Peak Week Calculator

Peak week is the single highest-volume training week in a running program — the culminating block of hard work that comes two to three weeks before race day. It represents the summit of your training cycle: the point at which accumulated fitness, mileage, and quality workouts converge before the body begins its taper. Done correctly, peak week sends a powerful stimulus to your aerobic system, muscle fibers, and connective tissues, priming you for peak-race performance.

Distance runners across every level — from recreational 5K athletes to competitive marathon runners — rely on a structured peak week to bridge the gap between training and racing. The concept is grounded in the principle of supercompensation: stress the body to its adaptive limit, then give it time to recover and rebuild at a higher performance ceiling. The taper that follows peak week allows glycogen stores to refill, muscle damage to repair, and neuromuscular sharpness to peak precisely on race day.

Peak week is not simply "the week with the most miles." It is a carefully proportioned blend of long-run distance, quality (speed and tempo) work, and easy aerobic running. Overloading any single component — cramming in extra long runs or piling on track intervals — can lead to fatigue, injury, or under-recovery heading into the taper. This peak week calculator takes your total weekly mileage, race type, and available training days and distributes volume across long, quality, and easy runs in ratios validated by elite coaching frameworks.

The race type matters enormously. A 5K-focused peak week demands a higher proportion of speed work and a shorter long run, while a marathon peak week shifts emphasis toward longer aerobic runs and marathon-pace efforts. The calculator adjusts these percentages automatically so every recommendation is tailored to your specific goal race.

The peak week calculator distributes your total weekly mileage into three training zones using race-specific percentages. Each race type has its own configuration for long-run percentage, quality-work percentage, and a hard cap on long-run distance to prevent overreaching.

Once the three volume buckets — long run, quality work, and easy runs — are calculated, the calculator maps them onto a seven-day schedule. The template follows a time-tested weekly rhythm used by coaches at every level:

• Monday: Rest or cross-training (0 km). Recovery after the weekend's accumulated fatigue.
• Tuesday: Quality session #1 — 50% of total quality-work volume. Typically the week's first track or tempo session.
• Wednesday: Easy run — 25% of easy-run volume. Active recovery between hard efforts.
• Thursday: Quality session #2 — the remaining 50% of quality-work volume. A second stimulus before the weekend.
• Friday: Easy run — another 25% of easy-run volume. Pre-long-run freshening.
• Saturday: Long run — the full calculated long-run distance.
• Sunday: Easy run — the remaining 50% of easy-run volume. Aerobic flush after the long effort.

When you select fewer than seven running days, Friday's run is removed first (rest day added), then Monday's cross-training slot is converted to full rest. This preserves the hard-easy-hard structure while accommodating real-life scheduling constraints. Athletes training just four to five days per week will find the easy volume naturally consolidates into fewer, slightly longer easy runs.

The total "planned" mileage displayed by the calculator is the sum of all day-level distances after rounding. Due to integer rounding at each step, this figure may differ by one or two kilometres from your input weekly mileage — a normal artefact of the formula and not a cause for concern.

Timing is everything. For most race distances, peak week should fall two to three weeks before race day. A marathon taper typically spans three weeks, placing peak week at the start of that block. Half marathon tapers commonly run two to three weeks. For 10K and 5K races, a two-week taper is usually sufficient, so peak week sits two weeks out from race day.

After peak week, weekly mileage drops sharply. A common approach is to reduce total volume by 20–30% in the first taper week, then by another 20–30% in the second week, arriving at race week with only 40–50% of peak mileage remaining. Quality workouts are shortened but not eliminated — short, sharp sessions maintain neuromuscular sharpness without adding accumulated fatigue. The long run is significantly reduced: there is no fitness to be gained from a 30 km run ten days before a marathon.

Common taper mistakes include doing too much (adding "just one more workout"), doing too little (complete rest that leads to flat legs), and changing diet or equipment during this sensitive window. Trust the process: the fitness is already built. Peak week is the last deposit; the taper is the withdrawal.

Athletes who train at high volume (90 km+ per week) may benefit from an extended three-week taper that reduces mileage more gradually. Runners under 60 km per week generally recover quickly and can follow a standard two-week taper without losing fitness. Use the peak week calculator alongside a tapering calculator to map the full pre-race build-down.

The type of quality work in peak week should mirror the physiological demands of your target race. Running faster than race pace in short intervals trains your VO2 max and running economy; running at or near race pace for sustained efforts builds the specific endurance your race requires.

5K training: 800-metre repeats at 5K goal pace are the gold standard, developing the aerobic power needed to sustain a fast 5K. Kilometre intervals and tempo runs at 10K effort also feature prominently, building a wide aerobic foundation beneath the speed work.

10K training: One-kilometre repeats at 5K pace sharpen speed, while 5–6 km tempo runs at comfortably hard effort build lactate threshold. Three-kilometre intervals bridge the gap between raw speed and sustained race pace.

Half marathon training: Tempo runs of 8–10 km are the centrepiece, training the body to hold half-marathon effort for an extended period. Cruise intervals (shorter tempo efforts with brief recoveries) and half-marathon-pace miles within the long run add specificity.

Marathon training: The long run itself becomes a quality workout: marathon-pace long runs (running the final 10–16 km at goal marathon pace) and progressive long runs (starting easy and finishing at or faster than marathon pace) are the most race-specific peak-week sessions available. A traditional tempo run still has value for maintaining efficiency, but marathon-pace work is the priority.

Regardless of race distance, ensure at least one full easy day between quality sessions. In peak week, accumulated fatigue is already high; adding poorly spaced hard efforts is one of the most common causes of pre-race injury and burnout.

Peak week walks a narrow line between maximum productive stress and overtraining. Warning signs that peak week has crossed into overreaching include persistent muscle soreness that does not resolve with sleep, elevated resting heart rate, disrupted sleep, irritability, loss of motivation, and declining pace at the same perceived effort. If two or more of these symptoms appear together, reducing peak-week volume by 10–15% is a sensible precaution — arriving at the start line slightly undertrained is far better than arriving injured or fatigued.

Nutrition plays a critical role during peak week. Carbohydrate intake should match the elevated training load: athletes running 80–100 km in a week may require 7–10 grams of carbohydrate per kilogram of body weight per day to keep glycogen topped up. Protein supports muscle repair (1.6–2.0 g/kg/day is the commonly cited range for endurance athletes), and hydration becomes especially important as sweat losses accumulate across back-to-back training days.

Sleep is the single most important recovery tool during peak week. Research consistently shows that sleep restriction impairs endurance performance, increases injury risk, and slows recovery between sessions. Aim for seven to nine hours per night throughout the week, and do not sacrifice sleep to fit in an additional workout.

Use this peak week calculator to set a realistic total volume. If the number generated feels significantly higher than what you have been training at, consider dialling back to a level that represents a five to ten percent increase over your most recent hard week — a peak week should be achievable, not a dramatic jump that shocks the system.