Physical activity is good for your state of mind but plays a minimal part in weight loss. Id say its 90% diet, 10% gym. It does help but not as much as the propaganda would have you believe. You cant outrun a poor diet.

Hi Mike,
Most TDEE calculators ask you to select an activity level (sedentary, moderately active, very active, etc) so average calories burnt from that are already factored in. If for example you chose an activity level that correlates with 3 hours of exercise a week then anything you burn at the gym is already factored in and averaged across the days.
I’d be very wary of calorie burn information from exercise machine readouts. They are estimated based on an average weight person but as we all know there is no such thing as a perfectly average person! The level of muscle mass you have and your level of cardiovascular fitness plus the amount you weigh all affect how many calories you burn when exercising.
If you want to lose weight you will get far more impact via dietary changes than exercise. Having said that I’m a big believer in exercising to preserve muscle mass. It’s very hard, if not nearly impossible to build lean muscle whilst in a calorie deficit, however you can minimise the amount of weight you lose from muscle if you exercise your big muscle groups regularly.
Apart from anything else you would have to do a heck of a lot of cardio type exercise (running, cross trainer, cycling, rowing) to burn enough calories to lose a pound of fat. Cardio exercise tends to utilise glycogen as a primary fuel source in any case so it’s a relatively inefficient way to try and lose fat.
Weight bearing resistance exercise is good for maintaining muscle mass and maintaining bone density both of which will keep you healthy and active for longer.
One last thing, don’t be surprised if your weight goes up the day after a workout. Muscles are very quick to replenish glycogen stores which come with a lot of water being retained. You will also get an inflammation response from lots of micro tears in the muscle which retains more water as they heal and the muscle is rebuilt.

@mikeFOO – You can’t trust the calorie counts on gym machines, they are likely way too high. Cardio has its place but it isn’t great for weight loss. In fact too much cardio can be hard on your lean body mass. If you want to build up the lean body mass, HIIT (High Intensity Interval Training) or strength training is much better. The muscles need to be really stressed to cause the reactions to build them up.

For many people cardio causes them to gain weight. The primary cause seems to be over compensating for the workout. It is far easier to eat more than your body uses. However, exercise in all forms typically has positive impacts on hormone levels. Still fasting is probably better for that.