One-Hour Workout: Session in a Bottle
You can drink from this workout—and you can swim it. Yes, you read that right…
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This week’s one-hour workout is taken from the side of a bottle. Swim coach Dan Bullock at Swim For Tri in the UK came up with this innovative idea after seeing so many swimmers with their workouts scribbled on soggy pieces of paper on the pool deck. The session in a bottle workout itself—a block of 25×100—can be as challenging as you’d like to make it.
Bullock says: “The beauty of the main set from our ‘session in a bottle’ is its adaptability; when we swim this set in our fitness sessions it often takes various forms.”
We have it in its most simple format here: After an easy 10 minute build warm-up swim, it’s time for the main set, which is a progressive set of 100s that goes from 1×100 all the way up to 5×100. Each time there’s an increase in distance, there’s also an increase in rest (see main set description below). Do not be afraid to adjust these rest intervals (and the number of 100s) according to fitness and ability. For example, you could go as far as the 4×100 if you prefer.
The goal is to build the pace toward the 5×100 and then hold that pace for the remaining 100s: 4×100, 3×100, 2×100, 1×100. As you come down in distance, you’ll come down in rest. Of course, if you want to make this set harder (we know there are some of you out there who like that!), then you can decrease rest as you increase distance—but that’s probably best left to closer to race season and isn’t an off-season project.
Bullock adds: “Start steady and build the pace towards the 5×100 in the middle and then juggle the decreasing repeats with the decreasing rest. This makes for a very hard block of work if you aim to hold the pace you achieved in the middle five through to the final swim.”
If you’re looking for some added variety, feel free to pull the even blocks of 100s (2×100, 4×100, etc.).

Session In A Bottle
Warm-up
10 mins easy swim
Main Set
1×100 with 10 rest
2×100 with 15 rest
3×100 with 20 rest
4×100 with 25 rest
5×100 with 30 rest (build pace to here and then aim to maintain this pace throughout the rest of the set)
4×100 with 25 rest
3×100 with 20 rest
2×100 with 15 rest
1×100 with 10 rest
Cooldown
5-10 mins easy swim