If the analysis results - mainly Training effect or energy expenditure- are different in Garmin device than in Sports software, the reason is most likely in the background information. Check that you have the same background information in both the Garmin device and the Sports profile. Check especially weight, METmax and age.
If the background information is correct and identical in both Garmin and Sports, the cause is most likely the fitness level estimation. Garmin devices estimate and update the fitness level automatically according to the measurement history. In order for the Garmin device to find your most accurate fitness level, you will need to create 5 to 10 running exercises.
The more measurements there are in your measurement history the more accurate the analysis is.
In the Sports software the fitness level can be set manually. Open the person background information and add a correct METmax value.