Frequently Asked Questions

The Norwegian Singles Method is a training methodology focused on sub-threshold training. It was adapted from the training of elite Norwegian runners for regular runners and emphasizes:

• A ratio of 75-80% easy running, 20-25% sub-threshold work
• Three sub-threshold sessions per week (short, medium, long intervals)
• No traditional VO2max workouts
• Consistent structure year-round
• Gradual volume progression

NSM doesn't include traditional VO2max work (very fast, short intervals) because:

• Sub-threshold training provides sufficient aerobic stimulus
• VO2max work creates more fatigue for less benefit
• Sub-threshold running allows for consistent year round running without the 'recovery' weeks needed when using VO2max workouts

Traditional training uses periodization (base, build, peak phases) and includes threshold and VO2max workouts. NSM:

• Uses the same structure every week, year-round
• Only includes sub-threshold intervals (no threshold or VO2max)
• Emphasizes higher volume with more easy running
• Progresses through volume increases, not intensity changes

The 75/25 ratio means 75% of your weekly running volume should be easy, and 25% should be sub-threshold work. This ratio:

• Allows high volume without excessive fatigue
• Provides sufficient quality stimulus for improvement
• Is sustainable long-term

SubThreshold tracks this as "compliance" - aim for 20-25% sub-threshold volume each week.

NSM works best with 7 running days per week but can be adapted for running 5 or 6 days:

• 7 days: Optimal for NSM (3 quality, 3 easy, 1 long run)
• 6 days: Good (3 quality, 2 easy, 1 long run)
• 5 days: Minimum (3 quality, 1 easy, 1 long run)

Running 7 days is possible in NSM because you accumulate less fatigue than other training methods. If this still sounds like too much, then you can start with fewer days and gradually progress to 7 days. Fewer than 5 days would not likely provide the same benefits and a more traditional training plan might be the better option in this case

Choose weekly volume based on your current running:

• Low: 4.5-6 hours/week
• Medium: 6-7.5 hours/week
• High: 7.5-9 hours/week

Start conservatively - you can always increase volume later.

It is recommended to increase volume when your training load (Fitness in Intervals.icu) has stabilised. This indicates your body has adapted to the current workload and is ready for more. If you're using Intervals.icu, watch for your Fitness score to plateau after consistent training. Once it levels off, you're ready to progress to the next volume tier.

If you're not tracking Fitness in Intervals.icu, signs you've adapted include:

• Workouts feel more comfortable than when you started the volume tier
• If you measure your Heart Rate, your HR is consistently lower for the same pace or power than when you started the volume tier
• You're recovering well between sessions
• Easy runs feel genuinely easy

At block review, SubThreshold prompts you to consider your next block. If your load has stabilised and you're handling training well, increase by one tier (approximately 30 minutes per week). If you're still adapting or feeling fatigued, stay at your current volume for another block. When in doubt, consolidate. Consistent training at a sustainable load beats pushing volume too quickly.

Go to the VDOT Calculator and enter a recent race result:

1. Enter your 5k race time
2. SubThreshold calculates your VDOT and training paces

Use your most recent race for accuracy. If you haven't raced recently, run a 5k time trial.

Run a time trial to establish your VDOT:

• 5K time trial: Most accurate for VDOT calculation

Warm up properly, run at maximum sustainable effort, and use that time in the calculator.

Pace-based (VDOT):

• Simple and proven
• Works on any terrain
• Affected by wind, hills, fatigue

Power-based (Critical Power):

• Consistent across conditions
• Great for hilly terrain
• Requires Stryd power meter
• More complex to understand

Start with pace-based unless you already have a Stryd device and understand power training.

If using power-based training:

1. Get a Stryd power meter
2. Run their Critical Power test protocol
3. Enter your CP in SubThreshold Settings
4. Use power ranges in your SubThreshold workouts

You don't. NSM is not like traditional plans that are focused on specific race distances. With NSM:

• You train year-round using the same structure and gradually increase volume
• After some time following this method, you will be able to run races up to and including Half Marathon distance at any time without having trained specifically for that event

NSM can prepare you for races up to half marathon without modification. Marathons, however, require specific adaptations that go beyond the standard NSM structure.

SubThreshold does not currently generate marathon-specific plans. If you're training for a marathon, you can build a customised plan using the workout library and custom workouts.

The 'Norwegian Singles Method' book provides detailed guidance on the adaptations needed for marathon preparation.

The workout library contains NSM workouts in both time-based and distance-based formats:

• Time-based workouts (e.g., 5×4min, 3×10min)
• Distance-based workouts (e.g., 10×1K, 4×2K)

Drag workouts from the library to your calendar. Paces or power targets are automatically calculated from your VDOT or Critical Power.

Yes! You can create custom workouts with your own interval structure:

• Choose number of intervals and duration
• Set effort level (15K, HM, or 30K)
• Add warmup and cooldown

Custom workouts are added to your library and from there can be added to your calendar.

