---
title: "Challenges - Harder | Harder"
meta:
description: "Guides, breakdowns and printables for structured challenges - the winter arc, 75 Hard, running and walking challenges, and how to actually finish what you start."
"og:description": "Guides, breakdowns and printables for structured challenges - the winter arc, 75 Hard, running and walking challenges, and how to actually finish what you start."
"og:title": "Challenges - Harder"
---
Harder - Home
# **Challenges**
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[**The Arc Setup Checklist**
A 20-point checklist for designing an arc challenge you finish - rules, floors, a failure condition, witnesses, and a dead-zone plan. Free printable, no email.](https://harder.pro/blog/arc-setup-checklist.html)
[**The Arc Tracker - 92 Days, One Box Per Day**
A free printable 92-day tracker for the winter arc: one box per action per day, a HELD column instead of a streak, in dated and undated versions. No email, no watermark.](https://harder.pro/blog/arc-tracker.html)
[**The Arc Challenge, Explained: Why Most Arcs Don't Finish**
An arc challenge is a fixed-length self-improvement run with rules you set yourself. Here's why self-designed arcs collapse - and what makes one actually finish.](https://harder.pro/blog/arc-challenge-explained.html)
[**7 Challenges You Can Actually Do With Friends (and Why That Makes You More Likely to Finish)**
The fastest way to finish a challenge is to not do it alone. Here are 7 genuinely popular challenges that are even better with friends - plus the science of why accountability works.](https://harder.pro/blog/challenges-to-do-with-friends.html)
[**75 Hard: What the Science Says About the Internet's Most Intense Challenge**
75 Hard bundles genuinely healthy habits inside rigid, non-individualised rules experts criticise. Here's what the science says about the no-rest and restart rules - and a smarter way to do it.](https://harder.pro/blog/75-hard-challenge-what-science-says.html)
[**The 6-6-6 Walking Challenge: Good Idea, Made-Up Numbers (Here's the Science)**
The viral 6-6-6 walking challenge has no scientific basis for its numbers - but the hour of brisk daily walking underneath is powerfully healthy. Here's what the research really says.](https://harder.pro/blog/6-6-6-walking-challenge-science.html)
[**Japanese Walking: The Viral Trend That's Actually Backed by 20 Years of Science**
Japanese walking (interval walking training) alternates 3 minutes brisk with 3 minutes slow. Here's the real science - aerobic capacity, strength and blood pressure gains - and how to start.](https://harder.pro/blog/japanese-walking-interval-training-science.html)
[**Couch to 5K: How to Start Running (and Why Your Body Will Thank You)**
Couch to 5K takes total beginners from the sofa to a 5km run in 9 weeks. Here's how the run/walk method works, the science on running's benefits, and how to start without getting hurt.](https://harder.pro/blog/couch-to-5k-how-to-start-running.html)