The spring classics are a six-week sprint. The Giro is a three-week war.

You’ve spent the last month and a half building punchy VO2max power for the Ardennes, sharpening 60-to-90-second efforts on the Cauberg and the Mur de Huy, maybe stretching to 3-5 minute threshold climbing for LBL. Your legs know what 130% FTP feels like for ninety seconds. They know what 110% feels like for four minutes. Sharp, punchy, explosive. Exactly what the spring demanded.

Then the Giro d’Italia opens May 8 in Nessebar, Bulgaria, and the Blockhaus shows up in week one asking for thirteen sustained minutes at threshold. Not ninety seconds. Not four minutes. Thirteen.

Different sport. And you have about twelve days to get ready for it.

Quick Summary: Giro d’Italia 2026

Detail	Info
Start	May 8, Nessebar, Bulgaria
Distance	3,459 km across 21 stages
Total climbing	~50,000m — one of the heaviest climbing Giros in memory
Key early climb	Blockhaus (Majella): 13.6km at 7.1% avg
ITT	Single long time trial stage
Transition window	LBL (April 26) to Giro climbing events: ~10-14 days

The amateur training lesson: Spring classics train efforts from 60 seconds to 5 minutes. Grand Tour climbing demands 8-20 minutes of sustained threshold power on grades that don’t relent. The gap between what you’ve been doing and what the mountains require is wider than you think — but twelve days is enough to bridge it if you train the right system.

Why the Blockhaus Changes Everything

The Blockhaus (Majella) is the first real mountain test. 13.6km at 7.1% average gradient. For a strong amateur, that’s somewhere between 8 and 14 minutes depending on your power-to-weight. Not a punch. Not a kick. A sustained, unbroken effort where pacing discipline matters more than peak power.

Think about what you’ve been training. The Mur de Huy is 1.3km. The Cauberg is under a minute at race pace. Even La Redoute at LBL tops out around four minutes for most amateurs. The Blockhaus is three to four La Redoutes stacked end-to-end, with no descent in the middle.

The power target drops. Instead of 120-135% FTP for a minute or 108% for four minutes, you’re looking at 95-105% FTP for 10-14 minutes. Right at threshold. Maybe just below. The effort feels deceptively manageable at minute two. By minute eight, your legs are filling with something thick and heavy that doesn’t clear between pedal strokes. By minute twelve, you’re bargaining with yourself about whether 92% FTP counts as “close enough.”

I ran into this wall two years ago. Came off a strong classics block, jumped into a local hill climb series in mid-May, and blew apart on a ten-minute climb I’d ridden comfortably in September. My FTP hadn’t changed. My ability to sit at FTP for ten consecutive minutes had eroded after six weeks of short, sharp work. The neuromuscular pattern was wrong. My body kept trying to punch and recover instead of settling into a rhythm and holding it.

What Sustained Climbing Actually Requires (That Punch Training Doesn’t Build)

How Is a 12-Minute Climb Different From a 4-Minute Climb?

The physiology shifts more than you’d expect:

1. Energy system blend: A 90-second effort at 130% FTP pulls heavily from anaerobic capacity. A 4-minute effort at 108% FTP sits at the VO2max-threshold border. A 12-minute effort at 98% FTP is almost entirely aerobic threshold work. You’re relying on fat oxidation, lactate clearance, and steady-state oxygen delivery — not the anaerobic reserves you’ve been sharpening all spring.

2. Pacing tolerance: On a 90-second climb, starting 10% too hard costs you maybe five seconds and some extra breathing. On a 12-minute climb, starting 10% too hard means you crack at minute seven and lose two minutes. The margin for error shrinks as duration extends. Pacing becomes a skill, not an afterthought.

3. Cadence demand: Classics climbing happens at 80-95rpm on steep, short pitches. Long mountain climbing at 6-8% gradient favors a slightly lower, steadier cadence — 75-85rpm for most amateurs — held for much longer. Your legs need to find a sustainable rhythm, not a surge pattern.

4. Mental model: Punch training teaches you to empty yourself and recover. Mountain climbing teaches you to hold back. To sit at an effort that feels moderate and trust that it will become hard enough at minute nine. That’s a fundamentally different psychological skill, and twelve days of practice helps more than you’d think.

