Track shoe miles all winter.

Why winter makes the log worth keeping

In summer most people run in one or two pairs. Winter changes that. Short days push sessions onto the treadmill, snow and slush call for a pair you do not mind getting wet, and a race-prep block adds hard sessions that you might want in a firmer pair. Before long four pairs are in rotation and nobody can say which one has done what.

A shoe log answers three plain questions. How far has each pair gone? How much has it done lately? What did it cost for the distance it has covered? Once you can answer those you can decide when to look closely at a pair, which pair gets the long run this week, and whether a November sale is worth acting on. This guide builds a log from scratch, runs a two-pair example through December and into January, and shows every sum.

• What to record
• Setting up the pairs
• Logging runs in km or miles
• A reminder you choose
• Worked log: two pairs
• Cost per kilometre
• Comparing a replacement
• The January reset

What to record

Keep the list short so that you actually do it. For each pair you need a name, the date you bought it, the distance it had already done when you started the log, what you paid and, if you want a reminder, an interval. For each run you need a date, the pair, the distance and the surface. That is all of it.

Everything else comes out of those fields. Totals are the opening distance plus the runs. Recent usage is the runs inside a date window. A reminder is the interval added to the distance at your last check. Cost per kilometre is the price divided by the total. Because nothing is typed twice, a correction in one place fixes every figure that depends on it.

Setting up the pairs

Name them plainly

Pair A, Pair B, "Road", "Trail" or "Treadmill" are all fine. A name only has to be unique and quick to pick from a list at the end of a run. Skip long descriptions, since they do not help when you are logging on a phone with cold fingers.

Set the opening distance

If a pair has history, enter it as the opening distance rather than inventing runs to match. In the example below, Pair B was bought in June and already carried 320 km on 1 December. Pair A was bought in September and was logged from zero. The opening distance counts towards the total and the cost per kilometre, but not towards recent weekly usage, because it was not run this month.

Put in the price

The price is optional but it makes the cost figures possible. Use what you actually paid. If you want to compare against a sale later, the regular price of a replacement goes in a separate box so the two never get mixed up.

Logging runs in km or miles

Log each run the way your watch reports it, even if you switch between kilometres and miles. A mile is exactly 1.609344 km, and the tracker stores every distance as a whole number of micrometres: 1,000,000,000 per kilometre and 1,609,344,000 per mile. Sums of whole numbers stay exact, so mixing units never drifts.

The trap is rounding each run before adding. Take forty 0.25-mile strides. Exactly, that is 10 miles, or 16.09 km. Convert each stride to kilometres and round to two decimals, 0.40 km, and forty of them add up to 16.00 km: nearly 100 metres missing from one pair after a few weeks of drills. The fix is to add first and round once, at the moment of display, which is what the ledger does.

Add the surface as you go. Road, trail, track, treadmill and snow or ice are enough. It costs one tap and later tells you what each pair has been through.

A reminder you choose

An inspection interval is a distance after which the log reminds you to look at the pair. You pick it. Some people pick 100 km for a pair that gets abused on trails, others 300 for an easy road pair; the example uses 150 km for both. Nothing about the number is official, and it does not say when a pair stops being useful. Its job is to make sure you pick the shoes up and look at them.

The reminder counts from your last logged wear check, measured as distance on that pair, or from the opening distance if you have not logged one yet. Log a check and the next reminder moves one interval further on. It shows as "on track", "soon" when you are within a tenth of the interval, and "due" when you have passed it.

When the reminder comes, run through the same short list each time: the outsole where the tread has worn smooth, the midsole for creases and dents that stay, the upper and heel for tears or loose stitching, the laces and eyelets, the insole, and how the pair feels on a short jog next to another pair. Write down the date and the distance. Over a season those notes tell you more than any single number.

Worked log: two pairs from December into January

Here is a real-sized month. Pair A cost $130.00, was bought on 12 September 2026 and starts at zero. Pair B cost $95.00, was bought on 20 June 2026 and started the log with 320 km already on it. Both have a 150 km reminder. The log runs from 1 December 2026 to 4 January 2027, and the ledger date is 5 January 2027.

