Global Training Shoes Market Size, Share & Demand Report By Product Type (Cross-Training Shoes, Strength & Weightlifting Shoes, HIIT & Functional Training Shoes, Studio & Indoor Training Shoes, Outdoor Training Shoes), By End-Use (Fitness Enthusiasts, Professional Athletes, Sports Academies, Military & Law Enforcement, Lifestyle Users), By Distribution Channel, By Price Range, By Gender, By Region & Segment Forecasts, 2026–2031