1. Physiology - Cardiovascular system - Respiratory efficiency - Muscle fiber types (slow-twitch, fast-twitch) - VO₂ max - Lactate threshold 2. Performance - Distance categories (5K, 10K, half-marathon, marathon, ultramarathon) - Pace (min/km or min/mile) - Heart rate zones - Time trials - Personal records (PRs) 3. Technique - Foot strike (heel, midfoot, forefoot) - Stride length and cadence - Arm swing - Posture - Gait analysis 4. Equipment - Running shoes (road, trail, barefoot) - Compression gear - Smartwatches / GPS trackers - Running apps - Reflective gear 5. Environment - Road, trail, track, treadmill - Elevation (hill running) - Weather (temperature, humidity, wind) - Altitude training 6. Psychology - Flow state - Motivation - Mindfulness in motion - Goal-setting - Running therapy 7. Training - Base building - Interval training - Tempo runs - Long runs - Recovery protocols (foam rolling, ice baths) 8. Health & Injury - Runner's knee, shin splints, IT band syndrome - Injury prevention - Overtraining - Benefits (cardio health, mood improvement) - Medical clearance 9. Nutrition - Pre-run fueling - Electrolytes - Glycogen stores - Hydration strategies - Recovery nutrition 10. Purpose - Competitive running (track, road races, cross-country) - Recreational running - Weight loss - Mental health - Spiritual practice (e.g., meditative running) 11. Community & Culture - Running clubs - Parkrun - Major marathons (e.g., Boston, Berlin) - History of running (e.g., Pheidippides, barefoot running) - Virtual races & challenges