I havn't read this whole thread so forgive me if someone has said this already, but High Intensity Interval Training (HIIT) is an extremely effective and time efficient way of losing weight. Basically instead of doing a long slow session of cardio, you do a series of short cycles of maximum exertion exercise (e.g. sprinting or on an exercise bike) with rest periods in between. An example would be sprinting for one minute, then resting for 75 seconds and repeating this 8x. Each session takes about 20 mins and if you do it 3x per week you will experience an effect equal to 5 HOURS (!!!!!) of steady state (regular) cardio. It really is very effective and is thought to work by boosting your metabolism for about a day after training so you burn more calories over all.
I really reccommend it. look at the wikipedia page and try out the Tabata or Little method.
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