Ultramarathon Drop Bags & Crew Support: The Complete Guide

Drop bags and crew support are two of the most underutilized tools in ultrarunning. For most 100-milers, you'll use some combination of both. Most first-timers either overpack their bags with gear they'll never touch, or underthink the whole system and arrive at mile 60 without a headlamp or dry socks. Neither outcome is good.

The logic behind a well-packed drop bag is simple: carry only what you need to reach the next bag, then reload. Crew support follows the same principle: know exactly which stations they can access, what you'll need from them, and how to get out fast. Your bags aren't identical to each other, and your crew's job changes from segment to segment.

This guide covers what to pack, how to think about each station, and how to coordinate drop bags and crew so the two systems work together instead of creating confusion on race day.

Drop Bags vs. Crew Access: How They Work Together

A drop bag is a labeled bag or bin you fill before the race and hand over at the start. Race volunteers drive it ahead and stage it at a specific aid station. When you arrive, you dig through it, grab what you need, and keep moving.

Crew access is different. Your crew drives the course independently, parks at designated access points, and meets you with whatever you need. They can hand things directly to you, manage your gear between stations, and provide real-time support that a pre-packed bag can't. Not all aid stations allow crew; some allow bags but not crew; a few allow both.

Rules vary significantly by race. Most 100-milers allow 2–4 drop bag stations. Crew access is often more restricted, typically limited to 4–8 designated stations with specific parking areas. 50-mile races may allow 1–2 drop bag locations and limited crew access. Most 50Ks allow neither. Always check your race handbook before packing, and brief your crew on which stations they're allowed at and where to park.

Bag logistics also vary. Some races provide labeled bins; others require you to bring your own bag (a clearly labeled drawstring bag or small duffel works well). Write your name, bib number, and station name on the outside in large letters, not just on a tag that can fall off. If you have both a bag and crew at the same station, coordinate in advance so you're not digging through a bag for something your crew is already holding.

Nutrition

Nutrition is the most important drop bag category and the one most runners get wrong. The mistake is either packing the same food for every station or assuming the aid station table will have what you want. Neither is reliable at mile 70 in the dark.

Pack enough calories to cover the segment between stations, plus a modest buffer. At a mid-race station, that usually means 4–6 gels or equivalent, a serving or two of drink mix, and at least one piece of real food.

• Maurten Gel 100 CAF · 4–6 per station for night/late-race segments 100mg caffeine per gel. Use strategically after mile 50, not from the start. Stomach-gentle hydrogel formula holds up late in the race when your gut is tired.
• Tailwind Nutrition Endurance Fuel · 2–3 single-serve packets per station Pre-portioned packets are much easier to manage in a drop bag than loose powder. Provides calories, electrolytes, and carbs in one mix. Good if you want to supplement or replace what the aid station is serving.
• SaltStick FastChews · small tube per bag Chewable electrolyte tablets. Carry a tube in your vest throughout the race and restock from your bag. Sodium, potassium, calcium, and magnesium: the four electrolytes that matter for cramp prevention. Easier to take than capsules mid-run.
• Real food · 1–2 servings By mile 40–50, many runners struggle to stomach gels. PB&J sandwich halves, boiled mini potatoes with salt, or a handful of pretzels travel well in a bag and provide the comfort food effect that helps late in a race.

Hydration

Aid stations refill your flasks. You don't need to carry extra water in your drop bag. What you do need is a backup soft flask in case one fails, and your preferred drink mix if you don't trust the aid station's options.

• Hydrapak SoftFlask Speed 500ml · one backup Soft flasks can develop leaks or sticky valves after hours of use. A fresh flask at mile 50 or 60 costs you nothing in weight and fixes a problem before it becomes a DNF. The Hydrapak Speed fills one-handed and compresses completely when empty.
• Drink mix single-serve packets · 2–3 per station If your stomach has been struggling with whatever the race is serving, having your own known formula is worth the few ounces.

Foot Care

Foot care is where a well-packed drop bag wins or loses a 100-miler. Most DNFs are not fitness failures. They're blister failures, toenail failures, or "I didn't stop to deal with this hot spot at mile 40 and now I can't walk" failures. Invest in this category.

