Bricks are a term used to describe transition training for triathletes. The usually refer to a bike/run brick, but can also be used to refer to swim/bike bricks or other combinations.
The term came about in the late 80’s early 90’s. There are a couple of idea’s about where the term came from. Some claim term is a nod to Dr Matt Brick who won the world duathlon champs in both 1991 and 1992 (back in the old school 10/60/10 format). And other claim it comes from a group of top tier triathletes including the likes of Mike Pigg, Mark Allen, Scott Molina and a few hangers on, who used to train together, apparently someone in the group used to sing “Another Brick In The Wall” by Pink Floyd whilst training. The idea that the training session was brick that was helping to build their wall of training.
Regardless of where the term came from, it provides a vital training sessions that prepares the body, physically, mentally, and neurologically for multisport events (whether triathlon, duathlon or something like the Coast to Coast or an adventure race).
As the athlete moves from one discipline to another – in the case of a triathlete from swim to bike to run – the body needs to ensure that the extra oxygen demands due to exercise are being met. At peak activity working muscles may require as much as 100 times more oxygenated blood than they do whilst at not exercising.
Whilst swimming the greatest demands for oxygenated blood are for the back, shoulder and arm muscles. When you move onto the bike the greatest demands are for the glutes and quadriceps. Then for running the highest demand is for the calves and hamstring muscles.
The biggest issue for triathletes is moving from cycling to running. During the bike leg of the triathlon -which is the longest in both duration and distance (for most triathletes at most events, yes, some Ironman athletes have a bad day and their run takes them longer than their bike leg did) – the cycling muscles (glutes and quads) are sending messages to the brain saying deliver more oxygen. So the brain responds by opening (or keeping open) the blood vessels transporting oxygenated blood to the cycling muscles, and limiting the blood flow to other areas where it isn’t so essential, such as digestive organs. The cycling muscles keep sending these messages to the brain continuously, whilst they continue to receive an input that we are still cycling.
Then we get to the transition area and before we know it, we are off the bike and running. The cycling muscles can be a bit slow on picking up on the fact they are no longer cycling and continue to send the message to the brain saying “send more oxygen” but the running muscles are now saying “wholey F***, we need oxygen, send it to us now“. Your legs feel like jelly, and there is a conflict between the quads & glutes; and the hamstrings & calves.
Eventually, after a bit of analysis and decision making the brain works out that you are now running and not cycling & starts to send oxygenated blood to the running muscles. That can only effectively occur once the oxygen debt that the glutes and quads developed had been repaid. The body can split the supply by reducing what it was giving to the cycling muscles and increasing what it gives to the running muscles whilst this oxygen debt is being repaid. A bit like the tap slowly being turned off for the cycling muscles and slowly being turned on for the running muscles.
Once the new reality of running is being fully supported with an appropriate supply of oxygenated blood we find that the jelly leg feeling dissipates and goes away.
The good news is that we can train this system and we can also modify our behaviours so the impact of the transition isn’t so pronounced.
Firstly by including regular transition (or brick) workouts into your training the body adapts and gets familiar with the process of transitioning blood flow from cycling to running muscles.
Secondly, by decreasing your intensity in the last few minutes of your ride the blood supply required by the cycling muscles can be reduced, meaning there is a great availability of oxygenated blood that can go to the running muscles and the cycling muscles will have less oxygen debt to repay before you can hit your running stride.
The other thing you can do is ensure that your cycling cadence is relatively high (above 90 rpm), this will mean that as you start your run, the legs are used to turning over at that rate and will continue to turn over at that rate. If you come into transition grinding along at 70 rpm, you will start your run with a slow laboured gait with a cadence of about 70 rpm.
Over the coming weeks I will be publishing a regular Brick workout each Monday that you can do assist with preparing your body with the demands of transition for future races.