Equipment Usage and Costs

:: training data analysis

I paid $600 for my Garmin FR920 GPS watch, and since I got it, I bought six pairs of running shoes totaling $1124 and went to the swimming pool 153 times: at approximately $5 for a swim session, this is $765 spend on swimming. While the FR920 cost more than a single pair of running shoes or a single swimming session, it actually comes out as cheaper to own than the previous two.

The ActivityLog2 application can track equipment used in each training session, such as running shoes, GPS watch or bike. I use this feature mostly to track service reminders: when to replace running shoes or the chain on my bikes, but once in a while I export the usage data as a CSV file, load it up in Google Sheets and calculate cost/use values for the equipment I use. The cost/use metric is simply the cost of the equipment divided by the number of uses. I think this is a more relevant metric than simply the cost, since a piece of equipment that I use a lot is more worth while than a cheaper one that I don’t use much.

Using the cost/use metric, my Garmin FR920 is the least expensive piece of equipment I own: I purchased one in November 2014 for $600 and I used it 772 times on running, swimming, biking and hiking sessions. The cost for each session comes out to be just $0.78. I plan to use my FR920 for at least another 6 months and, in that time, the cost/use will come down but at the same time, I will get another pair of running shoes and spend a lot more on swimming. The table below summarizes the cost/use for the FR920 versus running shoes or swimming sessions :

Equipment Cost / Session
Garmin FR920 $0.78
Running Shoes $2.66
Swimming Session $5.00

I buy a new pair of running shoes after I use the old pair for about 750 - 800 km . Some time ago, I noticed that my knees started hurting once I ran more than 800 km on a pair of shoes, so now I try to replace them at 750 km. Looking at 11 pair of shoes I went through in the past 7 years, I pay on average $173 for a pair and use it about 65 times: the average cost for a running session is about $2.66.

The bikes are probably the most expensive item even using the cost/use metric: my mid-range road bike (the Azuri Imperia), which I had for 7 years, still cost me $5.99. My TT bike (a Specialized Shiv) still cost $63.49, although I only had it for less than 2 years and used it only 63 times. Also, bikes are the only piece of equipment that I service regularly, so there is an additional cost of owning them, this cost is not included in these calculations. Power meters are another piece of equipment with a high cost/use, although less so than the bikes, probably because they cost less.

The full usage and costs are listed below. Azuri Imperia and Specialized Shiv are my bikes (road and TT respectively), the Vector and Vector 2 are power meters, one for each bike. The Brooks set of “equipment” are all running shoes. Tacx Vortex is a bike trainer. The rest of the equipment names should be self explanatory. The “Retired?” column shows equipment which I no longer use, for these the cost / use and cost / hour will remain fixed. For each equipment that is not retired, the cost / use and cost / hour will come down as the use count and hours used increase while the cost stays the same.

Name Retired? Use Count Hours Used Cost (AUD) Cost/Use Cost/Hour
Azuri Imperia 375 558 $2,245.00 $5.99 $4.02
Specialized Shiv 63 99 $4,000.00 $63.49 $40.33
Bike speed cadence yes 287 449 $100.00 $0.35 $0.22
FR–310 Footpod yes 285 309 $100.00 $0.35 $0.32
FR–310 yes 651 852 $500.00 $0.77 $0.59
FR–920 772 811 $600.00 $0.78 $0.74
Garmin Swim yes 167 155 $180.00 $1.08 $1.16
Vector power meter 151 186 $1,200.00 $7.95 $6.45
Vector 2 power meter 63 99 $1,800.00 $28.57 $18.15
Tacx Vortex trainer 27 21 $550.00 $20.37 $26.52
Brooks running shoes yes 69 72 $169.00 $2.45 $2.33
Brooks running shoes yes 66 69 $170.00 $2.58 $2.46
Brooks running shoes yes 73 75 $170.00 $2.33 $2.28
Brooks running shoes yes 52 73 $170.00 $3.27 $2.33
Brooks running shoes yes 76 81 $100.00 $1.32 $1.24
Brooks running shoes yes 75 69 $170.00 $2.27 $2.45
Brooks running shoes yes 76 68 $179.00 $2.36 $2.65
Brooks running shoes yes 72 66 $179.00 $2.49 $2.72
Brooks running shoes yes 73 69 $189.00 $2.59 $2.72
Brooks running shoes yes 51 74 $187.00 $3.67 $2.53
Brooks running shoes 33 29 $220.00 $6.67 $7.70