PROTR Journal

Training, nutrition
and performance.

Evidence-based guides for athletes who take their training seriously.

Training Science6 min read

What Is TSS? The Training Stress Score Explained for Athletes

TSS (Training Stress Score) is the single number that tells you how hard a workout was. Learn how it is calculated, why it matters, and how to use it to structure your training.

3 May 2026Read →
Nutrition7 min read

How to Track Macros for Athletes: A Practical Guide

Macro tracking is one of the highest-leverage habits for athletic performance. This guide explains what macros are, how much you need, and how to track them without making it a full-time job.

3 May 2026Read →
Strength Training5 min read

Progressive Overload: The One Principle Behind Every Strength Gain

Progressive overload is the foundational principle of strength training. This guide explains what it is, how to apply it safely, and how to track it automatically.

3 May 2026Read →
Endurance5 min read

Zone 2 Training: What It Is and How to Do It Right

Zone 2 training is where elite athletes spend 80% of their time. Learn how to define it correctly, find your Zone 2 heart rate, and apply it.

3 May 2026Read →