Personal training, ie pure physical activity without diet changes, is not an effective way to see weight loss in a client.
Clients are often allowed to check “weight loss” as a goal with exercising for most personal training services, which are generally cheaper than my services as a registered and licensed dietitian. It is frustrating having to compete for weight loss clients against personal trainers who may not know that weight loss is only achieved with diet changes, especially considering the lack of education of a personal trainer in approaching dietary changes with people.
Scientific studies1,2,3 and my experience in training people who have not made any diet changes in spite of significantly increasing their physical activity capacity demonstrate that there must be a dietary caloric deficit in order to lose weight.
Sure you will become healthier on the inside, gain some lean mass and thus reduce body fat percentage (without weight loss), and your clothes may fit better from exercise (or you may have to buy new ones because the old ones no longer fit), but to see the number go down on the scale, you need to change your eating habits. Moderate aerobic exercise is great for increasing HDL cholesterol and improving blood sugar sensitivity. Resistance training is also great for building bone density, strong muscles, coordination, and improving blood sugar sensitivity. However, exercise alone will not make you lose weight!
- Int J Obes 21: 941-, 1997.
- Int J Sports Nutr 8: 213-, 1998.
- Am J Clin Nutr 54: 56-, 1991.