• Leukotape P · small roll per bag The gold standard for blister prevention. Zinc oxide adhesive stays on through sweat, rain, and creek crossings, unlike most medical tape. Apply over hot spots before they become blisters. One roll in each drop bag means you always have fresh tape available.
• Darn Tough Running Socks (Men's) / (Women's) · one fresh pair per bag Merino wool manages moisture and reduces friction better than synthetic in long efforts. A dry pair of socks at mile 50 after a wet crossing feels like a reset. The Darn Tough lifetime guarantee means you replace worn pairs for free.
• Blister needle + alcohol wipes · small sealed bag For draining blisters that have already formed. Drain, dry, tape over. Don't tear the roof off. That skin is protecting the raw tissue underneath. Clean needle, alcohol wipe, gentle drain at the edge.
• Body Glide or anti-chafe balm · one stick Reapply at mid-race and beyond, especially at any point where your gear has gotten wet. Wet skin and repeated motion create friction that wasn't there at the start.

Lighting

Any race with night miles requires a headlamp. Don't wait until the last drop bag before darkness. Put your headlamp in the bag before the transition into night, so you're not scrambling to find it in the dark at an aid station.

• Black Diamond Spot 400 · full headlamp at the last daylight station 400 lumens, IPX8 waterproof, and runs on AAA batteries you can replace mid-race. The Spot 400 has a single-hand dimmer and a red night-vision mode. Battery powered is preferable to rechargeable for long efforts. You can swap batteries at a station rather than waiting for a charge.
• Backup AAA batteries · one full set per drop bag A headlamp dying at mile 75 in the dark is a serious safety issue. Fresh batteries at your last drop bag cost almost nothing.
• Small backup light or clip light (optional) A secondary clip light on your vest or pack can be useful for visibility to crew vehicles and course marshals at night crossings, independent of your primary headlamp.

Clothing & Layers

Temperature management is race-specific. In desert races like Javelina, nights get cold even when days are brutal. Mountain 100s like Hardrock can drop below freezing overnight. Check your race's historical weather and err toward having a layer you don't need rather than needing one you don't have.

• Wind shell or packable rain jacket At any station before a significant temperature drop or exposed ridgeline. Should weigh under 200g and pack into its own pocket. This is the layer that gets used most often in 100-milers.
• Long sleeve base layer For after sunset on mountain races or races at elevation. Merino blend for moisture management if you're going to be in it for hours.
• Lightweight gloves and buff/neck gaiter Hands and neck lose heat fast. Both pack to almost nothing. If your race involves any night miles above 5,000 feet, include them at the last station before dark.
• Change of shorts or shorts liner (optional) For chafing-prone runners or wet sections. Fresh liner shorts at mile 50 can make a significant comfort difference for the back half of a 100.

Pack by Segment, Not by Station

The biggest packing mistake is treating every drop bag as identical. Your early-race station needs something different than your night transition station. Think about what the next segment asks of you, then pack for that.

Common Mistakes to Avoid

• Packing the same bag for every station. Each drop bag should reflect the next segment, not the last one.
• Over-relying on aid station food. At mile 70 in the dark, the broth and boiled potatoes might be gone. Your own food in your bag is guaranteed.
• Not labeling bags clearly. Race volunteers handle hundreds of bags. Big name, bib number, and station name on the outside, in permanent marker, not on a tag.
• Skipping foot care to save time. Five minutes at mile 40 to tape a hot spot saves you an hour of hobbling at mile 70. The stop is worth it.
• Forgetting batteries. Your headlamp will die at the worst moment. Fresh batteries at the night station is non-negotiable.
• Packing your poles in a drop bag with no plan to carry them. Know in advance which station you're picking up poles at, and make sure that's not the same bag where you need to spend 10 minutes on foot care.

Bottom Line

A well-executed drop bag and crew system is invisible on race day. You get in, get what you need, and get out. A poorly planned one costs you 20 minutes of digging, sends you out of a station without what you needed, or leaves you in the dark at mile 70 while your crew waits at the wrong checkpoint.

Whether you're running solo on drop bags, working with a crew, or doing both, the same principle holds: plan for the segment ahead, not the one behind you. Prioritize foot care above everything else. Always include fresh batteries. And if you have crew, make sure they know exactly which stations they can access and what their job is at each one.

For major 100-milers, the Iron Miles Race Planner pre-loads which stations allow drop bags and which allow crew, calculates your arrival windows, and generates an interactive crew station map so your crew knows exactly where to go and when. Running a race that isn't pre-loaded? Upload a GPX file and the planner builds the same split-by-split view from your course file.