Training Philosophy: Building the Foundation

The Foundation: Why Your Base Is Everything

We've all heard about building a foundation in training. It's the base that keeps you at a stable athletic level — the platform that prevents you from falling far when you get sick, injured, or take a break. With a solid foundation, your body responds well to training when you build form, and you can reach a higher level.

The difference between a strong and weak foundation shows clearly over a full season. With a good base, you hold form longer, tolerate more training, and come back faster after breaks. Without it, your form collapses quickly if anything interrupts your training plan. You have to be well-trained to train well — that's the fundamental rule.

The question is: how do you build this foundation most effectively? Through a combination of sweetspot, zone 2, and year-round intensity work at reduced dose. Even in winter, the weekly structure includes both a VO2max session and a threshold session — just at lower volume than in season. This keeps the cardiovascular ceiling high while the aerobic base grows beneath it.

Sweetspot + Zone 2: The Combination That Builds Base

We've trained a combination of sweetspot, volume, and zone 2 with good results to build a solid training base. Sweetspot training (85–90% of threshold) is intense enough to produce good training adaptations, but low enough that the body can tolerate long interval sessions. It trains lactate oxidation — the body learns to use lactate as fuel, not just produce it.

Zone 2 (64–70% of FTP) focuses on fat oxidation and aerobic capacity. It's 'fake volume' — you get many of the benefits of long easy training, but in fewer hours. The motto is: it's better with more time at slightly lower intensity than the opposite. Zone 2 matches the intensity you ride at during most of a race, so making that effort feel easier is directly performance-enhancing.

How the combination works

Sweetspot (85–90% FTP): Long intervals (8–15+ min) that train lactate oxidation and improve aerobic properties in the muscles. Lactate around 1.5–2.5 mmol/L.
Zone 2 (64–70% FTP): Easy volume training that builds fat oxidation, capillary density, and mitochondrial capacity. Hallmark: you can talk comfortably.
Together they build the foundation without creating an early peak — you become aerobically strong without getting worn down by too much high intensity too early.

After periods with this combination, you'll notice sweetspot intervals getting easier, sessions can become longer, and you recover better between training days. That's the sign the foundation is being built.

Lactate Is Fuel, Not Waste

Historically, we learned in school that lactate is a waste product during hard exercise. But actually, lactate is fuel. Lactate oxidation provides energy to the muscles when we're below threshold. This insight changes how we should think about training.

Both fat and lactate are broken down and provide energy through the Krebs cycle — the central energy production in the mitochondria. The difference is that fat takes longer to break down, while lactate is more quickly available. Below threshold, the body uses both. Above threshold, lactate is produced faster than it can be burned, and that's when you 'go into the red.'

Research shows that zone 2 training increases MCT1 transporters (which carry lactate into the mitochondria) by 23–90%. This means your body becomes better at using lactate as an energy source. Sweetspot training pushes this process harder — you produce moderate lactate and train the system that consumes it. Together, they make you a more efficient machine.

The Fixed Flexible Week

A good weekly structure is half the job of a good training program. The fixed week must be flexible enough to work with your job and life. The point is to plan the structure — not the specific content. Exercises can vary week to week, but the framework stays the same.

Core principles

2 hard interval sessions per week, each with a rest or easy day before
5 quality sessions per week with 2 rest/very easy days
Most volume on the weekend (when time allows)
2 rest days provide proper recovery between hard sessions
1 zone 2 session mid-week for extra quality without major recovery demands

The ideal structure: Monday rest. Tuesday–Wednesday training block with first hard interval. Thursday rest. Friday–Sunday training block with second hard interval plus long ride/zone 2. But the point is flexibility — if Wednesday doesn't work, shift the pattern. The key is maintaining 2–3 days between hard sessions and protecting rest days before intervals.

Does training feel unnecessarily hard? Maybe the structure is wrong. Many cyclists ride easy sessions too hard and hard sessions too easy. The result is everything becomes 'medium' — you never properly recover and never get enough intensity to develop. The fixed flexible week solves this by clearly separating hard from easy.

