Data-driven guides on power training, training load, climb analysis, and periodization — written by cyclists, for cyclists.
Functional Threshold Power is the single most important number in data-driven cycling. Learn the 20-minute test, ramp test protocol, and how to apply your FTP to Coggan power zones.
Read Article →Understand the Banister impulse-response model that powers every serious cycling training platform. Learn how Chronic Training Load, Acute Training Load, and Training Stress Balance interact.
Read Article →VAM (Velocità Ascensionale Media) is the pro peloton's secret weapon for pacing mountains. Discover how to calculate your VAM, target values by fitness level, and why it beats speed or time.
Read Article →Discover the science behind safe weekly CTL ramp rates, why building fitness too fast leads to injury, and how to time your peak form for race day using the training stress balance.
Read Article →Calculate your power zones, W/kg ratio, and Coggan category ranking in seconds. No signup required.
Open Calculator →Drop your ride file. Scrub elevation in real-time. Calculate VAM, grade percentages, and climb categories instantly.
Analyze a Ride →Model your CTL, ATL, and TSB across a 12-week build, taper, or peak event. See your Sun Log heatmap live.
Model My Training →