Panel 1: We find ourselves watching Elly and Connie react to the artificial crisis Lynn's body issues has created by having them go jogging. Connie explains why by telling Elly that every time she feels "old", she should exercise because at their "age", it's essential. As any major dude could tell you, this is gonna hurt because you have to pace yourself when undertaking any sort of exercise regime and can't just get up and jog if you spend most of your time sitting on your ass whining about being old. You could end up surrounded by pop art captions that say "Puff" and "Wheeze" like them if you did that.
Panel 2: She reminds us of Lynn's bad habit of working back from the end gag by stating that they must regard exercise with a sense of purpose and a sense of determination. She also reminds us that Lynn combines having "old" days with "fat" days by having something "Flap! Flap! Flap!" in the breeze as they go by.
Panel 3: We get a great big whiff of Elly's body issues as we see their country-wide asses jiggle and thump as they puff and wheeze and flap.
Panel 4: This causes Elly to thought-bubble "A sense of humor" because she thinks that she and Connie are kidding themselves.
Summary: I should think that this should occasion the first Lynnsight that has our hero confuse the pain involved in going from a sedentary lifestyle to activity with a normal consequence of old age. Meanwhile, I still remember a PSA from the 1970s that compares the average Canadian suburbanite in her late thirties unfavorably to a 63-year old Swede.