Ultramarathon Drop Bags: What to Pack, With a Checklist by Distance

What is a drop bag, and what goes in yours? A drop bag checklist for 50K, 50-mile and 100-mile ultras, plus how to label and organise it for quick stops.

Why Your Drop Bag Can Decide Your Race

Drop bag strategy separates runners who finish ultras from those who spend twenty minutes at an aid station trying to remember where they packed their headlamp batteries. Most DNFs trace back to fixable problems: blisters that were ignored for too long, a nutrition meltdown from relying on unfamiliar aid station food, or a temperature drop that caught someone without an extra layer. A well-planned drop bag addresses all three. If you're new to the format, drop bags are containers you leave at designated aid stations before the race starts. Race staff transport them to those points, and you access them when you arrive during the race.

The goal is not to pack everything you might possibly need. It's to pack what you will likely need, organized so you can find it fast and leave without losing five minutes.

How Drop Bags Work in Practice

Race directors designate which aid stations accept drop bags. For a 50K, that might be one location. For a 100-miler, you could have bags spread across four or five stations. Point-to-point courses give you one shot per bag; looped courses may let you access the same bag at the start/finish area on every lap.

Before the race, each bag gets labeled with your name, bib number, and the aid station name. Use a waterproof dry bag and pick something brightly colored so you can spot it in a pile. Some runners wrap their bag in bright tape or tie a bandana to the handle. Whatever works. The faster you find it, the faster you leave.

Write your aid station plan inside each bag. Not a novel, just a short checklist: what to eat, what to swap, what to pick up. When you're thirty miles in and running on four hours of sleep, your executive function is not at its best. The list does the thinking for you.

Packing by Race Distance

50K

A single drop bag is usually enough. Focus on nutrition continuity and one potential foot care stop. Pack:

  • Enough gels, chews, or real food to cover the next segment plus 20% extra
  • A fresh pair of socks
  • Anti-chafe product (Body Glide, Trail Toes, or similar)
  • One backup layer if temperatures drop in the evening or at altitude
  • Caffeine gels or chews for the final third of the race
  • A pre-mixed electrolyte bottle ready to swap

Research consistently shows that GI distress is one of the leading causes of DNFs in ultramarathons (Hoffman et al., 2019; Navalta et al., 2022). One of the strongest defenses against it is using nutrition you've already trained with rather than gambling on aid station options. Pack your proven gels, your familiar drink mix, and a backup option like crackers or boiled potatoes for when your stomach goes sideways.

50 Miles

At fifty miles, gear transitions become more important. You'll likely cross into nighttime hours, encounter more significant temperature swings, and accumulate enough foot mileage to need a real sock change.

For each drop bag:

  • Nutrition for the next segment plus buffer
  • Spare socks (wool or synthetic, not cotton)
  • Blister kit: moleskin, Leukotape, needle, alcohol wipe
  • Headlamp with fresh batteries, or a backup headlamp
  • Warm layer if the back half of the race goes into cold or high elevation
  • Anti-nausea tablets (Tums or similar)
  • Pre-mixed calories in bottles ready to swap
  • Optional: clean t-shirt or base layer for the night section

A shoe change at mile 50-70 is worth considering for longer efforts. Feet swell over the course of a race, and a half-size-up backup shoe can make the difference between a manageable discomfort and something that forces you to slow dramatically (CTS Ultrarunning, 2025).

100 Miles and Beyond

At this distance, your drop bags are essentially a personal aid station system. You're planning around weather windows, day-to-night-to-day transitions, significant foot swelling, crew access restrictions, and the mental low points that tend to cluster between miles 60 and 80.

For each bag at a 100-miler, think in terms of what phase of the race you're entering:

Early bags (miles 20-40): Nutrition top-off, electrolyte reload, sunscreen if conditions warrant. Keep these simple. You should still be feeling good.

Mid-race bags (miles 40-65): Sock change, blister check, headlamp pickup, night layer. This is where most runners hit a low point. A small comfort item, a specific snack you love, or even a short handwritten note from a friend can provide a meaningful mental boost.

