Targets calves, thighs, hips, butt; boosts endurance and agility.
Park yourself next to a balance beam or another low ledge, such as the side of a sandbox, then hop sideways over it. Jump back and forth continuously for one minute, landing with knees slightly bent to absorb the impact.
Stand facing a bench or a low jungle gym platform with abs contracted and hands on hips. Place right foot on the platform and step up as you lift left leg in back of you, kicking left foot straight back to engage butt muscles. Return left foot to ground, keeping right foot on platform.
Stand about 2 feet in front of a swing, placing both forearms in the middle of the seat. Slowly lean forward, pushing the swing away from you until body is straight. Hold for three seconds. Next, use arms and abs to bring the swing back in front of you.
Sit at the top of a slide with legs outstretched. Hold onto the bar above your head and lean back to engage core. Bend legs and use abs to slowly bring knees up toward chin; hold for three seconds, balancing on tailbone. Return to start position, tapping both feet on the slide. Do a total of eight to 12 reps.
Climb halfway up a jungle gym ladder and lightly grasp the handrails. Slowly lower butt until thighs are parallel to the ground; hold for three seconds, keeping abs engaged and squeezing lower-body muscles. Carefully return to start position.
Do two to three sets of eight to 12 controlled squats, resting between sets if necessary.
Position body under any low play-set bar. Using an underhand grip, grasp it with hands at least shoulder-width apart. Place feet as far in front of you as you can. With legs firmly planted on the ground and abs tight, slowly bring chin toward bar. Hold for three seconds, then slowly return to full arm extension.
Do two to three sets of eight to 12 repetitions.
Originally published in the October 2010 issue of Parents magazine.