Weightloss during workouts?

[monique_]

I understand that you lose a 100-300g during a workout because of water and sweat. Today I started at 70.5kg and by the end of my workout I'd burned 623 calories and weighted 69.9kg. Isn't it a bit drastic? I'm not sure how I feel about this drastic of a weightloss within an hour and a half.

Thanks guys.

[Dominique]

You can ignore any weight fluctuation (whether it’s up or down) that occurs within your workout. Focus on how you feel and make sure you stay hydrated by drinking enough water. If you have been sedentary for a long time and are new to exercising, take it easy at the beginning. The more likely and meaningful consequence of your intense workout will be muscle soreness tomorrow or the day after tomorrow. Also remember the energy expenditure reported by your Fitbit is an estimate. This is especially important if one of your reasons for exercising is weight loss and you are also counting your intake.