Training with Xert Forecast AI (XFAI) – Knowledgebase

Xert Forecast AI (XFAI) is Xert's outcome-driven smart training plan generator. It looks at your current Fitness Signature, your current training loads, and a specific outcome you want to achieve — improving part of your power curve, preparing for an event, or replicating a past performance — then builds a forward-looking training plan to get you there, adapting as you execute it.

Best for: Athletes with a specific outcome in mind — a target fitness level, an upcoming event, or a specific race performance — who want a plan that adapts to their life rather than a rigid calendar.

In this guide: What XFAI is, how it builds your plan, the three program modes, how to follow and adjust your plan, and the most common questions from new users.

Quick Answers

XFAI builds a plan toward a specific outcome. Unlike XATA's day-by-day guidance, XFAI looks days, weeks, or months ahead to forecast the training you'll need.
You pick the outcome, XFAI builds the plan. Three modes — Goal, Event, and Race — cover different kinds of outcomes.
It uses your data. XFAI's predictions rely on your historical Xert data, so your plan is only as accurate as your Fitness Signature and training history.
You can still train your way. Each day gives you Low / High / Peak XSS targets, just like XATA, and you can hit them with structured workouts, free rides, Magic Buckets, or group rides.
Your plan adapts as you execute it. Skip a day, ride harder than planned, add a commute — click Adapt and XFAI rebuilds the rest of the plan.

What is XFAI?

Xert Forecast AI (XFAI) is Xert's outcome-driven training plan generator. It uses your historical data and training constraints to build a plan that projects forward, predicting the training you'll need to reach a specific outcome — and adapting as you execute it.

XFAI offers three program modes:

Goal — improve your fitness signature, optimized on a specific part of your power-duration curve
Event — prepare for the demands of an upcoming event based on its type, terrain, and estimated duration
Race — analyze a past performance (yours or someone else's) and train to replicate or improve on it

Note on accuracy: XFAI's forecasts are based on your historical data in Xert — including your Fitness Signature and training loads when each past breakthrough was achieved. The more accurate and up-to-date your historical data is, the better XFAI's predictions will be.

Before generating a plan, make sure your current Fitness Signature is accurate. If your signature is stale, consider getting a breakthrough first so XFAI starts from the right baseline.

What makes XFAI different from a traditional plan?

Most training plans have fixed workouts on fixed days, with fixed rest days. XFAI works differently:

It forecasts forward from where you are today. Instead of following a generic template, XFAI uses your current fitness and training load to build a plan specific to you.
It's outcome-driven. Every day of training is there to help you reach your target, not to fill a calendar.
It gives you daily targets, not fixed workouts. Like XATA, XFAI recommends Low/High/Peak XSS each day and lets you choose how to hit them.
It adapts as you execute it. Click Adapt at any time and XFAI rebuilds the remainder of the plan based on what you've actually done.

Key idea: XFAI is a plan that predicts the future and adjusts as reality changes — not a static template you follow until you fall off it.

How XFAI decides What to Recommend

XFAI looks at two categories of information when building your plan.

Rules XFAI always follows

No training on recovery days. If your projected Training Status is red, XFAI schedules recovery — no workout.
No high-intensity training on tired days. If your projected Training Status is yellow, XFAI schedules low-intensity endurance only.
Training must fit your availability. Each day's planned training stays within your daily hours and weekly maximums.

Settings you control

XFAI shapes the plan around several user-adjustable settings, covered in detail below:

Polarization level
Periodization
Recovery demands
XSS per hour preference
Training availability

Together, these let XFAI produce a plan that matches your outcome, your schedule, and how you prefer to train.

Related articles: Training Status (Form) • Training Availability • Recovery Demands • Polarization • Periodization

What Xert Recommends Each Day

Like XATA, XFAI gives you daily Low / High / Peak XSS targets rather than one prescribed workout:

Low XSS = aerobic/endurance strain (Threshold system)
High XSS = sustained harder work above threshold (HIE system)
Peak XSS = high-power/explosive strain (Peak Power system)

Each day in your forecast is labeled as Low Intensity, High Intensity, Recovery, or Rest:

Low Intensity days — ride easy, avoid high intensity. XFAI may schedule these to build your base or to hold back before a harder day.
High Intensity days — you're projected to be fresh enough for hard work. XFAI sets the target intensity needed to progress your high and peak training loads toward your target.
Recovery days — your status is projected to be red; take the day off or do something very light.
Rest days — days you don't need to train. Free time for other activities.

Why this matters: You can hit each day's targets with the ride you want to do. Following the XSS numbers is more important than following any specific workout.

How to use XFAI day-to-day

Step 1 — Generate your plan

From the Program tab, choose your XFAI mode (Goal, Event, or Race), set your target outcome and date, confirm your availability, and run the forecast. XFAI will build the plan and display its progress on screen as it works.

You'll see the full plan laid out day by day, with the expected training, training status, and projected fitness at each point. You can review it and confirm it makes sense before you start following it.

[Screenshot placeholder: Forecast AI plan on the planner]

For more specific help with creating a training plan, see this article:

Step 2 — Open the Today page

Each day, the Today page shows:

Your daily Low/High/Peak XSS targets
Your Training Status (readiness)
A list of Recommended Training options ranked by fit

This works the same way as XATA — the difference is that XFAI's recommendations are tied to a forward-looking plan with a specific outcome in mind.

Step 3 — Choose how you want to train today

You have the same three common approaches as XATA:

Option A: Do a structured workout Pick from the top recommended workouts. Send the workout to your trainer, head unit, or Xert EBC app.

Related articles: Sending Workouts with Xert

Option B: Do a free ride Don't want intervals? Ride however you want, keeping today's Low/High/Peak targets in mind. XFAI analyzes what you did and adapts the rest of the plan accordingly.

Related article: How to Analyze an Activity Using MPA

Option C: Use Magic Buckets Magic Buckets turns any ride into a guided session that helps you fill today's targets — without structured intervals.

Related articles: Magic Buckets Overview • Using Magic Buckets in Real Time

Planning and adjusting your plan with XFAI

Pinning workouts and adding activities

XFAI's biggest day-to-day power is its ability to work around your schedule:

Pin workouts you want to do on specific days (e.g., "I always do the hard ride on Saturday"). XFAI builds the plan around those.
Add other activities to the calendar — commutes, gym sessions, club rides — so XFAI accounts for the XSS they contribute.
Change your availability for specific days if your schedule shifts.

Once you've made changes, click the Adapt button. XFAI re-runs the forecast and updates the rest of the plan based on your changes.

Magenta Days: When A Plan Becomes Tight

If you see magenta outlines on your XSS matchsticks or Forecast Placeholder cards, XFAI has flagged a conflict with the plan for that day. A day is flagged in magenta when:

The day's estimated training exceeds your available time
High-intensity training is scheduled on a day you're projected to be tired (yellow status)
Any training is scheduled on a day you're projected to need recovery (red status)

Hover over a magenta day to see what's affecting the plan.

Often, clicking Adapt will find a revised plan that resolves the conflict. But if the plan has become too tight — too many missed days, too aggressive a target, too little time — XFAI may not be able to find a feasible plan, and you'll need to adjust your availability, soften your target, or push the target date out.

Checking your progress

XFAI's progress page shows how your fitness signature and training loads have changed so far, and what they're projected to do over the rest of the plan. Use the slider to navigate past and future dates.

Settings that Matter Most in XFAI

These settings control how XFAI shapes your plan. You can access them from the Program tab by selecting Modify Plan, and you can change them at any time.

Periodization Level — Controls how much "base" work you get early in the plan vs. higher-intensity work later. Higher periodization means more structured base-build-peak progression.
Polarization Level — Controls how strictly your training follows polarized (80/20) distribution. Higher polarization means more clearly separated easy days and hard days.
Recovery Demands — Adjusts how much recovery XFAI builds into your plan. Increase if you find you're typically more tired than Xert projects; decrease if you recover faster than expected.
XSS per Hour Preference — Controls how training-dense your plan is. Higher values pack more training into less time.
Max Weekly Hours — Caps the total training hours XFAI will schedule per week, regardless of availability.
Training Availability — Controls how much time you have to train each day of the week.

A note on Improvement Rate: Unlike XATA, XFAI doesn't use Improvement Rate directly. Instead, it schedules the training needed for each system (Low/High/Peak) to reach your target training loads by your target date — without training any system while it's tired.

Related articles: Periodization • Polarization • Recovery Demands • XSS Per Hour Preference • Training Availability

Common Onboarding Questions (FAQ)

"Why does my plan have so many high-intensity days back-to-back?"

XFAI treats any day with High or Peak XSS as a "high intensity" day, even if the amounts are relatively small. Click the XSS circles in the planner to see the specific Low/High/Peak values XFAI has forecast for each day — you may find the intensity is lower than the label suggests.

