My Garmin connect app and Strava app are connected however my heart rate data is different.

My Garmin is connected to Strava and often my Max speed is different 2-6mph difference from sprints.

How different? Post screenshots that shows the difference. 

For example, during a speed workout yesterday Strava’s data said my max heart rate got up to 188 but the Garmin connect app said 181. 

Post screenshots so we are looking at the same data.

The Connect activity data and Strava should say the same (maybe off by 1-2 heart beats due to rounding). If you look in My Day and the heart rate card the data can be very different since those values are two minute averages.

On speed:

Garmin's timing doesn't add the time spent while the activity was paused while Strava does and adds it to the lap when it happened. So cool for realistic resting period data!

Garmin and Strava handle stopped time differently so you need to consider that when comparing them. Don't stop the timer during rest. Just keep it going. It is a part of the workout. Strava also do some smoothing of the data.

Just accept that it will be different. They are both correct in their own ways.

e7andy said:

Strava also do some smoothing of the data.

Oh, good to know. But which one is more reliable? I was excited for a new max speed but Strava's seems more realistic (dang!).

e7andy said:

Just keep it going.

It's a countdown timer. When it ends it jumps to the next step with a Target speed. I just press pause when I feel I need more rest and was amazed of Strava collecting those minutes for me to review.

Frederick said:

But which one is more reliable?

Hard to know. You will have to look at the graphs and compare with how it felt.

Speed is a calculated value from the time between a number of positions. So, it depends a lot on the accuracy of the logged positions. 

I've never tried this, but would using the multiband satellite option give a better reading? I've always avoided it because it uses more battery.

The positions will be more accurate with multiband.