WattsUP continuously models Chronic Training Load (CTL), Acute Training Load (ATL), and Training Stress Balance (TSB) across your indoor sessions and outdoor rides. Discover how to balance overload and recovery using safe CTL ramp rates.
CTL tracks your accumulated cardiovascular and muscular conditioning using a 42-day rolling exponentially weighted average. A weekend rider typically sits at a CTL of 40–50, while competitive amateurs prepare for target Gran Fondos at 80–110.
Read our complete scientific breakdown on how CTL, ATL, and TSB interact.
Using a 7-day decay rate, ATL reflects your immediate physiological exhaustion. A massive weekend training camp spikes ATL rapidly, temporarily depressing your ability to express raw threshold power.
Balancing ATL through structured 3:1 build-to-recovery blocks prevents overtraining syndrome, hormonal depletion, and musculoskeletal overuse injuries.
TSB is the simple difference: CTL minus ATL. When TSB is negative (−10 to −25), your body is in a state of productive training adaptation. When TSB rebounds into positive territory (+10 to +25) after a taper, you reach peak race day form.
Simulate different weekly build rates and discover your personal limit in our safe CTL ramp rates guide.
Accurate TSS scores require calibrated threshold power. Calculate your FTP and 7 Coggan power zones.
Open Calculator →Drop ride files to calculate normalized power, segment climbs, and inspect grade-by-grade VAM vertical speed.
Analyze a Ride →Learn how much weekly fitness you can safely build before fatigue causes injury or illness.
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