Complete Guide to Energy Gel Types: How to Choose Between Solid, Semi-Solid, and Liquid

Introduction

The second half of a marathon is often called “where the real race begins,” and one of the biggest variables at that point is energy replenishment. Glycogen depletion (commonly known as “hitting the wall”) causing your pace to collapse is the nightmare of most runners. The energy supplement market is vast and diverse—liquid energy gels, semi-solid gels, chewable energy gels, solid energy bars—each performing differently in terms of digestion speed, portability, and stomach irritation.

Major marathon events in Taiwan (ING Taipei, Wan Jin Shi) are also increasingly offering energy gels at aid stations, but smart runners should know how to tailor their own fueling strategy rather than simply relying on race-provided supplies.

Core Differences Among the Three Main Types

Liquid Energy Gels (Gel / Liquid Gel)

The most mainstream race fuel, each packet is about 20–25ml, containing 20–30g of carbohydrates. No chewing is required, and it can be swallowed quickly.

Absorption speed: Faster (takes effect in 30–45 minutes)
Stomach irritation: Some people are sensitive to concentrated formulas and need to take it with plain water
Portability: Excellent—can be tucked into a race belt or vest pocket

Mainstream options:

• GU Energy Gel (USA, multiple flavors)
• MAURTEN Gel 100/160 (scientifically formulated, hydrogel form, lowest stomach irritation)
• SIS GO Isotonic Gel (isotonic, no need to take with water)
• PowerBar PowerGel

Semi-Solid Energy Chews (Chews / Gummies)

Somewhere between solid and liquid, with a gummy-like texture that requires light chewing before swallowing. Each packet contains 2–4 pieces and can be consumed in batches.

Absorption speed: Moderate (slightly slower than liquid gels, as chewing and breakdown are required)
Stomach irritation: Relatively mild
Portability: Slightly bulkier than liquid gels, but still convenient

Mainstream options:

• Clif Bloks Energy Chews
• GU Energy Chews
• Honey Stinger Organic Energy Chews

Solid Energy Bars (Energy Bar / Real Food)

Contain more complete complex carbohydrates plus small amounts of protein and fat, suitable for fueling during non-intense phases of ultramarathons or long trail runs.

Absorption speed: Slow (takes 1–1.5 hours to be fully utilized)
Stomach irritation: Lowest, closest to normal food
Portability: Bulkier and heavier; difficult to eat at higher paces

Local Taiwanese options: Taiwanese ultramarathon runners often make their own fuel, such as bananas, red bean rice balls, and sweet potatoes—effectively localized versions of “real solid” fueling that perform just as well as commercial energy bars during long, low-intensity runs.

Comparison Table of Mainstream Energy Gels

Fueling Strategy Recommendations for Taiwan Marathons

Full Marathon (42.195km) Fueling Plan

Modern sports science recommends marathon runners consume 60–90g of carbohydrates per hour. Targeting a 4-hour finish:

• Every 45 minutes, take one packet of liquid energy gel (about 25g of carbs)
• A total of 4–5 gels is needed for the entire race
• Pair with water or electrolyte drinks from aid stations

Special Considerations for Taiwan’s Summer Races

Taiwan’s summer heat accelerates electrolyte loss (sodium, potassium, magnesium). Pure carbohydrate gels are not enough—electrolytes need to be replenished:

• Choose gels that contain electrolytes (such as GU Roctane)
• Pair with electrolyte tablets (Nuun, Precision Hydration) dissolved in water
• Avoid drinking only plain water during the race, as this increases the risk of hyponatremia

The Importance of Digestion Testing

Never try a new energy supplement for the first time on race day. Everyone’s gastrointestinal tolerance to energy gels differs—some people are allergic to maltodextrin or fructose, and some cannot digest solid food during high-intensity running. You should fully simulate your race fueling strategy during training, including flavors and brands.

Strategies for Using Caffeinated Energy Gels

Caffeinated energy gels (typically containing 50–100mg of caffeine per packet) can enhance focus and alleviate fatigue in the latter half of the race, making them a secret weapon for many elite runners in the second half:

• Strategic use: Only take caffeinated gels in the latter half (around the 30–35km mark) for a more pronounced effect
• Daily caffeine consumers: If you drink coffee every day, reduce caffeine intake 7 days before the race to boost its effectiveness on race day
• Caution for the sensitive: Some people are sensitive to caffeine; taking caffeinated gels at high intensity may cause heart palpitations or gastrointestinal discomfort

Practical Tips

• Carry one more gel than planned for a full marathon; when the weather is hot or your pace is slower than expected, fueling frequency needs adjustment.
• Solid bananas are the most common solid food at Taiwan marathon aid stations. Runners at a pace faster than 6 min/km can usually eat while running, making them more convenient than energy bars.
• Although MAURTEN is expensive (over NT$180 per packet), it is worth the investment for runners with sensitive stomachs or those whose digestive systems tend to shut down at high intensity.
• Energy gels should be taken with about 200ml of plain water (except SIS Isotonic), so make sure to consume them near an aid station—don’t eat one between stations when there’s no water available.

Conclusion

Energy fueling strategy is the most overlooked aspect of marathon training. Understanding the characteristics of different supplements, repeatedly testing them in training, and finding the products and timing your digestive system can tolerate are the keys to confidently maintaining your target pace to the finish line on race day.

Related Reading

• Solid Food vs. Energy Gels During Races: How to Choose the Fueling Form That Suits You Best
• Energy Replenishment During Exercise: Comparing Gels, Bars, and Real Food
• Sports Supplement Buying Guide: Differences Between Energy Gels, Bars, and Electrolytes
• Road Running Fuel: When to Use Gels, Bars, and Chews