Take a tour of all the varieties of kale

Q: I finally gave in and used kale in a salad. It was tough and bitter. What is all the enthusiasm for this nasty green about

Julian H., Montgomery, Ala.

A: Hail kale! Raw or cooked, it’s packed with a good dose of vitamins C and A, plus potassium, lutein and B6 in every cup. And it’s tasty — if you select the right variety for the recipe you’re trying. Some kinds are wonderful au naturale, others require cooking; some stems can be eaten, others not at all.

— Curly kale has tough stems that you need to remove before braising or sauteeing the leaves in olive oil and garlic. If you eat it raw, you need to massage the leaves (no kidding) with a touch of salt and lemon juice to break down the hard-to-chew fibers.

— Tuscan kale is more tender than the curly type, but to get the best flavor and texture, you still have to remove the stems and either massage it before adding to a salad or use it in soups or stews. Also, it’s great chopped into squares, coated in olive oil and roasted to make chips, or — a favorite of ours — added to smoothies with other veggies.

— Red kale can have red-colored leaves and stems or just reddish stems. It’s prepared like curly kale.

— Baby kale, stems and all, is made to add to a salad of mixed greens or to a stirfry.

— White flowering kale is great added to soups or braised. Purple flowering kale has bitter stems, so remove them, but it’s good raw or lightly cooked.

Q: I keep hearing that consistent, moderate exercise is the healthiest way to get or stay fit. But what is moderate? I have no idea if I am doing too little or too much.

Gigi R., San Francisco, Calif. A: As a rule, moderate intensity exercise is defined as activity that pumps your heart rate 50% to 60% higher than it is when you are at rest. Your aim is to do 150 to 300 minutes of physical activity a week. But if you have been sedentary or have any medical condition, you should start slowly with 10 to 20 minutes at a time and build up gradually — with your doctor’s advice.