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The Best Interval Training Sessions for Cyclists – How, When & Why To Do Them

In this post I break down how and when to do the sessions discussed with Tristan above.

Structured Interval Training: A Periodised Approach

What separates effective training from junk miles is structure: the right sessions, in the right sequence, at the right time in your season. Below, I break down each session with specific power targets, cadence prescriptions, and progression protocols—adapted for competitive cyclists at any level.

Before You Get Started

Do I need a power meter?
While these sessions are best done with a power meter, you can also use heart rate (HR) or a rating of perceived exertion (RPE) to complete this training.

If you don’t use a power meter, be aware that both HR and RPE are likely to be influenced by external factors such as weather and levels of fatigue. Similarly, RPE and HR will increase during longer efforts as fatigue accumulates.
Can I do these sessions indoors?
Indoor is a time efficient option and some athletes find prescribed sessions easier to complete on a trainer, however riding outside adds specificity. What does this mean? You are riding in conditions that more accurately reflect your goal events.

If goal events require technical skills, such as MTB, gravel racing or bunch riding, then it is recommended to train in these situations as much as possible.
How many hard sessions per week?
If you’re starting out, we recommend the 80/20 rule, where 80% of your training is easy and 20% is hard. Practically, this translates to two hard sessions per week.

If you are a well-trained athlete, at the end of a specific training block, you can consider adding a third hard session.

Leave enough recovery time (around 3 days) between the more intense sessions to maximise training stimulus and avoid overtraining.
How do I calculate my FTP?
Traditional Method: 20-minute all-out effort after proper warm-up. Multiply your average power by 0.95 to estimate FTP.

Easier to Pace & Execute: (this is now my go-to recommendation) Two all-out 5-minute efforts with an 8-minute break. Take the average power and multiply by 0.75 to find your threshold power. Retest every 4-6 weeks during training blocks.
Phase 1

Neuromuscular Development

Build the foundation with low-cadence torque work. This phase aims to develop neuromuscular pathways and muscular endurance—a base-building block before higher-intensity phases.

3 weeks · 1 session per week
Phase 1 · Base Building

Low Cadence / Torque Intervals

Neuromuscular pathways & muscular endurance

~90min
Total Session
55-60
RPM Cadence
1x/week
Maximum
7/10
RPE
Workout Prescription
5 × 4 min  or  3 × 10 min
Men Target
0.71 – 1.0 Nm torque
Women Target
0.6 – 0.9 Nm torque
Rest Between
8 minutes
Cool Down
30 minutes

Execution

  • Target Torque, Not Power

    These intervals are performed to a torque value, not power. Select torque display on your Garmin or Wahoo, or calculate after using the formula below.

  • Find a 6%+ Gradient

    Best performed on a climb with a minimum 6% gradient. This allows you to maintain the low cadence without fighting the bike.

  • 30 Minute Warm-Up

    Allow adequate warm-up time before the low-cadence efforts. Your muscles need to be prepared for the high-torque load.

Expect it to feel difficult — maintaining 55-60 RPM may feel awkward initially. You'll find it easier to hit the prescribed cadence as you progress through the training block.

Torque Calculation
Torque (Nm) = Power (W) ÷ (Cadence × 2 × π) × 60
Phase 2

Metabolic Development

Develop aerobic capacity with steady-state efforts just below threshold. This phase improves fat metabolism and lactate clearance.

4+ weeks · 2 sessions per week (3 for well-trained athletes)
Phase 2 · Metabolic

Sub-Threshold Metabolic Conditioning

Aerobic capacity & metabolic efficiency

80-100min
Total Session
80-85%
FTP Target
2x/week
Frequency
8/10
RPE
Workout Prescription
1 × 20 min @ 80-85% FTP
Warm-Up
30 minutes progressive
Cadence
80-100 RPM (self-selected)
Cool Down
30 minutes
Terrain
Flat or undulating

Execution

  • Consistent Power Output

    Aim for minimal variation in power throughout the interval. Smooth and steady is the goal—avoid surges and soft-pedaling. Choose routes without traffic lights or steep downhills.

  • Controlled Breathing

    You should be able to speak in short sentences. If you're gasping, back off the power slightly—this isn't a maximal effort, but it should feel like solid work (8/10 RPE).

  • Progressive Overload

    Weeks 1-4: Single interval, building duration: 20 min → 30 min → 40 min.
    After 4 weeks: Progress to 2 × 20 min or 2 × 30 min with 15 minutes recovery between intervals.

