Preterm infant weight gain is increased by massage therapy and exercise via different underlying mechanisms.

Objective: To compare the effects of massage therapy (moderate pressure stroking) and exercise (flexion and extension of limbs) on preterm infants' weight gain and to explore potential underlying mechanisms for those effects.

Methods: Weight gain and parasympathetic nervous system activity were assessed in 30 preterm infants randomly assigned to a massage therapy group or to an exercise group. Infants received 10min of moderate pressure massage or passive flexion and extension of the limbs 3 times per day for 5days, and EKGs were collected during the first session to assess vagal activity.

Results: Both massage and exercise led to increased weight gain. However, while exercise was associated with increased calorie consumption, massage was related to increased vagal activity.

Conclusion: Taken together, these findings suggest that massage and exercise lead to increased preterm infant weight gain via different underlying mechanisms.