An interval in swimming is a set time that allows you to depart on a consistent schedule. The point of intervals is to give you rest so you can maintain your form, recover so you can maintain faster speeds and train your body to swim faster. For example your interval might be 2:00 for 100s freestyle. If you are holding 1:40 for your first 100s in the set you will get 20 seconds rest. If you get slower as you go you will get less and less rest. This is a great way to challenge yourself! If you give yourself a set amount of rest, like 20 secs per 100 there is no motivation to stay at the same speed or get faster and no deterrent to getting slower! Picking an interval before your set gives you something to work towards. Holding a consistent pace throughout a set is a skill in itself, it helps you better know your fitness level. How much rest you take between repeats depends on the goal of the set and on your fitness level. Usually long rest between sets indicates you should be working hard each repeat. For instance, if you are doing all out 100s (where your heart rate might reach 95% or more of your max) you might take 3 minutes between each one, however, if you are doing an aerobic set (where your heart rate stays between 65-75% of your maximum) you might take only 10 seconds, just enough time to recover a little, maintain your form and stay consistent.
Test Set Example:
10 x 100 Freestyle Rest:20-30 secs between each 100 e.g. use an interval of 2:10 if you start with a 100 that took you 1:40
Goal: go at a speed that you think you can hold for all ten 100s. Your heart rate should be aerobic. If you’re one those folks that have “one speed” go at that speed to get a baseline average speed.
Pace Set Example:
3 x [3 x 100 descend by time 1->3 Rest: 30 secs after each 100]
Take an extra 1 minute rest between sets of 3.
Goal: increase your effort from 70%, to 80%, to 90% on the 100s within each round. When you do your 90% effort experiment with different ways to increase your speed. My suggestion is to try to feel powerful and like you are holding more water rather than increasing your stroke rate. Pace yourself through the fast 100 by feeling easy speed in the first 25-50 yards and put more effort in as you go. Your first 100 at 70% should be about the same time as you can hold for the 10 x 100 test set or a little faster.
Training Set Examples:
Use your baseline time per 100 to set your interval (i.e. baseline time + R:seconds = interval). Try to hold your average speed faster than that baseline time.
Always take time to warm up and work on drills so you are focused on your technique before you start into a main set like this.
Aerobic: keep your heart rate around 65-75% of maximum
Choose an interval with the amount of rest shown as your guideline – roughly 10 secs over your baseline time per 100
400 – R:40
300 – R:30
200 – R:20
As you repeat this set over time try to reduce the amount of rest per 100 you get by setting the interval faster. Try to keep your same average speed as you get less rest but keep the same heart rate level.
Anaerobic: get your heart rate up to 85-90% of maximum
3 x [5 x 100] R:30
Take an extra 1 minute rest between sets of 5.
Set #1 – all five 100s at 70%
Set #2 – all five 100s at 80%
Set #3 – all five 100s at 90%
As you repeat this set over time watch your average times improve for the same % of effort.