Indoor or outdoor — this session works well on a turbo trainer where you can precisely control power output, or outdoors on flat/undulating terrain without interruptions.

Phase 3

Threshold Development

Two complementary sessions to build sustainable power at and around FTP. This phase develops your ability to sustain race-pace efforts.

3 weeks · 2 sessions per week maximum (2-3 days between sessions)
Phase 3 · Session 1

Threshold Blocks

Sustained supra-threshold development

~2hr
Total Session
105-110%
FTP Target
Max 2x/week
Frequency
8.5/10
RPE
Workout Prescription
3 × 10 min OR 3 × 15 min @ 105-110% FTP
Rest Between
8-10 minutes easy spinning
Cadence
80-100 RPM
Warm-Up
30 minutes
Warm-Down
30 minutes
Terrain
Consistent uphill gradient (3-8%)
Recovery
2-3 days between sessions

Execution

  • Choose Your Duration

    Pick either 3×10 minutes OR 3×15 minutes and commit to that duration for all three intervals. Don't leave it ambiguous—decide before you start.

  • Find a Climb

    This session is designed for consistent uphill gradients between 3-8%. The sustained gradient helps maintain steady power output and proper pacing.

  • Even Effort Distribution

    All three intervals should feel equally hard. If the third feels much harder, you started the first two too aggressively. This is supra-threshold work—it should hurt, but sustainably.

Without a power meter? Target RPE 8.5/10 during intervals. This should feel like hard, sustained race effort—uncomfortable but controlled.

Phase 3 · Session 2

Over/Under Intervals

Threshold tolerance & lactate clearance

~90min
Total Session
95-110%
FTP Range
Max 2x/week
Frequency
9/10
RPE
Workout Prescription
3 × 10 min (2min @ 95% / 1min @ 110%)
Interval Pattern
Alternate 2min/1min throughout each 10min block
Rest Between Intervals
10 minutes
Under Power
95% FTP
Over Power
110% FTP
Cadence
85-95 RPM
Warm-Up
30 minutes
Terrain
Flat or consistent gradient

Execution

  • The Pattern

    Each 10-minute interval follows this repeating pattern: 2 minutes at 95% FTP ("under"), then 1 minute at 110% FTP ("over"). You'll complete this cycle 3+ times per interval.

  • Smooth Transitions

    Don't spike power on the "over" surges. Ramp up smoothly over 10-15 seconds. The goal is controlled surges, not explosive attacks.

  • The "Under" Is Not Rest

    95% FTP is still working hard—you're training your body to clear lactate while maintaining near-threshold power. The discomfort builds as the interval progresses.

Race-specific fitness: Over/unders simulate the demands of racing—surges on climbs, covering attacks, then settling back to tempo without fully recovering. This is exactly what happens in competitive cycling.

Phase 4

High Intensity / VO2max

Push into the red zone with efforts above threshold. This phase maximises your aerobic ceiling and race-winning power.

3 weeks · Maximum 2 sessions per week
Phase 4 · Session 1

VO2max Intervals

Maximal aerobic power

~2hr
Total Session
115-120%
FTP Target
Max 2x/week
Frequency
Max
Sustainable RPE
Workout Prescription
5 × 2 min OR 5 × 4 min @ 115-120% FTP
Rest (5×2 format)
2-3 minutes
Rest (5×4 format)
2.5-3.5 minutes
Warm-Up
40 minutes
Warm-Down
30 minutes
Terrain
Consistent uphill gradient
Frequency
Maximum 2 sessions per week

Execution

  • Maximum Sustainable Effort

    The target is the maximum power you can sustain for the entire interval length. If you can't complete all five intervals at the same power, you started too hard.

  • Find Your Pace

    The first interval is a calibration effort. Find a power you can repeat for all five intervals—it's better to be slightly conservative than blow up early.

  • Maximise Time in Zone

    The adaptation comes from time spent at VO2max, not peak power. Consistent, repeatable efforts trump one heroic interval.

Choose your format: 5×4min accumulates more time in zone but requires pacing discipline. 5×2min allows higher power but less total stress. Both are effective for VO2max development.