The Feeling of Good Form — and Poor Form

The numbers on the power meter only tell half the story. The real test is how training feels in your body. Here's what to look for — signs that tell you whether the foundation is holding up.

Signs of good form

Energy to handle lots of training — long sessions don't drain you
Long intervals feel easy at the start, and you can maintain quality throughout
Strong in the legs — easy to produce watts over threshold even when tired
Recover well between sessions, feel good the day after hard intervals
Body doesn't resist — it feels hard for the legs, but not heavy for the body

Signs of poor form

Tired even on easy rides — you have to fight even at low intensity
Get hungry early in training sessions, energy runs out fast
Legs resist as soon as watts go up toward zone 3
Hills feel steeper than they are — everything feels heavy
Low energy level overall, feeling a bit flat and tired

Common causes of poor form despite regular training: too many hard intervals without enough easy volume, easy sessions at too high intensity (you never recover), poor nutrition, or simply too little training. The foundation approach with sweetspot + zone 2 addresses several of these problems at once.

Training Zones and What They Do

Each training zone has a specific purpose. The problem arises when everything gets mixed together in a gray middle zone where you're neither building base nor developing top-end speed. Here's what each zone actually trains, and when it's used in a well-structured program.

The zones and their functions

Zone 1–2 (endurance): Fat oxidation, lactate oxidation, general aerobic capacity. Conversational pace, 60–240 min. The foundation for everything else.
Sweetspot/Zone 3 (85–90% FTP): Lactate oxidation under high training load. Long intervals (8–15+ min) that build aerobic properties in the muscles.
Threshold/Zone 4 (95–105% FTP): Pushes lactate threshold higher. Long efforts (3–4 × 15 min) or short efforts (10 × 4 min).
VO2max/Zone 5 (106–120% FTP): Improves maximum oxygen uptake. Short, very hard intervals (4–6 min).
Neuromuscular/Sprint: Very short maximal efforts (10–30 sec). Peak power and coordination.

The most important thing to understand is intensity distribution. Research on elite athletes consistently shows that 75–90% of training time should be low intensity (zone 1–2), with 10–25% high intensity (zone 4–5). The middle zone — the gray zone — produces the least development per unit of recovery cost.

You don't need formal FTP tests to find your zones. Do a controlled hard session like 4 × 12 min — hard, but controlled. You should be able to do one more interval at similar quality. FTP is roughly average watts × 0.95. Don't overestimate — a too-high FTP turns your zone 2 into zone 3, and then the whole point of easy training disappears.

Seasonal Planning: From Winter Base to Summer Form

The weekly structure stays the same year-round: 2 hard sessions (one VO2max, one threshold) plus zone 2 volume. What changes through the season is the dose within those sessions. Winter means shorter intervals at reduced intensity — 3x3min VO2max instead of 6x4min, 2x10min threshold instead of 3x15min. Fewer total hours (15–20 hrs/week) but with consistent structure. Strength pedaling and cross-training supplement bike hours.

As the season approaches, the dose increases gradually. Intervals get longer, sets multiply, and total volume grows (23–28 hrs/week in season). More of the easy volume comes from long rides and races in zone 1. The ratio of low intensity to high intensity adjusts from 85–90% low in winter to 75–80% low in season — but the two hard sessions are always there.

This 'modulate dose, not type' approach avoids an early peak while keeping you race-ready year-round. You never have to rebuild the cardiovascular ceiling from scratch because you never abandoned it. A strong aerobic foundation plus year-round intensity delivers lasting performance through the entire season. See our training programs for concrete weekly plans.

Go Deeper

This page gives you the framework. For detailed plans, the full science, and week-by-week guidance — explore our articles.

Explore further

Training isn't about finding the perfect plan — it's about building a system that works with your life, week after week, year after year. Start with the foundation.