Compare a distance across running, cycling and swimming
A marathon, a 180 km ride and a 3.8 km swim are the three legs of an Ironman, and each is the same size of day. Put in a distance and see it in the other two sports.
The same size of day
Ride
43 km
Swim
900 m
10 km of running is a Path on the MONS scale · 41. Challenges of the same size: Ride 10 mile, Ride 20 km, Run 5 km, Swim 500 m, Ride 30 km, Run Forager's day.
What the same size means
MONS sizes every challenge on one scale, set so that the three legs of an Ironman come out equal. It is not time, and it is not calories: a 3.8 km swim takes far less time than a 180 km ride, and burns far less. It measures how hard the day is on your body.
So use it to compare, not to plan. A swimmer who can do 4 km has a big engine, but the legs for a marathon are built by running.
The app reads the training you have already done, in every sport, and points you at the challenge that fits.