WORKOUT KEY

BASE BUILDER
Today, burn lots of calories doing steady-state work to build your aerobic fitness base. Perform 35-45 minutes of running, walking, stepping or any type of continuous activity at RPE 5-6 (see the RPE chart below). Calories burned: 300-385**

ENDURANCE BOOSTER
Today, perform long intervals of higher-intensity work, improving your ability to sustain a more difficult level of exercise so you can burn more calories in your workouts with less noticeable effort. Do two 10-minute intervals at RPE 7-8, separated by 1 minute of "working" recovery (meaning it's still a challenge) at RPE 5-6, for a 21-minute workout. Calories burned: 270

POWER BLASTER
This month's emphasis is on improving your staying power in your workouts and giving your lower body a strength boost. Alternate 2- to 4-minute intervals at RPE 8-9 with "working" recovery periods of the same length at RPE 5-6 for a total workout time of 30 minutes. Calories burned: 340

LIFESTYLE
Today, get all your exercise in the form of lifestyle activities. Last month, you tried for 11,000 steps a day; this month, shoot for 12,000 steps a day. Some ideas on how: Wash your car, walk to lunch with co-workers, rearrange your furniture. (For more ideas, see April and May's cardio plans.*) To keep track of your steps, use a pedometer or keep an activity log. (Every time you perform 5 minutes of activity, give yourself a point. Aim to get about 24 points in your log every Lifestyle day.) Calories burned: 325

**Calorie estimates are based on a 140-pound woman.