This Cyber Monday 2025 offer ended on 1 December 2025. Code THE5KRUNNER still gives 10% off Train Red sensors at Train Red. For current models and prices, including the new FYER PRO, see my Train Red review.
Train Red FYER 2.0, FYER PRO and PLUS 2.0
Muscle oxygen (SmO2) sensors for Garmin, Wahoo and Suunto. 10% off with code THE5KRUNNER.
Best Train Red Discount 2025 – Up to 30% Off (Cyber Monday Live)
★ The absolute best Train.Red discount right now is 30% off the full course ★
Ends Dec 1 – discount auto-applied at checkout
Full Train.Red Course
30% OFF – BEST DISCOUNT
Complete SmO2% training education
Train.Red FYER & PLUS are the most accurate consumer muscle oxygen (SmO2%) sensors available. Used daily by pros and serious athletes for warm-up optimisation, threshold testing, and recovery monitoring.
→ Shop All Train.Red Deals – Best Discounts Live
Offer ends Dec 1, 2025 • Prices include VAT • Free shipping over €100
Last Updated on 3 October 2026 by tfk the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID


