Dear Fitness Coach,

I don't get it! I am 42 years old and have always kept in good shape by running (I’ve completed three marathons), cycling in the summer, and skiing and spinning classes in the winter. But all of a sudden, I am starting to see my strength dissipating. I needed my husband to open a jar of peanut butter this morning, and my upper body is getting flabby, especially the back of my arms. My husband says I am imagining all of this. Am I??

Sadly Squashy

Dear Squashy,

Tell your hubby you are not imagining anything! Starting at the age of about 30, your body starts to lose muscle at the rate of 1% to 2% each year. So it is very possible that by the time you have reached 40 years old you will have lost up to 10 pounds of lean muscle unless you have actively tried to put it back on. Your body has been in a state of war: it’s muscle versus fat, and the fat is winning. The collateral effects are loss of strength and muscle definition. Unfortunately, the cardio-based workouts that you have been doing over the years have not mitigated your muscle loss. As a matter of fact, it may have contributed towards it: whether you are training for a marathon or spinning. Once you have been doing cardio for an hour or longer, your body starts to catabolize muscle, or shift into a muscle-burning state, to maintain energy output. 

Cardio is important for mental health as well as your heart and lungs, so you do want to continue with that. However, it needs to become secondary to strength training. Weight training is the only weapon you have to win the war against age-related muscle atrophy. The most effective and efficient type of strength training is body-part splits. Each time you strength-train, work a different muscle group, as long as you work each group once a week. You do want to go heavy with weights as it is the only way to build muscle. Caution is advised though: Make sure you are executing all the exercises properly. The goal is to put on about a pound of lean muscle each month - so within the year, you can put back on the muscle you have lost over the last decade. Once you have done that, those jiggly bits will have firmed up and you will not need your husband to open up any jars for you!