When you schedule a brick, you need to ask yourself four questions:

1. What is the purpose of the brick?
2. What amount of recovery is required after the brick and will it affect other quality training sessions?
3. What is the rate of return vs the risk for injury and overtraining?
4. What is the opportunity cost of the brick?

Purpose. The three most common are:

1. Develop a personal strategy for how to get your legs back, and then practice this strategy. Most people feel as normal as they're gonna after about the first 15-20 min of run. I think this kind of brick is the most important. Typically, a 15-30 min run off the bike is all that is required.

2. Teach you how to run fast on tired legs. This is a function of getting used to the "feeling" and simply getting tough enough to push through it.

3. As part of a race rehearsal, for example, a 5 hour bike and 1 hour run. This is an opportunity to practice your pacing, nutrition, and hydration plan, to see if they work for 6+ hours. I will also show you what it feels like to "go" and have to maintain yourself for that long. I think that the training value of this brick is primarily mental.

Required Recovery
Let's talk about that 5/1 brick above. A long brick like that will require a good amount of recovery time. How will this affect your other training, in particular your quality sessions? Always balance the need for the brick with its potential impact on your next, possibly more important, quality session.

Rate of Return vs Risk of Injury
I always hear of monster bricks: 5-6 hour bikes and 2 hour runs. In my opinion, there is very little return on running over one hour, while the risk of injury, overtraining, and required post-brick recovery increases greatly.

Opportunity cost of the brick
The opportunity cost of doing a short brick after every run might be a good quality track session. Or, when you did a 30 min run after a hard Tuesday bike, you missed the opportunity to do a quality 60 min run that day. This is especially true for slower runners. For these folks, a brick is often just another opportunity to run slow. I'm big believer that you need to run fast to run fast, and for these athletes I feel it is better to have well-rested quality runs. Save the bricks for later in the season, or just put a short 20 min brick after your long bike.

In general, for people with real jobs and limited recovery time, I don't think that a long brick of 6-7 hours is good for anything other than as a race rehearsal and a mental exercise. Do it once or twice, learn a few things, then stick to shorter bricks.

Rather, for most athletes, I prefer to do one brick per week: 20-30 minutes after the long bike. This is just long enough to force you to develop a strategy, but not so long that it affects your other training.

Strategy for Bricks: Half and Ironman Training

1. Make your transition from bike to run as short as possible. This makes the training realistic, and also gives you less time to talk yourself out of it :)

2. Do every brick in training exactly how you plan to do the real thing on race day: have your shoes, hat, nutrition all set up and ready to go. Put your head in the game and think.

3. For most people, it takes about 10 minutes for issues to work themselves out. During this time, hold back and let your body settle in to running. Run with a high cadence and quick strides.

4. After about 10 minutes, start to accelerate and feel out your pace. After about 20-30 minutes, you should be running at your goal race pace.

5. Do bricks on an out and back course. Hold back and settle in the first half, then negative split the second half.

6. Finish the run with a quick acceleration, so that you feel good about your speed and your ability to run off the bike.

Bricks for Shorter Races
If you are trying to be competitive in shorter races, you don't really have time to let your body adjust and settle in. This strategy above is good for most training bricks. However, as you get closer to race day, I recommend Interval Bricks.

Interval Brick
Set up a transition area at a track, in your garage, or in a relatively secure area. Warm-up with a 10-15 min spin. Main Set: 3 x Interval Brick (ride 10-15 min as an out and back, allow your heart rate to rise to Zone 5a on the second half. Finish the bike at your transition area and quickly transition to the run. Run 5-7 min as an out and back at goal race pace, negative split. Immediately repeat the interval. 10-15 min easy spinning as cool down.

This is an intense session and should replace either your BT bike or run session for the week. You can play around with the length of the bike and run segments to better fit your goals and abilities. The purpose of this brick is to teach you to just push through the difficulty of running fast off the bike. If you want to be competitive at the shorter distances, you don't have time to settle in. Your legs just have to catch up.