The sensation of fatigue and how hard you will push yourself is very relative. Some people enjoy pushing themselves very hard and others not much at all. What matters is that you are making progress. I generally advise my new clients to start out not pushing very hard at all. If you are new to exercise you will still make progress. As you become more fit you will get used to the sensation of exercise and you will probably want to push yourself harder. Having said that it is always advisable to have some rules in place for how hard to push to avoid injuries. I will review those with you as part of your training. * You will never be expected to keep up with anyone else. This is why I don't offer traditional fitness classes where everyone follows along. It doesn't honor your current physical level.