How do you record brick workouts - 2 workouts or multisport?

I don't have any practical experience with this. (edit - OK, a LITTLE - I've done on-the-fly multisport before)

From a device standpoint, if you use a multisport activity, it shows up in Garmin Connect as two discrete activities "glued together" as one entry. HOWEVER, each sub-activity has its own training effect associated with it.

I'll defer to someone with more experience doing this "in real life" but it seems like they're still tracked separately and multi-sport (or using the "change sport" function on the watch for on-the-fly multisport) is merely for convenience and doesn't change how training effect is calculated.

If you are asking how I do it, I just start and finish an activity when I am done. I am too lazy to set something up ahead of time.

Sometimes I run then bike, sometimes bike then run... and sometimes I do one and have something happen that I cant do the other.

I am fairly certain @CJOttawa has it right. The watch will just record the separate activities and present them as a set.

I've set up a hot key (Settings->Hot Keys->[key combo] )set to 'Change Sport'.  Now you can switch sports any and order you like. The watch still records the individual activities, but glued together. 

I have a hotkey to "change sport" also. However, I rarely use that feature because you can't edit the workout afterwards (mileage correction, trim activity, etc) although my info may be outdated now. So, if you are very good about starting and selling activities at the right moment, you should be fine using multi sport.

Also, I wish multisport had an option to see total distance covered, say running, in an ABA without if A is running. The 2nd A stays from 0miles.  Anyone know if there is a way to address this?

I don't think there is any real difference, as the effects of each sport are calculated separately, and added together.

One of the downsides of the multisport activity is that it counts the training load for each activity separately, then for the multisport as a whole, effectively double counting training load. So I generally just record brick workouts separately, and only use multisport in an actual event (to keep track of overall time), or when I am explicitly working on improving transition efficiency and time.

The other reason to record training (as against racing) separately is that you can only do structured workouts for a single activity type, not as multisport.

mcalista said:

One of the downsides of the multisport activity is that it counts the training load for each activity separately, then for the multisport as a whole, effectively double counting training load.

I'm not following here. Wouldn't you want it to do that? I don't see how it's doubling up - load is cumulative.

If I do a treadmill run, then do an hour-of-power of rowing, back to back, I WANT those to count as separate training loads.

What I think he means it if you do a run then bike it will do a training load for the run, a training load for the bike, then a training load for the run/bike combo... giving you three different training loads for the training period and you end up with basically double the training load 

If you log a load of 50 for swimming, 50 for cycling, and 50 for running, it will give a load of 150 for those, and then another 150 for the multisport, for a total of 300. Which is clearly wrong.

mcalista said:

If you log a load of 50 for swimming, 50 for cycling, and 50 for running, it will give a load of 150 for those, and then another 150 for the multisport, for a total of 300. Which is clearly wrong.

I believe it is just the way how it is shown on the mobile app, because on the report you have correct training load = it is counted only once. 

What you get - i think - when you register it as multisport, is

* one recovery time (I believe, that garmin does calculate the recovery time only based on one activity - and taking the current RT or the one from activity, whichever is higher). If you do 2 activities e.g. short run after bike, the recovery time of the run seems to be ignored, as the recovery time from bike is taken. If you do multisport - you get common recovery time.

* primary effect: if you do 1h bike and 10 min run, you will probably get sth. like Base or Tempo for bike, and Recovery for run. If you do Multisport - you will get common primary effect for both activities.