Every rule the plan engine uses, with the primary source behind it. When we are stricter than the source, we say so.
Start at Push. Each flag drops one level; two or more flags means Recover. Flags: last night under 6 hours; 3-night average under 7; energy Drained or Low, or soreness High or Wrecked; yesterday's effort 8+/10 or load over twice the 28-day daily average.
Our synthesis. Sleep thresholds follow the consensus that under 6 hours impairs next-day function; the 3-night average captures accumulated debt.
Nothing with caffeine within 9 hours of bed.
Gardiner et al. 2023: caffeine's half-life averages ~5 hours with wide individual variation; about 8.8 hours for a standard coffee to clear enough not to disturb sleep, 13.2 hours for a pre-workout dose. We round to 9 as a practical rule.
Hard sessions are scheduled to finish at least 90 minutes before bedtime.
Stutz et al. 2019 (meta-analysis): vigorous evening exercise ending within 1 hour of bedtime impairs sleep; ending earlier does not. We use 90 minutes as a conservative margin.
No hard work for a muscle group trained hard in the last 48 hours. The plan rotates to the least recently trained group in your split.
Garber et al. 2011, ACSM position stand on exercise for healthy adults: allow 48 hours between sessions stressing the same muscle groups.
We compare the US AQI sub-indices for PM2.5 and ozone and act on whichever is higher. PM2.5 over 100 moves hard sessions indoors for people with asthma, heart or lung conditions, or age 65+. Ozone over 100 moves hard sessions to the morning or indoors for everyone. Over 150, everyone's hard sessions go indoors. Over 200, everything goes indoors.
EPA AirNow activity guidance. Plain EPA wording for 101 to 150: "Sensitive groups should reduce prolonged or heavy exertion." Note: EPA counts people active outdoors as sensitive to ozone, which is why the ozone rule applies to everyone. Our indoor/morning moves at just over 100 are stricter than the guidance by design.
We use feels-like temperature from the hourly forecast and move training to the coolest free hour when the heat index hits 90F.
National Weather Service heat index chart and heat safety guidance.
Wind chill -18F or colder, or thunderstorms: indoors. UV index 8+: avoid 10am to 4pm outdoors. Pollen index 4-5 with a flagged allergy: indoors.
National Weather Service wind chill chart; EPA UV Index guidance (8+ is "very high"); Google's Universal Pollen Index (4-5 is high/very high).
150 to 300 minutes of moderate activity (or 75 to 150 vigorous; vigorous minutes count double), plus strength work on 2 or more days.
World Health Organization 2020 physical activity guidelines.
If you train before noon, eat 1 to 3 hours before. 20 to 40 g of protein in your next meal after training; daily total matters most. Finish dinner 3 hours before bed; a big meal close to bed can disturb sleep and bring on reflux.
Our synthesis of sports-nutrition consensus: pre-exercise meal timing, post-exercise protein dose ranges, and the sleep literature on late heavy meals and reflux.
Training load from time in HR zones (Edwards TRIMP): zone weights 1-5 for 50-60% through 90-100% of max HR.
Edwards training impulse method; max HR formula 208 - 0.7 x age (Tanaka et al. 2001).
Baselines use 14 days of history. Apple Watch reports SDNN, Fitbit reports rMSSD; we never mix the two in one baseline.
Our methodology. The metrics are not interchangeable, so mixing them would corrupt the baseline.
Cadence is not a medical device and gives no medical advice. These rules inform timing, not diagnosis. If you have a condition, check with your clinician.