Last year I was pulling a gol-darned trailer for all my stuff: gym bag, work clothes, work food, and my emergency kit was basically my entire bike-specific tool box.

This year, I've trimmed it down to where I just look like I'm going off touring: two rear panniers to contain my much trimmed-down gym bag (swimming gear and shave/shower/grooming stuff only), I am leaving some of my work clothes at work; still taking the same food with me (I eat a lot of fresh fruit and veg so an 8 or 12 hour day's worth of food tends to be bulky), and a minimal bike emergency tool kit. I'm also a bit addicted to chains for locking up, so there's some bulk and mass there.

Still, moving down from 4 wheels to 2 has increased my avg mph and shaved a bit of time off, and the panniers are a lot better to drag into a headwind than the trailer.

Maybe some day I will get down to where my commuter bike looks about like a sensible person's weekend bike camping rig.

Dunno how you people do it. Some days I commute to the gym and work with nothing but a seatpost bag. Can't stand a bunch of bulk.

Then again I work somewhere where I can make myself meals, so that helps.

Can you leave a lock/chain at both pool and work? And leave the pool locker lock attached to the lock/chain?
I've packed a microfiber camping towel when I was commuting. They dry quickly and pack small, about regular bath size towel. A swim chamois can get you from dripping wet to damp.

I wonder if fresh vegs could ride in a 2nd water bottle topped off with ice water. They would need to be cut up. Carrots, celery, cauli, broc that will be OK with a wet bumpy ride.

I'm sympathetic toward the OP's desire to swim and baggage needed.
I carry fins, pull-buoy, kickboard, goggles, hand-paddles as well as shower sandals, swim cap, swimsuit, towel, minimal toiletries.
Years ago I picked up a very nasty foot infection once from wet deck or shower stalls, I no longer go barefoot. The plastic pool decking is very uncomfortable to walk on barefoot anyhow.
I use a mesh laundry bag for the wet stuff and swim backpack for the dry stuff.
I would be hard-pressed to carry all that on a bicycle commute to work.

Is there a question here? Sounds like you just like to carry everything you might need, and it doesn't seem to be stopping you.

Sometimes you just do what you have to do. When I winter commute, I carry a full change of clothes including my winter jacket, shoes, gloves, hat. My winter jacket alone occupies about 3/4 of an Ortlieb back roller pannier. I'm pretty sure many of the Forum members manage to tour with lighter and less bulky baggage.

I commute part time and use car days to portage. A coworker actually drives stuff to the office on weekend mornings while his family sleeps in.

Just complaining about my own packrat tendencies I guess.

I carry a flat kit and whatever clothes I need for the day. Beyond that, I can either push the bike or find the nearest bus.

can you post pictures?

I leave a pair of jeans, underthings and a couple of shirts in my desk, towel and shower stuff in my locker at work. Typically what I bring with me is a palm sized emergency kit (tube, multitool, tire levers), a container with lunch, my work ID and wallet. I could carry it all awkwardly in one hand.

I do have a garment bag that I use if I feel like dressing up at work, but that pretty much doesn't happen in the winter.

When asked by Alice why he carried a mouse trap the Knight replied, "... But if they do come I don't choose to have them running all about. You see... it's as well to be provided for everything."

Inventions in Alice in Wonderland

Sometimes I carry too much. Sometimes I didn't carry what I needed. Every once in a while I take a look thru my pack and toss some stuff add others.

how long is your commute? got a pic of yourself with your bike loaded?

First look at what you need, not what you want. What is there to "swimming gear"? Honestly, if you have a list of "swim gear" like nkfrench's

You are carrying too much stuff. Sorry, nk, but why do you need fins, a pull-buoy, kick board, and hand-paddles? Sandals, maybe googles and a towel would should be all the "swim gear" you should need if you are riding a bike to the pool. It seems to me that you have several pieces of equipment that are working at cross purposes. The fins, hand-paddles and kickboard make it so that you can go easier but you have to add the buoy to make it harder. Why not just dispense with the gadgets and adjust your swimming speed to match the intensity you need?

