Aerobic Physical Activity Guidelines for Managing Overweight/Obesity – American College of Sports Medicine 2013 Guidelines for Exercise Testing and Prescriptions
The goal of physical activity should at least be 30 minutes/day progressing to 60 minutes/day (i.e. 300 minutes per week), >5 days/week at 40 - 60+% of aerobic capacity. This goal can also be achieved through multiple daily bouts of 10 minutes duration exercise.
There is a dose effect for physical activity and weight loss - higher doses of exercise are capable of producing up to 3% or more weight loss. Any physical activity may produce some weight loss. Exercising less than 150 minutes/week results in minimal weight loss. Exercising greater than 150 minutes/week may result in moderate weight loss of 2-3kg (4.4 to 6.6lb). Exercising between 225 to 420 minutes/week may lead to 5 - 7.5kg (11 to 16.5lb) weight loss per week from baseline weight. Weight loss benefits of exercise or increased physical activity is optimized by maintenance of a relatively constant caloric intake.
Your LDL-C (i.e. your bad cholesterol) could decrease by 4 - 7% and HDL-C (good cholesterol) can increase by 4 - 25% when you implement an exercise program that will involve expenditure of 1200 - 2200kcal/week. However, fat weight reduction is required for the most favorable improvement in serum lipids (cholesterol) in patients with abnormal serum lipids (abnormal cholesterol levels).
When active young people go from >10,000 steps/day to <5000 steps/day (or as low as 1500 steps/day) in a 3 - 14 days period, it results in increased insulin resistance (initial steps on the way to development of type 2 diabetes mellitus), poor blood glucose control, increased adiposity (or deposition of body fat).
<5000 steps/day (by adults) is a step-defined sedentary lifestyle for adults. Low active lifestyle is defined as 5000 - 7499 steps per day. Physically active lifestyle is >7500 steps/day. In general, for inactive individuals, >1000kcal per week of exercise above their weekly physical activity baseline may significantly increase their HDL-C (i.e. their good cholesterol)
Resistance training can improve a variety of health-related outcomes such as muscular endurance, muscular strength, and maintenance of lean body mass. Resistance exercise training may have minimal effects on serum lipids (cholesterol). This is probably because total energy expenditure in most resistance training is often relatively moderate compared to same time spent during aerobic training of the same duration. However, resistance training exercises that involve sections of low resistance, high repetition circuit weight training performed for extended period of time (involving the expenditure of up to 300kcal or more during the session) can result in relatively high energy expenditure comparable to 30-35 minutes of moderate intensity aerobic exercise.
Additional health benefits of resistance training exercise may include improvement in chronic disease risk factors such as improvement in diabetes and heart disease risk factors.