The start of each swim season is the best phase to refine technique and develop aerobic capacity. In no other period of the season can you dedicate as much focused effort on developing strokes and building the base.

This Workout of the Week highlights the necessity of building a strong aerobic base and the importance of testing yourself to see what types of short rest threshold intervals you can repeatedly hold. You can read more about the different training zones used in swimming here.

Workout Statistics:

  • Distance: 3,500 meters
  • Duration: 59 Minutes
  • Focus: Testing Aerobic Capacity
  • Dynamic Intervals: Based off a 4:30 in the 400m Freestyle


A standard 300 meters of warm-up in the EASY zone allows you to expand the lungs, stretch out the body and build a feel for the water. A shorter Kick and IM set in the ENDURNACE and MODERATE zones engages all the muscles and gets the body acclimated to aerobic swimming.


Descending 50s on a semi-shorter rest interval allows the body to wakeup and get some speed going. This shorter pre-set in the ENDURANCE zone allows the body to get a feel for what’s to come.

Main Set

Repeat 100s on an interval is one of the best ways to test aerobic threshold. You’ll know how in shape you are based on the ease at which you make the interval. When you’re pushing yourself aerobically it’s important to maintain stroke technique. When in the THRESHOLD zone, you’re really pushing it.
See Also: What Are Swim Training Zones

It’s common for technique to break down under fatigue, don’t let that happen. See if you can continue to drop 5 seconds on each set of 100s. Try to take 60 seconds or less between each round to really push your aerobic limits.

Cool Down

It’s important to let your body recover and cool down after a physically fatiguing set. 100-200 meters is the minimum recommended to flush out lactic acid that was built up during the main set. A cool down and post-swim recovery can easily take up to 30 minutes or more.

Be sure to checkout 10 Steps to Swimming Smarter Freestyle and download the MySwimPro app in the App Store for iPhone and Google Play Store for Android!
MySwimPro for iPhone
MySwimPro for Android

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