NutritionLevel 2Guide
Race Day Nutrition: What the Research Recommends
A complete, research-backed guide to race day nutrition for endurance athletes: how to carb load, what to eat for breakfast, and how to fuel mid-race.
Read the guide · 3 minTraining for your first half marathon, marathon or 70.3
Stop guessing. Start training on evidence.
HI turns peer-reviewed research on training, fueling and recovery into three things you can actually do this week. Free to read, every claim sourced, zero affiliate links.
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172 sources in the research library0 affiliate links, everEvery claim graded: strong, mixed or early
Do this week
3 things you can do
this week.
See all protocols →01Recovery
Sleep 8 hours, 3 nights in a row
Sleep extension produces measurable performance gains within 72 hours: reaction time, sprint speed, and mood all improve.
Strong evidenceRead Sleep Extension Protocols →
02Motion
Do one Zone 2 session this week (30–45 min)
Zone 2 training builds your aerobic base, the foundation for all other fitness. Most people skip it because it feels too easy.
Strong evidenceRead Zone 2 Reality Check →
03Nutrition
Eat 20–40g protein within 2 hours post-training
The post-exercise window is real, though more flexible than once believed. Protein timing supports muscle protein synthesis when total intake is adequate.
Mixed evidenceRead Fuel During Training →
Getting started
From information overload to race-day clarity.
Step 1
📖
Learn
Follow a Learning Trail built for endurance athletes. Zone 2, periodization, sleep for performance, race fueling: each trail takes you from first principles to race-day application, level by level.
Step 2
⚡
Track
Health IQ is your score for how much evidence-based training knowledge you have actually banked. Every article you finish adds to it, so you can see what you have covered and what you have not.
Step 3
🎯
Apply on race day
Turn the evidence into your actual race plan: what to run, what to eat, when to rest. When you're ready for personalised support, HI Programs meet you at your training stage.
Four pillars
Four areas that determine your race result.
🏃
Motion
Zone 2, VO₂ max, periodization and race-specific strength.
See the Motion evidence →🥗
Nutrition
Carbohydrate periodization, protein timing and race-week eating.
See the Nutrition evidence →😴
Recovery
Sleep quality, HRV and the active recovery that actually works.
See the Recovery evidence →🧠
Mindset
Pre-race anxiety, motivation and the psychology of a first finish line.
See the Mindset evidence →Latest articles
Research into action
How we read the research
Every claim on HI follows the same four steps. When the evidence is thin or conflicting, we say so.
Written by Filip Berggren, founder of HI. I read the studies, check the data, and tell you when the evidence is thin.
See how we work with evidence01
Find the research
Peer-reviewed studies, meta-analyses and RCTs, preferably from the last 5 years.
02
Evaluate the evidence
Sample sizes, methodology, conflicts of interest, convergence across studies.
03
Translate to practice
Findings become clear, actionable steps. No jargon, no gatekeeping.
04
Show the sources
Every claim links to research. Limitations stated clearly. Always.
Path by HI is the app that turns this into your plan. Closed beta.
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