I've been doing Insanity for almost 3 weeks shouldn't I have lost weight or noticed my body becoming super toned?
The real answer is NO... it typically takes about 6 to 8 weeks to notice any changes in your body which is why people tend to lose interest just before the magic happens.
How do we build muscle?
From different exercises and resistance training, it leads to trauma or injury of the cellular proteins in the muscle. This prompts cell-signaling messages to activate satellite cells to begin a cascade of events leading to muscle repair and growth. The adaptation of muscle to the overload of stress of resistance exercise begins immediately after each exercise bout, but often takes weeks or even months for it to physically manifest itself. So, DON'T GIVE UP!
Another reason to keep motivated is that muscle increases our basal metabolic rate. The more muscle we have, the faster our metabolism which is important as we age. Did you know that our metabolism actually decreases by 2-3% every decade?
Staying consistent with your exercise routine can shape and tone your body. Remember that muscle weighs more than fat.