Planks have long been considered one of the best exercises for your core. In addition to your abs, this move engages your back, quads, and hamstrings, making it a great full-body exercise for runners. To do it, get into the “up” part of a push-up, with palms on the floor directly under shoulders and legs extended behind you, forming a straight line from head to heels. Hold for 10 to 30 seconds, keeping abs tight. Do 2 or 3 sets.
Clamshells work your hips and glutes, parts of the body that runners regularly need to activate. To do them, start out by lying on your side with legs stacked and knees bent at 45 degrees. Rest head on arm; place top hand on hip. With inside edges of feet touching, lift top knee as high as you can without shifting hips or pelvis. Pause; lower knee. Do 2 or 3 sets of 10 reps per side.
3. Side squats
Side squats are a great way to strengthen your outer highs, hips, and glutes. To do, stand with feet hip-width apart, hands on hips; squat. Stand; move left foot a step out. Squat again; step left foot in as you rise. Continue, alternating sides. Do 2 or 3 sets of 10 to 12 reps per side.