The plan generator creates a personalised NSM training block based on your inputs:

• Fitness Level - Enter your recent 5K time (for pace-based training) or Critical Power (for power-based training). This determines your workout target paces or power zones.
• Days per week - Choose 5, 6, or 7 training days. The generator allocates three quality sessions and fills remaining days with easy runs, including one longer easy run.
• Weekly Volume - Select your target hours per week in 30-minute increments (4.5h to 9h).
• Block Length - Choose 4, 6, or 8 weeks of workouts to be generated. Continuous training happens by generating new blocks after each block is completed
• Race dates (optional) - Add 10K or Half Marathon race dates to include taper and reverse taper weeks.

The generator produces a complete block with all workouts scheduled in the correct order (long intervals, medium intervals, short intervals) with appropriate warmup, cooldown, and rest periods. Every week includes all three interval types to maintain balanced training stimulus.

Once generated, you can load the plan to your calendar, make manual adjustments if needed, and push workouts to Intervals.icu for syncing to your watch.

Intervals.icu is a free training analysis platform that syncs with most GPS watches and fitness apps (Garmin, Wahoo, Polar, Strava, etc.).

SubThreshold connects to Intervals.icu to push your workouts directly to your watch. When you generate or manually build a plan, connecting to Intervals.icu means your workouts appear on your device with target paces or power - no manual entry required.

Connecting is optional. Without it, you can still view and follow your plan in SubThreshold, but you'll need to remember your workout details or refer to the app during your session.

If you have an Intervals.icu account:

1. Go to Settings → Intervals.icu Integration
2. Connect your account
3. From your calendar, click "Push to Intervals.icu" to push workouts for that week or push individual workouts by clicking them and viewing the details

Workouts appear in your Intervals.icu calendar for easy tracking.

No, SubThreshold only generates time-based plans. Time-based workouts ensure consistent training load across all ability levels - a 10×3min session takes the same time whether you're running 4:00/km or 5:30/km pace.

If you prefer distance-based workouts, the workout library contains distance-based options and you can create custom distance workouts to add to your calendar manually.

You may notice that the upper pace range for short intervals (15K effort) can be slightly faster than the displayed threshold pace. This isn't a bug - it reflects how the different calculations work.

The threshold pace shown in SubThreshold is calculated using the Jack Daniels VDOT formula, which is a well-established method for estimating lactate threshold pace from race times.

However, the actual training zone paces are calculated using the formulas specified in the Norwegian Singles Method book, which are based on race pace multipliers rather than threshold percentages. These formulas account for the fact that shorter intervals can be run slightly faster while remaining in the same sub-threshold physiological state (2.5-3.5 mmol lactate).

In practice, running 3-minute intervals a few seconds per kilometre faster than your threshold pace still keeps you in the sub-threshold zone because the effort is brief and you recover between repetitions. The book's paces are designed to maximise training stimulus while keeping you below the lactate accumulation point.

The name SubThreshold reflects the methodology's core principle: all quality work targets the sub-threshold zone to build aerobic capacity without the fatigue cost of true threshold or VO2max training.

NSM uses three sub-threshold zones for different interval durations:

• 15K Pace/Power (Short): For 3-4 minute intervals (e.g., 10x3min)
• Half Marathon Pace/Power (Medium): For 6-8 minute intervals (e.g., 5x6min)
• 30K Pace/Power (Long): For 10-12 minute intervals (e.g., 3x10min)

All three maintain sub-threshold intensity despite different durations.

Only update your VDOT or CP when you have run a new race or time trial. In NSM, you get faster by doing more work at the same intensity, not by running your workouts faster.

Running at paces beyond your current fitness defeats the purpose of sub-threshold training. Aim to race or time trial every 4-8 weeks to validate your training zones.

A 5K race or time trial is ideal - it's long enough to reflect aerobic fitness but short enough to recover from quickly. If your result improves, update your VDOT or CP in SubThreshold. You should also update these values in Intervals.icu so it can accurately measure your training load. If not, continue training at your current paces.

SubThreshold doesn't schedule races or time trials automatically, but you can specify 10K and Half Marathon race dates when generating your plan. When you add a race date, SubThreshold allocates a taper week before the race and a reverse taper week after to help you arrive fresh and recover properly.

For 5K races or time trials, you should schedule these yourself as they require no tapering. Simply skip or delete the scheduled workout for that day in SubThreshold - your compliance tracking will adjust accordingly.

Regular racing or time trials every 4-8 weeks are recommended to validate your training zones and update your VDOT or Critical Power when you improve.

This is configurable in SubThrshold. NSM rest periods:

• Short intervals (3-4 min): 60 seconds
• Medium intervals (6-8 min): 60 or 90 seconds
• Long intervals (10-12 min): 90 or 120 seconds

Rest can be standing, walking, or light jogging - your choice.

For generated plans, SubThreshold calculates your long run duration based on your number of running days and weekly volume

If you have scheduled a Half Marathon in SubThreshold, you have the option to extend the long run to your chosen duration. This is done at plan generation and block review