Version 1.19 includes an improved and better organised statistics page.

The statistics page is quite simple to find on the iPhone. A few users on iPad sometimes miss it as it’s a bit less obvious, you need to press the stats icon pointed by the blue arrow below.

The New Fields Stats Page

The new stats page now have the fields pre-organised rather than trying to dynamically work out the ordering based on all the fields found on garmin connect data. This is both so that it works better with other services than garmin and due to the fact that the data include now a lot of new fields that confuses the old logic resulting in quite a messy page. Note that any fields not known by the app will still appear systematically at the very end of the list under the category Other.

One new feature is that you can now have a quick filter to see the summary stats for either the week or the month of the most recent activity. For that press the Sum Icon, which will then turn into a week or month icon as pointed by the arrow below.

Weekly or Monthly Summary

As before if you press the All button on the right it rotates through weekly, monthly or yearly summary. There is now also a quick filter for these pages. If you press the All button pointed by the arrow below you’ll enter to filtered page for the last 3m, 6m or year.

Note that if you want to get more detail on an activity you can now tap on the line for the period you are interested in and it will bring up the page with that full stats on the activities. Below you will see all the statistics for the week starting on the 23rd of march.

It achieves that with the search feature, the activity list will also contains only the relevant activities. You can from the activity clear the search to see the full list of activities again. When the stats are about the current search it then replace the activity type icon. Note that you can this way get stats on any subset of activity you can define with a search in the activity list screen.

ConnectStats let us apply basics statistics technics to analyse our fitness data. We use these techniques to answer questions about the activities. How well did I do on this run? Is my stamina improving? Did I push myself more today that last week?

Raw Data

Before doing any analyses, let’s review the raw data we have access to. ConnectStats relies on the collection of the data is done with a garmin device and a collection of sensors.

The raw data varies by activity type and device.
For outdoor activities, the raw data will be gps coordinates, a timestamp, speed and values from different sensors: Heart Rate beat per minutes, cadence (legs or pedal), Power delivered on the bike, and sometimes more advance running dynamics like Vertical Oscillation, ground contact time. For swimming the data collected will be the time for each length and the number of stroke.

Here is an example of what the raw data looks like

Depending on the activity or the device the raw data will be collected at fixed intervals or at different intervals trying to reduce the amount of data saved. If you move in a straight line for 5s at constant speed, it isn’t necessary to collect the points every seconds as they can easily be interpolated.

From this raw data, there are two main directions for the analysis we can do. The first is analysing a single activities and the second is analysing summary of each activities over time.

Focus on a single activity

The summary statistics are quite simple. Mostly we will want to look at the average of the different measure, maximum and minimum. Where it gets more interesting is to look at the series of data. As for most statistics analysis a first phase will be cleaning the data.

Data Cleaning

Let’s look at the graph of the data collected by the gps. You can see it is quite noisy, there is also large part of the data that is not really interesting to look at to. Some is gps noise, area with bad reception, pause due to stop lights,

To clean the data, we can first use assumption on expected constraints on the data. For example, define a minimum speed considered valid running speed, or a minimum valid heart rate to remove unreasonable spikes. Another technique used by connectstats is to filter points that have unrealistics acceleration.

The last smoothing technic we can apply is a moving average of a few points. Usually the app will use 5 points moving average for data, but it can be controlled in the sliding left settings window.

In the case below the graph start to be more readable now, especially with the 2 minutes moving average overlay, which shows the two short faster run intervals around 30min and 40min.