Delo Velo.

Phases & methods explained

A goal-date plan is built from four sequential phases — what each one is for, working backwards from your event:

• Base. The foundation: mostly easy aerobic riding at high volume, building the aerobic engine everything else is built on. Low injury/illness risk, meant to be sustainable for weeks at a time. Fills whatever time is left before Build.
• Build. Structured intensity gets layered on top of the base — more threshold/sub-threshold work, developing the ability to sustain harder efforts for longer. Fixed at 4 weeks.
• Peak. The sharpening phase closest to the event: race-specific, harder efforts to prime top-end fitness. Fixed at 2 weeks.
• Taper. The final week: volume drops substantially while some intensity is kept, so fatigue dissipates and fitness/freshness peak on race day. Fixed at 1 week.

Each phase gets an aerobic/threshold/anaerobic percent target — how much of that phase's training time should land in each zone. The method you pick decides those percentages:

• Polarized-hybrid (default). Keeps threshold work minimal in every phase — like Polarized below — but raises the amount of genuinely hard (not just moderate) work as the event nears, instead of adding threshold. Sharpens race readiness without giving up "easy days easy."
• Polarized. A flat ~80/10/10 split held constant through every phase — minimal threshold ("grey zone") work at any point. The distribution most associated with elite endurance athletes in research on training intensity.
• Pyramidal. More threshold work than polarized, least high-intensity work of any method here — a broader base of moderate effort. Common among recreational and some elite athletes.
• Sweet-spot. Concentrates a large share of quality work near threshold (roughly 85-95% FTP) — time-efficient for lower weekly hours, but explicitly trades away the "easy days easy" principle the other methods protect.
• Traditional. Classic block periodization: raises both threshold and high-intensity work through Build and Peak. This was this app's only method before the others were added — pick it if you want the original behavior back.

Training terms

• TSS is training stress. Think of it as one number for how demanding a workout was. Duration and intensity both matter: a long easy ride and a short hard interval session can both create meaningful TSS in different ways.
• Daily load is your TSS for that day. On the main chart, each bar is the load from one day of training. Bigger bars mean more stress was added to your body on that date.
• ATL is short-term fatigue. ATL looks at roughly the last week, so it reacts quickly after hard training and drops quickly when you rest.
• Form, or TSB, is freshness. TSB is CTL minus ATL. Positive form usually means you are fresher; negative form usually means you are carrying training fatigue. A little negative form is normal during a build, while very negative form for several days is a warning sign.
• Load is useful, not moral. More TSS is not automatically better. The goal is the right stress at the right time: enough load to improve, enough recovery to absorb it, and enough easy training that hard sessions stay high quality.

Training guidelines

• Follow the 80/10/10 polarized split. Aim for roughly 80% of training time easy aerobic, ~10% threshold, ~10% anaerobic. Elite endurance athletes across sports consistently converge on this distribution.
• Make easy days genuinely easy. Most "grey zone" time comes from easy rides drifting too hard. Truly easy riding builds aerobic base with little fatigue cost, letting you absorb more total volume — the biggest long-term driver of endurance fitness.
• Make hard days genuinely hard. Concentrate intensity into 1–2 quality sessions per week (e.g. 4–5×4min VO2max intervals, or short sprint efforts) instead of spreading moderate effort across every ride.
• Keep ramp rate below ~8 CTL/week. Building fitness faster than that is associated with elevated injury and illness risk — the Ramp rate chart flags it in red.
• Train mostly in the −10 to −25 form range. That TSB band is productive load; dipping below −30 for days at a time is overtraining-risk territory, and staying above +5 for weeks means you're detraining.
• Periodize with blocks. Use the training blocks above: a base phase heavy on aerobic volume (e.g. 85/10/5), then a build phase with more threshold (e.g. 70/20/10), then a short taper. The balance panel judges you against the active block's target automatically.
• Respect recovery. Adaptations happen while resting, not while training. Plan a lighter week roughly every 3–4 weeks and let form climb back towards zero before the next build.