I spent the first decade of my coaching career with an embarrassment of riches. At the University of Pennsylvania, we got fast swimmers whether we recruited or not.
At Georgia Tech, I got to coach in the 1996 Olympic pool, at one point guiding 18 swimmers over 10 short course lanes. We got pool time whenever we felt like it. You could drive a semi-truck down the deck there was so much space.
In Denmark, I was lucky enough to coach in a 50 meter pool every day, and I had twenty hours of scheduled pool time every week at my disposal to coach a senior group.
This past winter, I coached a high school boys team. We practices most of the time in a 4 lane, 25 yard pool heated to 86 degrees. We had 5.5 hours of pool time: four practices one hour in length during the weekday mornings, and a Sunday afternoon for one and a half hours.
I've never had more fun coaching. The challenge of constructing training in a much more limited time and space was exhilarating. Did I miss Atlanta sometimes? Of course!
60 Minutes of Opportunity
First things first: I think that, especially when your resources of limited, you have to avoid what is commonly called a "deficit mindset".
Deficit mindset is where you focus on the perceived weaknesses or limitations of yourself or what you are working with. In the case of limited pool time, it can be as simplistically pessimistic as saying "I don't have enough time or space to improve the swimmers". You might as well give up.
More commonly, I have seen this reflected on the poolside conversations I have with other coaches, where it can be easy to become fixated with "what's wrong" with your current situation. A good bitch session has its place, as long as you stay focused on what you actually need to do to get better.
Always Time for Skills
A younger me would have been very impatient with the amount of time offered to "condition" athletes. How much swimming can I fit into that hour? Again I argue this would have come out from a deficit mindset, a limited outlook that I needed a certain amount of swimming to help kids improve.
Instead, I chose to spend usually the first 20-25 minutes of practice working on a skill. Here was my proudest moment of the entire season:
That's right, we worked on skills! Sometimes I questioned whether it was smart, sometimes I questioned whether the swimmers were actually getting better at the skills, but in the end I could definitely see that they were, both quantitatively and qualitatively.
Every time we had the opportunity (once or twice a week) to work a pool with starting blocks, we worked on starts. Otherwise, turns, pushoffs and breakouts were the norm for the first chunk of practice.
Conditioning
This is not to say that getting "in shape" was still not a part of practice. It was. So for the final 35-40 min of practice, we often did one or two sets that focused on conditioning. Typically these were adapted USRPT sets, like 20x25 on 100 pace (or some different description to get 15-18 year old boys of varying levels to approximate 100 pace).
We did lots of 25s. Occasionally we did 50s with swimmers that swam 200s or longer. The swimmers that did the 500 did 75s a handful of times.
Against even my own expectations, the swimmers improved more on a per 50 basis in 200s than in any other distance. If I had to make tweaks, I would find something that favored their pure 50 speed more, as this is more advantageous to high school swimming. But it was also nice that many swimmers found themselves with a more diverse event set than they started the year with.
Also, we played a bunch of sharks and minnows, and a game that I learned from my coach for three months called "Russian Race".
If I was braver, perhaps I would have played Sharks and Minnows more. The best quality of sprinting I saw in any practice came when a kid saw their opportunity to burst past the shark into the wall.
"Russian Race" is a simple game. The entire team pushes off simultaneously, and the first swimmer to touch the opposite wall gets out. And on and on, until there are two swimmers racing each other for pride only.
Again, I saw great quality of sprinting in this, and kids eventually became quite tactical in when they really "went for it" to try and advance.
Is it warm down or cool down?
At the end we would usually swim a 50 or 100 easy. The nice thing about a short practice is that you don't really need to warm down. I can't decide whether I should continue to call it "warm down", since that name is pretty nonsensical.
Then the swimmers would bounce off to school (or home for dinner on Sunday) and it would be my time to swim, usually a similar practice to the one they had just completed. After all, just as I think you should ask a doctor what treatment they would give themselves, you should trust a coach more that trains you the way they would train themselves.