As to the other stuff you carry alathIN, can you leave the shave/shower/grooming stuff wherever you take your shower? I leave all my toiletries and a towel at work. I change out the towel when I feel the need and, hopefully, before it becomes sentient

I also leave a pair of shoes at work.

As to tools, carry only what you need to make minimal adjustments and repairs. You can't really do that much on the road outside of adjusting cables (slightly), tightening a loose bolt (tighten them before you start riding), making minor fit adjustments and fixing a flat. Carry only the tools you need to make that kind of repair. Some allen wrenches (4/5/6 will cover 99% of the stuff on a bike), a flat kit, a tube and a pump is all you should really need even if you are going for a long weekend.

Finally, how many locks and chains are you carrying? If your bike looks like the bike in Pee Wee's Big Adventure, you are carrying too many. Pick a single good lock and maybe a lighter one for deterrence and lock your bike where people are constantly tripping over it (not actually tripping but put it in a conspicuous spot). If people are constantly walking past your bike, thieves are less likely to try to remove the lock.

Whatever works for you is golden.

In my experience, the amount of stuff I carry tends to be related to how much convenient cargo capacity I have. In other words, rack, box, panniers whatever tend to accumulate items which I sometimes want and like to have. While conversely having less capacity I tend to work out alternatives.

Accordingly, to pack lighter just start reducing capacity and adapt. Take the panniers off, and work out how to do without something or do it differently. Then put a smaller bag on the rack. And so on. I haven't reached the extremes of pulling a trailer or racing to work with nothing on a daily basis, but I have varied between carrying a lot and very little, finally settling on a small pack with the daily change of clothes with a few toiletries.

Wow. I thought I was bad!

Daily I carry a small tool roll, a bottle of water, a couple toe straps, and my pocket stuff: wallet, phone, knife, watch. Occasionally I carry lunch, and sometimes a pair of jeans. I can fit this all pretty easily in my front rando bag or my saddlebag, depending on the bike. I considered my self to travel fairly heavy. Around here most people seem to carry next to nothing.

Thanks for your opinions. I was a competitive swimmer training with a coach and teammates. The workouts require these pieces of equipment for the different sets we do during practice. The coach doesn't tell us which sets we will do in advance for us to minimize equpment. We do not have overnight lockers nor does the pool provide this type of equipment. Competitive swimmers do not just swim up and down the pool the entire time.

Most of us think we carry too much stuff, but we don't want to leave anything behind and manage to make it work some how.

This is kind of genius. I'd never thought to carry food in a water bottle.

A burrito will fit in a water bottle cage.

I personally wouldn't want to carry that much gear every day, but more power to you. I can fit everything I need for commuting into a standard rack top bag or a moderately large seat bag like a Carradice Barley. However, I leave a lot of clothes and supplies at work, including shoes, bath towel, soap, slacks and various snack foods. On a typical day, I'll carry my lunch, wallet, shirt, t-shirt, underwear, eye glasses, batteries, tools and tire-repair gear in my rack or seat bag.

I'm down to super minimal tire repair stuff, wallet, keys, phone and wrist watch.

Thinking about a Tubus Airy, so I can bring laptop to/from.

Boy, I thought I carry too much stuff. I carry nothing compared with you. I have panniers, and I usually bring just one, and often, the only thing in it is my ipad mini. I have a tool bag strapped to my saddle which has a tube, a multi-tool, a patch kit, and a (nearly useless) micro-pump. I keep a bottle of water on the bike, even in the cold months when I don't drink from it, because it's good for emergencies.

Old setup with trailer, new set up with panniers.

The new setup looks nice! Not just losing the trailer, but the new bike as well!

Your new situation looks a lot like mine, with two full panniers on the back. On my school/work days, I'll have all my books in one, and the other will have work clothes, change of clothes and shoes (I have clipless pedals--don't wanna be clopping around in those shoes all day!), a couple of meals, toolkit, bike lock(s), and whatever else I think I might need.

I think it really just comes down to packing your bags efficiently. I have to keep everything very organized, or else it won't fit.

i carry two panniers every time i ride. lunch in one and book/ipod/ badge/ wallet stuff in the other. when it is warm in the evenings it is nice to have the space to carry some of the clothes that kept me comfortable on the way.

i dont think I have ridden to work with one pannier ever.