Hardest Marathons in the World

What Makes a Marathon Hard?

The hardest marathons typically feature significant elevation gain (often over 1,000m), hot or unpredictable weather, and challenging surfaces like trails or mixed terrain. These factors compound: a course with both steep hills and high temperatures will be exponentially harder than one with just one of these challenges.

Our difficulty algorithm quantifies the time impact of each factor. A marathon with a high difficulty score means your finish time will be significantly slower compared to a flat, cool, road marathon — even at the same effort level.

Preparing for a Difficult Marathon

• Train on hills that match the race profile
• Practise running in similar temperatures if possible
• Adjust your pace expectations using our difficulty calculator
• Consider trail shoes for mixed or trail-surface races

Use our marathon comparison tool to see exactly how much slower you should expect to run on these courses compared to a flat road marathon.