100K Ultra Marathon Races

The ultimate day-long challenge. Browse 100K races worldwide.

Xtrail Kenting by UTMB®

International105km

Grindstone Running Festival

International105km

Desert RATS Trail Running Festival

International105km

Speedgoat

International105km

Trail of the Kings - Lake Toba

International105km

Malaysia Ultra-Trail

International105km

Restonica Trail

International110km

Ultra-Trail Australia

International105km

Snowbasin

International105km

mozart 100

International119km

Trail 100 Andorra by UTMB® | Every trail tells a story in Andorra

International105km

Tenerife Bluetrail by UTMB®

International110km

Ultra-Trail Great Wall by UTMB®

International105km

Boréalys Mont-Tremblant by UTMB | New Ultra-Trail in Québec

International105km

Kaçkar

International105km

Wildstrubel

International113km

Puerto Vallarta by UTMB®

International105km

Ultra-Trail Shudao by UTMB®

International105km

Istria 100

International105km

Gauja Trail

International105km

Rothrock

International105km

Ultra-Trail Xiamen by UTMB®

International105km

Kaga Spa Trail Endurance 100

International105km

Bucovina Ultra Rocks

*114km

Paraty Brazil

International108km

Arc of Attrition

International105km

Quito Trail by UTMB®

International105km

TransLantau™ by UTMB® 116K

International116km

Patagonia Bariloche 105K

International105km

Patagonia Bariloche 100K

International100km

Istria 100 100K

International100km

Monterosa Walserwaeg 105K

International105km

Ultra-Trail Snowdonia 100K

International100km

Trail Verbier St Bernard 100K

International100km

Arc of Attrition 100K

International100km

Trail du Saint-Jacques 105K

International105km

HOKA UTMB Mont-Blanc 105K

International105km

Oh Meu Deus 105K

International105km

Oh Meu Deus 100K

International100km

Tenerife Bluetrail by UTMB® 100K

International100km

Kaçkar 100K

International100km

Ultra-Trail Australia 100K

International100km

Tarawera Ultra-Trail 100K

International100km

Speedgoat 100K

International100km

Ultra-Trail Kosciuszko 102K

International102km

Chihuahua by UTMB® 100K

International100km

Ultra-Trail Australia 101K

International101km

Ultra-Trail Mogan by UTMB® 100K

International100km

Chiangmai Thailand 100K

International100km

Chihuahua by UTMB® 105K

International105km

Puerto Vallarta by UTMB® 100K

International100km

AMAZEAN JUNGLE THAILAND 100K

International100km

The Canyons Endurance Runs 105K

International105km

Oman 100K

International100km

TransJeju 100K

International100km

Snowbasin 100K

International100km

TransJeju 104K

International104km

Ultra-Trail Kosciuszko 105K

International105km

Julian Alps Trail Run by UTMB | Discover the magnificent world of Julian Alps! 100K

International100km

HOKA Val d'Aran by UTMB® 105K

International105km

Torrencial Chile 100K

International100km

HOKA Val d'Aran by UTMB® 100K

International100km

Puglia 105K

International105km

Tenerife Bluetrail by UTMB® 105K

International105km

Paraty Brazil 105K

International105km

Ultra-Trail Mount Yun by UTMB® 105K

International105km

Paraty Brazil 100K

International100km

Welcome to the Eiger Ultra Trail 101K

International101km

La Sportiva Lavaredo Ultra Trail 105K

International105km

Grand Raid Ventoux 100K

International100km

Zugspitz Ultra Trail 107K

International107km

Trail Alsace 105K

International105km

KAT100 105K

International105km

La Sportiva Lavaredo Ultra Trail 100K

International100km

Zugspitz Ultra Trail 105K

International105km

Grindstone Running Festival 100K

International100km

Trail Alsace 109K

International109km

Restonica Trail 105K

International105km

Zugspitz Ultra Trail 100K

International100km

HOKA UTMB Mont-Blanc 101K

International101km

Bucovina Ultra Rocks 105K

*105km

Restonica Trail 100K

International100km

Trail 100 Andorra by UTMB® | Every trail tells a story in Andorra 100K

International100km

The Canyons Endurance Runs 100K

International100km

HOKA UTMB Mont-Blanc 100K

International100km

Julian Alps Trail Run by UTMB | Discover the magnificent world of Julian Alps! 105K

International105km

Madeira Island Ultra Trail

Portugal115km7,200m D+

Ultra-Trail Australia

Australia100km4,400m D+

Vibram Hong Kong 100 by UTMB

Hong Kong103km4,500m D+

TOR100 - Cervino Monte Bianco

Italy100km8,000m D+

Ultra-Trail Cape Town

South Africa100km4,300m D+

Ultra-Trail Côte d'Azur

France106km5,600m D+

Grand Trail Courmayeur

Italy100km6,500m D+

Ultra-Trail Australia (UTA)

Australia100km4,400m D+

Ultra Pirineu

Spain100km6,200m D+

MIUT (Madeira Island Ultra Trail)

Portugal115km7,200m D+

Tarawera Ultramarathon

New Zealand102km2,100m D+

Ultra-Trail Cape Town (UTCT)

South Africa100km4,300m D+

TORX Shenzhen

China100km5,000m D+

How to Train for a 100K

The 100K (62 miles) is a full day on your feet. Training builds to 80-100km per week with long runs of 40-50km. The biggest challenge isn't fitness — it's managing nutrition, fatigue, and mental lows across 12-20 hours.

Back-to-Back Long Runs

The signature ultra training method: a long run Saturday (30-40km) followed by a medium run Sunday (15-25km). This simulates running on tired legs without the injury risk of a single massive run.

Night Running

Many 100Ks require running through the night. Practice at least 2-3 night runs during training. Your headlamp, layers, and mental strategies need testing.

Crew & Drop Bags

Plan your race logistics: what goes in each drop bag, what your crew will have ready. Practice changing shoes, socks, and layering mid-run.

The Dark Patch

Between hours 8-14, you'll likely hit a low. Eat something salty, walk for 10 minutes, and remember: lows always pass. Don't make quitting decisions during a low.

Frequently Asked Questions

How long does a 100K take?

12-20 hours for most runners. Elite runners finish in 8-10 hours. Cutoffs are typically 20-24 hours.

Do I need to run 100K in training?

No. Peak long run is typically 50-60km or 5-6 hours. The race itself is the longest run. Your body adapts during taper.

Get a Personalized 100K Training Plan

UltraCoach builds an AI-powered plan tailored to your fitness, schedule, and race goals. It adapts as you train.