Using resistance bands during baseball conditioning can help you increase base running speed by building leg strength, hip flexor strength, and increasing flexibility and balance, and can also help improve stride length and stride frequency. There should always be a warm-up with 5-10 minutes of aerobic exercise. Training sessions should be 2-3 days per week. Resistance bands can add muscle-building power to most types of workouts. They're also excellent for rehabilitating muscles after injury. Resistance bands come in several strengths, making them highly usable by most people.