---
title: "Science Challenges & Habits | Harder"
meta:
description: "Explore science challenges and habit trackers on Harder. Build curiosity, stay consistent, and turn learning into daily action."
"og:description": "Explore science challenges and habit trackers on Harder. Build curiosity, stay consistent, and turn learning into daily action."
"og:title": "Science Challenges & Habits"
---
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# **Science**
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[**Sugar and Candy: Not Poison, But Most of Us Would Feel Better With Less**
Sugar isn't evil, but most people eat far more added sugar than they realize. Here's the science on sugary drinks, the myths (hyperactivity, addiction), and why your taste buds reset in weeks.](https://harder.pro/blog/added-sugar-candy-what-the-science-says.html)
[**Tea: The Calm-Alertness Habit (and the Great Matcha Squeeze of 2025)**
Tea is gently caffeinated, ritual-friendly and linked to a longer life. Here's the real science on green and black tea, the L-theanine calm-alertness effect, and the caveats worth knowing.](https://harder.pro/blog/tea-green-black-matcha-science.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)
[**Coffee: The Daily Habit That's Probably Fine (and Might Even Be Good for You)**
Coffee is one of the most-studied things you can drink, and the science is reassuring. Here's what the research says about the benefits, the safe dose, timing, and the myths worth retiring.](https://harder.pro/blog/coffee-caffeine-what-the-science-says.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)
[**The Science of Streaks: Why Tracking Your Progress Actually Works**
Tracking your progress is one of the most powerful behaviour-change tools ever measured. Here's the science of self-monitoring, streaks, and why 'don't break the chain' really works.](https://harder.pro/blog/why-tracking-your-progress-works.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)
[**How to Get Your First Pull-Up (Even If You Can't Do One Now)**
Only about 5% of women can do a strict pull-up - but it's a skill you build, not a gift you're born with. Here's the science-backed progression from dead hangs to your first rep.](https://harder.pro/blog/how-to-get-your-first-pull-up.html)