Totals on 5 January

Pair A: 8 + 12 + 14 + 10 + 16 + 10 = 70.0 km, with no opening distance. Pair B: 6.5 + 5 + 7.5 + 6 + 8 + 7 = 40 km of logged runs, plus the 320 km opening distance, which gives 360.0 km.

Recent usage

"Last 7 days" counts the ledger date and the six days before it, so on 5 January the window is 30 December to 5 January. Pair A has one run in it, the 10 km on 2 January. Pair B has one as well, the 7 km on 4 January, because its 8 km run on 29 December falls one day outside. The 4-week average uses the last 28 days, 9 December to 5 January: Pair A covered 14 + 10 + 16 + 10 = 50.0 km, so 12.5 km a week; Pair B covered 7.5 + 6 + 8 + 7 = 28.5 km, so 7.125 km a week, which shows as 7.1.

Notice the week of 28 December. It starts in 2026 and ends in 2027, and the ledger keeps it in one bar because weeks run Monday to Sunday. The year table does the opposite and splits by the date on each run, so 2 January lands in 2027.

Cost per kilometre, line by line

The formula is the price divided by the total distance on the pair, opening distance included, because the price paid covers every kilometre the pair has done, not only the ones you logged. For Pair A that is $130.00 ÷ 70.0 km, which is $1.86 per km. For Pair B it is $95.00 ÷ 360.0 km, or $0.26 per km.

Pair A looks seven times more expensive per kilometre, and that is the wrong conclusion to draw. It is early in its life, and a fixed price spread over 70 km is always going to look steep. Cost per kilometre only falls as distance builds up, so compare pairs at a similar distance, or compare what they are projected to cost at the end of a plan, which is the next step.

If a pair has no distance yet, or no price, the ledger leaves the figure blank. Dividing by zero would only print nonsense, and a dash is more honest.

Comparing a replacement before the November sales

A comparison is only useful if the assumptions are visible, so here they are. The plan is 12 weeks, roughly November to the end of January. Each pair is assumed to keep running at its 4-week average. A replacement would take over the distance the old pair would have covered. The replacement for Pair A has a regular price of $150.00 and the sale takes 20% off.

Read the table from the top. Left alone, Pair A finishes the plan at $0.59 per km, because 150 more kilometres dilute the same $130.00. A replacement at the sale price costs $0.80 per km over the same 150 km, against $1.00 at the regular price: the sale saves $30.00, or $0.20 per km. Counting both pairs together, the money spent on Pair A and its replacement works out at $1.14 per km over 220.0 km.

The figures do not tell you whether to buy. They tell you what the purchase costs per kilometre if your assumptions hold, and how sensitive the answer is. Change the plan length, double the weekly distance or cut the discount to 10% and the numbers move at once. For Pair B the same sums give $0.21 per km by the end of the plan, so there is no cost argument for replacing it; if you replace it, it would be because of what you see in the wear check.

The January reset

The turn of the year is a good moment to clear the decks, and the log makes it a five-minute job rather than a guess.

1. Export 2026. Download the ledger CSV and print the rotation ledger. You now have the year on file, with the 2026 and 2027 columns separated by run date.
2. Review each pair. Is it still in the rotation? Is the interval still the prompt you want? Log a wear check for any pair you inspected.
3. Reset the assumptions. Choose the plan length for the next months, change the sale discount to whatever applies, and overwrite the assumed distance where your training is about to change.
4. Keep the opening distance honest. If you start a clean ledger for 2027, enter each pair's total as its opening distance, and leave the cost as the price you paid.

If you are following a block of training over the same months, the winter training plan gives you twelve weeks of runs to log, and the race-day split planner turns the target time at the end of it into splits for each station.

Slips to avoid

• Logging the run to the wrong pair. Correct it from the run log by changing the pair on that run. Both totals update, and so does the reminder.
• Skipping the opening distance. A pair with 300 km on it looks unworn and the cost per kilometre is wildly high.
• Rounding as you go. Enter what the watch says and let the ledger do the adding.
• Treating the interval as a rule. It is a reminder to look. What you see on the pair matters more than the number.
• Comparing at different distances. A pair at 70 km and a pair at 360 km will never have the same cost per kilometre, so compare at the end of a plan, with the assumptions written down.