John is so used to feeling a little like Superman; lifting huge objects with his fingertips or somersaulting with a simple tuck and turn, that getting back down to Earth when his rotation finishes, really screws with him. Right after he lands, his biggest problem is that suddenly he can feel the weight of his lips and tongue again he has to change how he is talking; having not realized he was so used to having a weightless tongue. Everyone has to get used to slurry John speak for the first few hours. Gordon calls it ‘martian-babble’ and insists it’s the language he’s been using to chat with friendly aliens up there and John squints grumpily at him (his eyeball pressure has yet to return to normal and he’s seeing everything blurry, like an out of focus camera - he’s got little glasses to correct it but refuses to wear them because he thinks he looks like a dork) and tries to slap him upside the head for it. He misses.
His bone density has lessened and his muscle mass has shrunk, and so, as soon as he’s dragged his corpse out of bed and reached blearily for a coffee he’s in the gym, or running along the beach with Scott, or in the pool with Gordon, trying to persuade his body to cooperate and hoping he’ll stop breathing like an asthmatic sometime soon. Carido is hell, but necessary. The calluses on his feet have all but disappeared, as in space there’s no friction and pressure from walking to keep them built up. His soles are more than a little sore as they pound over the sand, trying to keep pace with Scott.
He has balance issues for a good couple of weeks, wobbling around like he’s had several too many to drink, and he has more than one argument with gravity that ends with him on the losing side; face planting the ground. The wobbling about also makes him nauseous, and sometimes it’s all he can do to stand, eyes squeezed shut, focusing on keeping the contents of his stomach firmly where it belongs. His brothers, Alan in particular, shoot him sympathetic smiles, they’ve all done rotations after all, but they’re aware that John always feels the post-space adjustment a lot harder than they ever do; he spends more time up there than the rest of them combined.
John also keeps finding things he’d let go of, expecting them to float in zero gravity, smashed on the floor. He tries to push objects across the room to other people, instead of handing them over, and he actually looks surprised when they fall and break. Scott is always super careful to (irritatingly) remind him of this whenever he passes him hot drinks. He doesn’t want a repeat of that one time (in which they had both attained shiny pink burn marks in their laps when John had reached out to leave his coca in the air). He drops other things too, pens, books, food, and the brothers have learned to keep an eye on whatever he’s holding encase they need to dive in and catch it. There was once an incident with a very young child in which John had forgotten that if he let go of the complaining, wriggling boy, that he wouldn’t just float. They’ve kept him firmly away from small children ever since and Gordon had daubed ‘keep this man away from babies’ across the back of his favorite old NASA t-shirt with Virgil’s impastos and John had rained down wobbly astronaut hell on him for that one.
He has to wear a g-suit under his clothes to make sure his blood pressure is getting to his head and his first few showers take place sitting down. John has trouble keeping with Earth time and often can be found sleeping in the middle of the day or making breakfast at midnight. He sleeps incredibly lightly when he does, a result of always being ready to hear and respond to IR calls, and there’s a real problem with his family accidentally waking him up when he’s trying to get some rest. They’re apologetic when they do, and they try their hardest to tiptoe around him and his screwy sleep patterns while he re-adjusts.
The return to Earth food after eating what Alan fondly calls ‘cardboard space food‘ (nutritionally sound cardboard space food, but cardboard space food all the same) feels like heaven, and he has a good excuse not to go near Grandma’s cooking because he ‘can’t eat anything that heavy yet’. That doesn't stop him from pillaging the freezer for Virgil’s ice cream stash though. Or from eating all the valentines chocolate Alan gotten before the poor boy had a chance. Or that time the whole pizza Scott had ordered had mysteriously disappeared. John also gets bad dehydration headaches if he didn’t take enough salt tablets and drink plenty of water before re-entry, and he finds the only cure for those is curling up in the peaceful dark of his room with all his lights off, huddled in his duvet with the comfort of the faint, light strands of Virgil on the piano, that echo from somewhere in the house.
He’s glad to be home though, he thinks, as he shields his eyes from the sunlight and watches his brothers try and push each other in the pool. Alan has the net they use for scooping out leaves as is using it like a cattle prod to force Scott towards the water. He loves space and he loves his stars and he loves doing his bit for International Rescue.
But sometimes he just misses his brothers.