Hi I'm 15 years old & decided to start this as I realised how unhealthy I am. I was smoking for a year, I quit smoking started c25k & changed my eating habits 3 weeks ago. I find every work out hard & only complete 3 a week no more! I went to start w3 d1 today completed 2 of 4 rounds & gave up☹️ . I was breathing so heavily & was afraid I was going to have an asthma attack ! After a little nap I felt fine again & can breathe normally. I really don't want to give up