We all have a friend who can eat or drink whatever they want and never gain an ounce. Some, on the other hand, can’t even look at a piece of cake without gaining five pounds. No fair! What gives? It’s the differences in metabolism. How fast your metabolism functions is determined mostly by your genes. However, age can also affect metabolism, often slowing as we get older.

What exactly is metabolism? It is the range of chemical processes in the body that convert what we eat and drink into the energy we need to survive. We need that energy to function: to breathe, to circulate blood, to grow and repair cells, among other things.

So, what can we do to raise our metabolism if it has become sluggish? Try these suggestions to rev up your engine.

Eat More Protein. Protein is made up mostly of amino acids which are harder for our bodies to break down, thus requiring more energy to process (the high “thermic effect”). This can raise your metabolic rate by 15-25% compared to your body’s reaction when processing other types of food.

Pump More Iron. Weight training is a great way to boost metabolism. Muscles burn more calories than fat, even at rest. So, grab those dumbbells and start building more lean muscle tissue.

Try High Intensity Workouts. When you work out at a very high intensity, you create a huge metabolic disturbance. Studies have shown that this type of training uses fat rather than carbs for energy and can keep your metabolism raised for hours after your workout is finished.

Stay Hydrated. Chronic dehydration is associated with a suppressed metabolism. Water is key to ensuring that your body functions properly. Over 70% of your muscle consists of water, so if you are not sufficiently hydrated, your muscle ability to generate energy is greatly limited.

Following these tips and generally trying to stay as active as possible can boost your metabolism. That boost can make you feel more energized, as well as help maintain a healthy weight.