Phase 4 · Session 2

40/20 Microbursts

Repeatability & anaerobic capacity

~90min
Total Session
Max
Effort Target
Max 2x/week
Frequency
10/10
RPE
Workout Prescription
6 × (40s max / 20s recovery)
Starting Volume
6 reps (6 minutes total)
Progression
Build to 10 × 40/20 over 4 weeks
"On" Effort
Maximal sustainable effort
"Off" Effort
20s easy recovery spinning
Warm-Up
40 minutes
Warm-Down
40 minutes
Terrain
Uphill gradient 3-6%

Execution

  • Progressive Overload

    Start with 6 repetitions in week 1. Add 1 repetition per week until you reach 10 × 40/20 by week 4. This gradual progression allows adaptation while managing fatigue.

  • Maximal Efforts, Not Power Targets

    Each 40-second effort should be maximal—the hardest sustainable effort you can maintain for that duration. Don't focus on hitting a specific wattage; focus on genuine max effort.

  • Incomplete Recovery by Design

    20 seconds is not enough to fully recover. That's the point—you're training your body to perform repeatedly under accumulating fatigue, just like racing. If you find you can't complete the session, start with 40 seconds recovery and progressively lower to 20 seconds over multiple sessions.

  • Find a Climb

    The 3-6% gradient helps maintain consistent power output and prevents over-acceleration. Too steep and you'll struggle; too flat and power will fluctuate.

Race simulation: 40/20s mimic the repeated accelerations of criterium racing, covering attacks, and punchy climbs. The ability to go hard, recover incompletely, and go hard again is a race-winning skill.

Bonus Session

Rønnestad Intervals

My go-to emergency race preparation session.
If you get a surprise call-up to an event, this is a good way to prepare at short notice.
A research-backed protocol developed by Dr. Bent Rønnestad for elite cyclists. Exceptionally effective for VO2max development.

Rønnestad 30/15 Intervals

Elite-level VO2max training

~60min
Total Session
MAX
Effort Target
Max 2x/week
Frequency
10/10
RPE
Workout Prescription
3 sets × 13 reps (30s max / 15s recovery)
Set Duration
9 min 45 sec per set
Rest Between Sets
10 minutes
"On" Effort
30s maximal effort
"Off" Effort
15s easy recovery
Cadence
80-100 RPM
Warm-Up
30 minutes
Warm-Down
30 minutes

Session Structure

Visual representation of the 3 sets with 13 repetitions each

Warm-up 30min Set 1 9:45 Rest 10min Set 2 9:45 Rest 10min Set 3 9:45 Cool 30min
30s MAX effort
15s recovery
10min rest between sets

Execution

  • True Maximal Efforts

    Each 30-second interval should be a genuine maximal effort—the hardest sustainable power you can produce for that duration. This is not a percentage; it's all-out effort.

  • ERG Mode Recommended For Indoor Sessions

    The short intervals make this session ideal for a smart trainer in ERG mode. The trainer handles power transitions while you focus on pedalling through the efforts.

  • Incomplete Recovery Is Key

    The 15-second recovery is deliberately insufficient. You're training your body to produce maximal power repeatedly without full recovery—a critical race skill.

  • Research-Proven Results

    Studies show this protocol produces greater VO2max improvements than traditional long intervals, with subjects spending more total time at >90% VO2max.

Advanced session: This is for well trained athletes only. Please do not try this on a whim, or without a proper warm-up and experience riding at high intensities. Always train within your ability to maximise training benefits and avoid potential injury.

About the Author

Coach John Wakefield
Coach John Wakefield
S2S Coach & Director of Coaching at Red Bull - BORA - hansgrohe
In 2008, after developing a strong working relationship with Dr. Jeroen Swart, John was inspired to start coaching and invest in Science to Sport as one of the founders. After moving to Girona, Spain in 2019 and setting up the S2S Performance Lab in the centre of town, he now calls Andorra home. John is also Director of Coaching, Sports Science and Technical Development at Red Bull - BORA - hansgrohe. Prior to this he cut his teeth in World Tour cycling with a 4 year stint at UAE Team Emirates, working on that final TT that won Tadej Pogacar his first tour in 2020.
Coaching Background
John's racing and coaching career began in motocross where a young Matt Beers was one of his proteges. A bad leg break for Matt led to some MTB rehab, then a few bike races entered 'for fun', with Matt finishing on the top step of the podium, and the rest is history. Prior to Matt's accident, a broken leg for John at the motocross track had sent him down the same path - to road racing and MTB stage racing, where he began to take on cycling clients. To date he has worked with multiple Grant Tour and Cape Epic winners, World Champions and numerous national titleholders across all cycling disciplines.