The 10-14 Day Pivot

Liège-Bastogne-Liège wraps up April 26. If you’re targeting a May climbing event (a gran fondo, a local stage race, or just riding along with the Giro on Zwift), you have roughly two weeks. That’s not enough to build a new engine. But it’s enough to retune the one you have.

The good news: your spring classics base is deeper than you think. Months of structured work, long endurance rides, progressive overload, and all those recovery blocks you actually respected. You’re not starting from zero. You’re redirecting.

Workout 1: The Blockhaus Intervals

Your cornerstone session. This replaces whatever short VO2max repeats you’ve been doing.

Structure:

• Warm up 20 min, progressive to zone 3
• 3 x 10 minutes at 95-102% FTP, cadence 75-85rpm
• 5 minutes easy spinning between efforts
• Cool down 15 min

RPE: Effort one should feel like a controlled 7/10. You’re tempted to push harder. Don’t. Effort two: 7.5-8/10. Effort three: 8.5/10. If effort one feels like an eight, you’ve started too hard, and effort three will fall apart around minute seven.

What to track: Power consistency within each interval. You want less than a 5% drift from minute one to minute ten. If you see a steady fade — 285 watts at minute two, 265 by minute eight — your pacing instincts are still calibrated for short efforts. Start five watts lower next time.

The first time I did this after six weeks of classics intervals, I was bored at minute three and destroyed at minute eight. My legs had forgotten what “hold this for ten minutes” felt like. By the third session, I’d recalibrated. The effort felt different — less violent, more grinding, a slow build of fatigue instead of a sharp spike.

Workout 2: The Tempo Floor

This one doesn’t look hard on paper. It is.

Structure:

• 2 x 20 minutes at 88-93% FTP, cadence 78-85rpm
• 8 minutes easy between efforts
• Embed this in a 90-minute ride

RPE: 6.5-7/10. The kind of effort where you can breathe through your nose (mostly) and hold a choppy conversation. Not exciting. Not painful. Just… persistent.

Why this matters: Grand Tour climbing isn’t all threshold. The approaches, the valley roads, the early kilometers of a climb before the gradient bites. Those are ridden at high tempo. If you’ve spent six weeks doing intervals with full recovery between efforts, your ability to sustain 90% FTP for twenty minutes has likely decayed. This session rebuilds it.

Sweet spot training isn’t glamorous. But the riders who climb well for twenty minutes are the ones who can hold 90% FTP while their competitors’ power oscillates between 95% and 80%, wasting energy with every surge.

Workout 3: The Long Day With Late Climbing

Your weekend ride. The one that connects everything.

Structure:

• 3-4 hours total
• First 2.5 hours: zone 2 endurance. Fuel at 80-90g carbs per hour from the start.
• At hour 2.5: 10 min at 95-100% FTP (Blockhaus simulation)
• 15 min easy
• At hour 3: 10 min at max sustainable effort — whatever you can hold for the full duration without cracking
• Cool down for the remaining time

The rule: Your second 10-minute effort needs to be within 5% of the first. If it’s not, you went too hard on the first one, or you underfueled the early hours. Both are fixable.

This is the session that bridges classics fitness to climbing fitness. The long endurance base, the fueling practice, the pacing discipline, the sustained efforts on tired legs — that’s what a Giro stage feels like at the amateur level. Not a two-hour ride with sharp intervals. A four-hour day where the real work starts when you’re already tired.

A Two-Week Transition Plan

This assumes you finish LBL prep (or your own classics block) on April 26 and want climbing-ready legs by May 8. Eight to ten hours per week.

Week 1 (April 27 - May 3): Extend

• Monday: Rest. Completely. You just finished a six-week classics campaign. Sit on the couch.
• Tuesday: Easy 60-75 min. Zone 2. No intensity. Spin the legs out. This is a reset day, not a training day.
• Wednesday: Blockhaus Intervals — 3 x 10 min at 95-100% FTP
• Thursday: Rest or easy 45 min
• Friday: Tempo Floor — 2 x 20 min at 88-93% FTP
• Saturday: Long ride — 3.5 hours with 2 x 10 min sustained efforts in the final 90 min
• Sunday: Easy 60 min or rest

Week 2 (May 4 - May 8): Sharpen and Taper

• Monday: Blockhaus Intervals — 3 x 10 min, push to 98-105% FTP if week one held within 5% power consistency
• Tuesday: Rest
• Wednesday: 2 x 20 min at 90-95% FTP. Controlled. This is the last meaningful session.
• Thursday: Easy 45-min spin. 2 x 30-sec openers at threshold. Nothing more.
• Friday, May 8: Watch the Giro start. Or ride your own climbing event with legs that remember what sustained means.

The volume drops from week one to week two. That’s intentional. You’re not building fitness in fourteen days — you’re redirecting the fitness you already have and arriving fresh enough to use it.

The ITT Factor

Here’s something most classics-trained amateurs overlook: the Giro includes a single long individual time trial stage. And TT fitness draws from yet another energy system cocktail.

Time trialing at a competitive amateur level requires sustained power at 90-95% FTP for 30-60 minutes in an aerodynamic position. Your spring classics training — all those standing accelerations, high-torque surges, and recovery-and-repeat intervals — built none of that. The closest you came was the LBL simulation rides, and even those alternated between hard efforts and recovery.

If you care about the TT (and if you’re doing a local stage race, you should), add one session of 30 minutes continuous at 88-92% FTP in your aero position during week one. Just one. It’s not enough to build TT fitness from scratch, but it reminds your body what holding position under sustained load feels like. Your lower back will let you know how long it’s been since you spent thirty unbroken minutes in the drops.

Fueling for Longer Efforts

The caloric math shifts when efforts get longer.

A 90-second Cauberg punch burns maybe 25-30 calories. A 12-minute Blockhaus effort at threshold burns 180-220 calories. Multiply that by five or six major climbs in a single stage, add in the tempo approach work, and a Grand Tour stage day can burn 4,000-5,000 calories for an amateur.

You’ve (hopefully) been training your gut during the classics block. Keep doing it. The target stays at 80-90g carbs per hour, but the emphasis shifts. During classics-style racing, there are natural fueling windows on descents and flat connecting roads between climbs. During a Grand Tour mountain stage, the climb never fully stops. You’re eating while climbing. Practice that. Take a gel at minute five of your 10-minute intervals. Chew a bar while holding 95% FTP. It’s awkward. It’s necessary.

How to Watch the Giro Opening Week Like a Training Nerd

Four things to study:

1. Blockhaus pacing profiles. Watch who negative-splits the climb — starting conservatively and building power in the final 4km. Those riders have Grand Tour pacing instincts. Watch who goes hard early and fades. Those riders are still racing like it’s a classic.

2. The Bulgaria stages. The Giro starts in Nessebar — first time ever in Bulgaria. The opening stages will feature rolling terrain before the mountains hit. Watch which sprinters’ teams control the pace on early climbs. The power they set on 3-5 minute hills tells you what the peloton considers “manageable” sustained effort.

3. Cadence on long climbs vs. short ones. Pro riders shift cadence depending on gradient and duration. On a 2km Ardennes wall, they might spin at 90rpm. On a 13km Blockhaus, many settle into 78-82rpm. That’s the efficiency cadence for sustained climbing. Match it in your own training.

4. Who crashes in the ITT. Not literally. But watch whose power drops in the final third of the time trial. Riders who spent the spring racing classics often fade late in long TTs because they haven’t practiced unbroken sustained output. Sound familiar?

The Shift

Six weeks of classics training sharpened you. Made your punch faster, your recovery quicker, your ability to repeat short efforts more reliable than it’s been all year. That fitness isn’t wasted. The aerobic base underneath all those intervals is exactly what sustained climbing draws from.

But the top layer needs rewriting. Your legs learned to explode and recover. Now they need to learn to hold. To find a rhythm at 98% FTP and stay there while the clock runs past five minutes, past eight, past twelve. To resist the urge to surge. To trust that steady is fast.

Twelve days. Three key workouts. A philosophical shift from punching to patience.

The Blockhaus doesn’t care how fast you climbed the Cauberg. It cares whether you can hold 95% FTP for thirteen minutes without fading. Train that. Everything else you built this spring is the foundation. Now put a different roof on it.

---

Based on personal experience transitioning from classics-specific interval training to Grand Tour climbing demands. Giro d’Italia 2026 route details from the official Giro d’Italia site and stage profiles via ProCyclingStats. Find a climb that takes ten minutes at a hard, sustainable pace. Ride it three times. If the third time is within 5% of the first, you’re closer to ready than you think.