Aerobic Base Block — 6 Weeks
Six weeks of mostly easy aerobic volume with one weekly threshold session and one strength day, building the base that later interval work sits on.
- GOAL
- Endurance
- LEVEL
- Intermediate
- LENGTH
- 6 weeks
- SESSIONS
- 5 per week
This block builds aerobic capacity through volume, not intensity. It follows an off-season or a return from a race, and it deliberately sits before any VO2max or race-specific work — going hard before this base exists is the most common way endurance athletes stall. Weeks 1 to 3 establish the weekly rhythm at a fixed volume; weeks 4 to 6 add duration to the long session and move the threshold work earlier in the week. Roughly 80 percent of the weekly time is easy and it should feel almost too easy. It sets up an interval or race-preparation block, where the sharpening happens.
- →Runners and cyclists returning to structured training after a break or a race
- →Anyone whose training has drifted into all sessions being moderately hard
- →Athletes preparing for a race that is 10 or more weeks away
- →People who can commit five days a week including one long weekend session
- →Able to run or ride continuously for 45 minutes at a conversational pace
- →A known aerobic pace or heart-rate ceiling — a recent field test or a lactate threshold estimate
- →At least three months of consistent aerobic training in the last year
- →No current lower-limb injury that changes your gait
Establish a repeatable five-day week at a fixed volume, with almost all of it easy. The goal of these three weeks is consistency, not progress.
- MondayAerobic Base SessionEasy. Heart rate below 75 percent throughout.
- TuesdayFull Body StrengthTwo sets per lift. Legs must recover by Friday.
- WednesdayAerobic Base SessionSame as Monday. Do not race yourself.
- ThursdayRestOr a 20 min walk if you are stiff.
- FridayTempo and ThresholdThe only hard session of the week. Keep it controlled.
- SaturdayAerobic Base SessionThe long one. Add all weekly volume increases here.
- SundayEasy 30 min walk, optional
PROGRESSIONHold weekly volume constant across weeks 1 and 2, then add 10 percent in week 3, all of it in the Saturday long session. Easy sessions stay below 75 percent of max heart rate — if you cannot hold a conversation, slow down regardless of pace. The Friday threshold session stays at the same duration all three weeks.
Extend the long session and move the threshold work to midweek so it sits further from the long day. Easy volume rises; intensity does not.
- MondayAerobic Base SessionEasy. Recovery from the long session.
- TuesdayFull Body StrengthSame two sets. Load can rise if Friday is unaffected.
- WednesdayTempo and ThresholdMoved earlier so the long day sits further away.
- ThursdayEasy 30 min walk
- FridayAerobic Base SessionStrictly easy. Do not carry Wednesday's intensity into it.
- SaturdayAerobic Base SessionLongest session of the week. Fuel it.
- SundayRest, or 20 min walk
PROGRESSIONAdd 10 percent to weekly volume in weeks 4 and 5, all of it in the Saturday long session, then cut total volume by 30 percent in week 6 as a down week. Threshold duration extends by 5 minutes per week for weeks 4 and 5 only. If resting heart rate is more than 7 beats above your baseline on two consecutive mornings, take the day as a walk.
- →Weekly volume rises no more than 10 percent, and every increase goes into the long session, never spread across easy days.
- →Week 6 is a down week: cut total volume by 30 percent and keep the session count at five.
- →Roughly 80 percent of weekly training time stays easy. One hard session per week is the ceiling for this block.
- →If a week is missed entirely, restart at the previous week's volume rather than picking up where the plan says.
- →Strength work stays at two sets per lift throughout. It is there to maintain, not to build.
- →Resting heart rate more than 7 beats above baseline for two mornings running means the next session becomes a walk.
- →2 km time trial on a track or treadmill, at the start and end of the block
- →30-minute time trial to estimate threshold pace and heart rate, at the start and end
- →Average heart rate for a fixed 40-minute easy session at a fixed pace, compared week to week
- →Morning resting heart rate, taken daily
- →Body weight, taken on the same morning each week