Night bags (miles 65-80): Warm layers, extra lighting, easy-to-digest calories like broths, boiled potatoes, or rice balls. Your gut often struggles most here. Hot food is worth having if the aid station doesn't provide it.

Final bags (miles 80+): Stimulants (caffeine), foot care if needed, simple carbohydrates. Don't overthink this bag. You're close.

Research on multi-stage ultra events shows sleep deprivation compounds decision-making difficulties; runners average as little as 4.1 hours of sleep across multi-day events and still compete effectively, but fatigue degrades the ability to problem-solve on the fly (Cadence Nutrition, 2025). A clear written plan in each bag removes the cognitive load from fatigued decision-making.

Foot Care: Your Most Important Category

Blisters are among the most common causes of a painful, slow final third or a full DNF in longer ultras (Relentless Forward Commotion, 2024). Moisture is the main culprit: wet skin loses structural integrity faster, friction increases, and once a hot spot forms it worsens with every stride.

Minimum foot care kit per bag:

  • Fresh moisture-wicking socks (wool or synthetic)
  • Blister lubricant: Body Glide Foot Glide, Trail Toes, or Vaseline
  • Leukotape or moleskin for hot spots already forming
  • Needle and alcohol wipes to drain blisters if needed

If you're racing a course with stream crossings, budget a sock change shortly after those sections. Carrying an extra pair of socks in your vest for immediate use post-crossing, and a fresh pair in your next drop bag, covers both bases.

Nutrition and Hydration Logistics

The most practical approach to drop bag nutrition is portioning by segment. Before the race, map out the time you expect between aid stations. Multiply that by your target caloric intake (typically 60-90g of carbohydrates per hour for efforts over three hours, and up to 90g/hr for races beyond six hours where your gut has been trained for it) and pack that amount plus a 20% buffer (Hoffman et al., 2019).

For liquid calories, pre-mixing bottles at home and sealing them saves time and reduces errors when you're tired. Swap a bottle rather than trying to measure powder with shaking hands.

Include at least one "plan B" food option per bag: something simple and palatable if your primary nutrition stops working. Common backups include crackers, pretzels, boiled potatoes with salt, or rice balls. The variety also helps address appetite fatigue, a real phenomenon in races lasting beyond eight hours.

Weather and Lighting: Plan Around the Course, Not Just the Forecast

Check the specific elevation profile of your race, not just the ambient temperature at the start. Temperatures can drop 6-10°C per 1,000 meters of altitude gain. A runner starting a 100-miler in mild conditions at sea level may spend five hours in genuine cold at altitude in the middle of the night.

Layering system to consider across bags:

  • Wind shell for exposed ridges
  • Insulated midlayer for night sections and high elevation
  • Rain jacket if the forecast suggests any precipitation
  • Beanie and gloves for night/cold sections
  • Buff for versatility

Sunscreen matters more than most runners expect at altitude. A 2024 study published in the Journal of Photochemistry and Photobiology found that ultrarunners can receive up to ten times more UVB radiation than at sea level (Gutiérrez-Manzanedo et al., 2024). Include a small tube in your earlier drop bags.

For lighting, carry your headlamp on your person, but put fresh batteries or a backup headlamp in any bag around the mile marker where you expect darkness. If the transition to night is a grey area depending on pace, keep it in the earlier bag.

Common Mistakes and How to Avoid Them

Overpacking. First-timers pack for every possible scenario and then spend five minutes digging through the bag. Pack for likely scenarios. You will almost certainly need dry socks. You will probably not need a full medical kit.

Packing the same thing in every bag. Think about what the specific section demands. A bag at mile 25 of a daylight 50K has different priorities than a bag at mile 75 of a 100-miler headed into a cold night.

Not labeling the contents. Put a short list inside each bag. Even better, put your written aid station plan inside so you know exactly what to do when you arrive.

Skipping the finish line bag. Bring clean clothes, comfortable sandals, snacks, and anything you'll want immediately post-race. After a 100-miler, dry clothes and a warm layer matter immediately. Your feet may be too swollen for regular shoes.

Relying too much on aid station food. Ultrarunning Magazine notes that GI distress is multi-factorial, but training your gut to handle your specific race-day nutrition dramatically reduces risk (Ultrarunning Magazine, 2024). Aid station food varies by race and is never guaranteed to agree with your stomach.

