Outside Magazine website highlighted recent studies published in the Journal of Strength and Conditioning Research that show passive-resting activities like walking can reduce heart rates in as few as 25 seconds. Even better, they can lead to better performance in subsequent legs of your run, allowing you to gain more ground than if you’d pounded along the whole time with no breaks.
When you arrive at the finish line of a any race that involves running (road, trail, triathlon, obstacle), no one asks how you got there. The only measurement of your performance is your finish time. If taking walk breaks lowers your heart rate, allowing you to run stronger and faster, then why not?
200yds. reverse IM
100yds. swim choice
100yds. kick choice
4x(50yds. free + 25yds. choice)
the free is progressive + 10sec. rest
the choice is fast
start with 20sec. rest for 1st round and reduce rest by 5sec. for each subsequent round + 100yds. easy after each round