Depending on your settings (and recent activity) it's very common to see Xert spread your High & Peak training over multiple days, rather than trying to pack it all into a single ride/activity.

"Why does my plan have so many rest days?"

This is intentional - Xert differentiates between Rest days and Recovery days. XFAI schedules rest days when training isn't required to reach your target on time, & schedules recovery days when you're too fatigued to train & recovery is recommended.

If your target is achievable with fewer training days, XFAI won't add work that isn't required. You could try adjusting your program settings to increase your target.

Related article: Why does my Xert Forecast AI plan include so many rest days?

"Why was my training shorter (or longer) than the forecast predicted?"

XFAI's forecasted durations are estimates. The actual time varies based on the workout or ride you choose to fulfill each day's XSS targets.

Related article: Why was my training shorter or longer than the forecasted duration?

"What does the magenta bar on my planner mean?"

It means XFAI has flagged a conflict between your projected fitness on that day and what the plan requires. Hover over the bar for details, then click Adapt to let XFAI rework the plan. If Adapt can't find a solution, you may need to adjust your availability or target.

"How often should I adapt my plan?"

It's mostly personal preference. Here's the short version:

The red dot is the clear signal. When Xert flags something wrong with your plan (a magenta day, an issue the plan can't resolve on its own), the red dot appears. That's a good time to click Adapt.
Without the red dot, adapting isn't needed. You can adapt daily if you want the plan tightly synced to every ride, or weekly if you prefer a stable picture of the week ahead.
Early in a plan, adapting feels more volatile. What you do today has less material impact on a target that's months out, so small rides can cause noticeable shifts in the plan. This smooths out as you progress.
Late in a plan, wiggle room disappears. Near your target date — or on an already-tight plan — missing days becomes harder to recover from. Adapting more often helps you see problems earlier.

A common approach: Plan your week at the start of the week. Pin or swap workouts around races, group rides, and recurring commitments. Let the plan run through the week — minor deviations in workout length are fine. Re-assess and adapt at the end of the week before planning the next one. This gives you a stable picture of the week ahead while still letting XFAI adjust to reality.

"What happens if I skip training?"

XFAI will try to adapt the plan, but the flexibility has limits. If you miss enough days, you may no longer be able to reach your target by your target date — at which point XFAI will flag the issue or, in tight plans, be unable to build a valid forecast. Adjust your target date or availability if this happens.

"Do I need an FTP test?"

No. Xert updates your Fitness Signature from real ride data and maximal efforts. But XFAI's accuracy depends on your Fitness Signature being current — so if you haven't ridden hard in weeks, consider getting a breakthrough before generating a plan.

Related article: Do I need an FTP test to use Xert?

"My signature is stale — why doesn't XFAI schedule a breakthrough workout?"

Xert doesn't schedule breakthrough-specific workouts as part of your plan. It flags your signature as stale when it's been 3+ weeks since your last breakthrough, but it won't insert a breakthrough effort into the forecast automatically. You may occasionally see breakthrough-eligible workouts appear in your recommended list when your day's XSS targets align with them — but this is a byproduct of matching targets, not because XFAI is scheduling breakthroughs intentionally.

This is because Xert can keep your signature reasonably accurate even without regular breakthroughs — it estimates small changes to your Fitness Signature based on how your training loads (Low, High, Peak) are trending and how you've historically responded to each type of training. If you're training consistently, Xert assumes your fitness is moving in the right direction even without a fresh breakthrough.

That said, breakthroughs are still useful — especially to re-anchor your signature to what you can actually do right now. You have two options:

Stick with the forecast and let Xert estimate your signature changes. This is fine for most users in most phases of training.
Deliberately go after a breakthrough — a hard group ride, a race, or a breakthrough-oriented workout. Then click Adapt so XFAI updates the plan based on your new numbers.

Adding a breakthrough effort won't permanently disrupt your plan. XFAI will carry the updated fitness forward and rework the remaining schedule.

A low-disruption option: use a scheduled high-intensity day for a group ride or online race. You'll get a chance at a breakthrough while still hitting the day's XSS targets — combining race-level effort with Magic Buckets makes this especially efficient.

Key Takeaway

XFAI is built for athletes with a specific outcome in mind.

It predicts the training you'll need, adapts as you execute it, and gives you daily flexibility — but it's still working toward a target, so the choices you make each day either keep you on track or push the target out of reach.

Related Resources