Key Takeaways

  • Label every bag clearly with your name, bib number, and aid station name
  • Pack nutrition by segment with a 20% buffer and one backup food option
  • Always include dry socks and a blister kit from 50K upward
  • Plan lighting and layers around the specific conditions of each course section, not just the race-day forecast
  • Write your aid station plan inside each bag so fatigue can't derail it

Building Your Strategy Into Your Race Plan

The strongest drop bag strategy starts during training, not the week before race day. The nutrition you practice with is the nutrition that should be in your bags. The gear you test on long runs is the gear that earns its spot. By race week, your bags should already be mostly planned from the log of what worked.

If you want help stress-testing your race readiness before you even pack those bags, Trailia's Race Readiness tool evaluates your preparation across training load, recovery, and race-specific factors. It's a useful checkpoint before committing to a start line.

Pack smart. Run long.

Citations

Frequently Asked Questions

What is a drop bag in an ultramarathon?

A drop bag is a container you leave at a designated aid station before your race starts. Race staff transport it to that point on the course so you can access your gear, food, and clothing when you arrive during the race. It lets you carry supplies through a race without hauling everything on your body from the start.

How many drop bags can you have in an ultramarathon?

This depends on the race. A 50K may allow just one drop bag at a single location. A 100-miler often allows four to six bags spread across different aid stations. Some looped courses let you access the same bag repeatedly as you pass the start/finish area. Always check the race manual for the exact rules and designated locations.

What should I always include in a drop bag?

The non-negotiables for most ultras are: proven race nutrition with a 20% buffer, dry socks, a blister kit, and a written aid station plan. From 50 miles onward, add headlamp batteries, a backup layer, and anti-nausea tablets. Every other item depends on the course, conditions, and distance.

How do I organize my drop bag so I can find things quickly?

Group items into clearly labeled zip-lock bags inside the main bag. Separate categories like nutrition, foot care, clothing, and lighting. Put your written aid station checklist on top so it's the first thing you see. A bright-colored outer bag and a visible label help you locate your bag faster in a pile of other runners' gear.

Should I change shoes during a 100-mile race?

Many experienced ultrarunners recommend having a backup pair of shoes, ideally a half size up, available around miles 50-70. Feet swell significantly over the course of a 100-miler, and a fresh shoe in a slightly larger size can ease pressure and reduce blister formation. A shoe change is not mandatory, but having the option available in a drop bag costs nothing.

What nutrition should I put in my ultramarathon drop bag?

Pack your trained, proven nutrition: gels, chews, drink mix, and any real food you've used in long training runs. Portion it by segment with a 20% calorie buffer and include at least one backup option for when your primary food stops appealing to you. For races over three hours, aim for 60-90g of carbohydrates per hour, and pre-mix your electrolyte bottles so you can swap quickly at the aid station.

How do I prevent blisters using my drop bag?

Include fresh socks and a blister kit at every major drop bag location. Apply lubricant to known hot spots at the start and again mid-race. After any river crossings or wet sections, change into dry socks as soon as possible. If you feel a hot spot forming, stop at your next drop bag to tape it before it becomes a full blister, not after.

What should I put in a drop bag for a nighttime section?

Prioritize warm layers (insulated midlayer, wind shell, beanie, gloves), your headlamp with fresh batteries or a backup headlamp, and easy-to-digest calories like broths, rice balls, or boiled potatoes. Your GI system often becomes more sensitive during night hours, so avoid heavy or unfamiliar foods in these bags.

Can I use drop bags without a crew?

Yes, and this is one of the main reasons drop bags exist. Many ultramarathon runners have no crew and rely entirely on drop bags to access key gear and nutrition beyond what they carry. Planning your drop bag contents carefully means you can be effectively self-sufficient across the full race distance.

What are the most common drop bag mistakes?

Overpacking is the most frequent error, especially among first-timers who bring items for every possible scenario and then lose time searching through cluttered bags. Other common mistakes include packing the same items in every bag regardless of race phase, forgetting a finish line bag with clean clothes and sandals, and relying on aid station food instead of your trained nutrition.

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