Can several 15-minute anaerobic exercises per day really help losing weight?
By definition, anaerobic exercise consists of highly demanding activities that even highly trained athletes can maintain only for a short time. The 100 meter dash is an example because the race begins and ends without the competitors taking a breath. In fact, "anearobic" means without air. Elite athletes often can run 400 meters without taking a breath but such is far beyond what most can do. Anearobic exercise is for people with a high levels of fitness.
Aerobic exercise, on the other hand, includes activities that can be intense but not so much so that you cannot take breaths. Aerobic, then, means with air. Such exercise activities, then, can be sustained for 15 minutes at a time, at least by people sufficiently trained. These exercise styles are those that allow you to breathe all along the way. An underlying level of fitness, however, must be reached before undertaking 15 minute bouts of aerobics of any kind unless the activity is very mild.
As for losing weight, using exercise alone to meet weight loss goals is quite discouraging. Much more efficient is to combine sustained (aerobic) exercise with careful monitoring of what and how much you eat.
Good luck to you,