“Bricks” refer to training on two disciplines during the same workout, one after the other with minimal or no interruption in between, just as you would do in a race. Usually a brick is a bike/run because it’s easier to set up for than a swim/bike.
When you stop biking and start running the legs feel “strange” and heavy. It feels like you are running with bricks in your shoes…thus the name of the workout. Your heart rate goes up as your body tries to switch the blood from flowing into the muscles used for biking to those used for running. This feeling is more pronounced at the start of the run and usually the legs get better as time passes – although probably never as fresh as those you have when you run without biking before it.
Brick workouts help shorten the time our legs take to start feeling more normal thus allowing you to run better and faster. Today was my first brick workout this year (not counting the sprint triathlon I did last month).
Covered 33.56 miles in 1:45:36 (19.07 mph). This was the same route that I rode last Sunday, I just cut it a few miles short. Lots of good hills. My legs were really burning coming off the bike! Avg HR = 137 bpm
Forgot to unstrap my bike shoes while I was on the bike, but other than that it was a pretty good transition.
Avg HR = 108
Covered 3.6 miles in 27:39 (7:40 min/mile pace). My legs really did feel heavy and my toes were still a little numb from the chilly bike ride (it was only 47F this morning!). After about a mile and a half I felt like I settled in to a more comfortable run. My HR was high right off the bike, then a little lower than I expected for the middle part of the run, then peaked toward the end. Not sure what was going on there. Avg. HR = 151 bpm
Avg HR = 139