#aCienciaCerca - 28. Actividad física y su relación con la salud y el cerebro, por Francisco Ortega

Summary

Francisco Ortega argues that physical fitness is an important, modifiable indicator of health—not merely a by-product of body weight. He discusses its relationship to physical and cardiovascular health, mental health, brain structure, cognition, and academic performance.

Main ideas and evidence

• Low fitness is a significant health risk.

  • The talk focuses especially on cardiorespiratory fitness: the ability to sustain activities such as running or cycling.
  • Very low cardiorespiratory fitness is associated with a higher risk of death from cardiovascular disease, cancer, and all causes compared with medium or high fitness.
  • Muscle strength is also presented as an important predictor, comparable in significance to established risk factors such as obesity and hypertension.

• Study of Swedish adolescents and young adults

  • In a collaboration with researchers in Sweden, more than one million adolescents were followed for 25 years.
  • Researchers examined muscle strength, including leg-strength tests and handgrip strength, and compared the results with mortality and conventional risk factors.
  • Very low strength was associated with higher overall and premature mortality. The speaker also reports associations between low strength and psychiatric diagnoses, psychiatric hospitalization, and suicide mortality.

• Fitness can matter more than weight alone.

  • The talk contrasts people who are slim but unfit with people who are obese but fit.
  • A review published in 2016 in Circulation Research is cited as showing lower cardiovascular mortality risk among fit people with obesity than among slim people with poor fitness.
  • This pattern was reported whether obesity was assessed by body mass index, body-fat percentage, or waist circumference.
  • The broader message is that being slim does not guarantee good health; fitness is an important factor in its own right.

• Physical fitness is associated with brain structure and cognition.

  • A 2008 review in Nature is described as finding consistent evidence linking better fitness—particularly aerobic fitness—to better cognition in children and adults.
  • The speaker notes reported structural differences in the brains of fitter people, including areas such as the hippocampus and basal ganglia.
  • Research from Granada, including the NUGIL project and the Active Brains study, found that children with higher cardiorespiratory fitness had differences in brain structures and greater development of gray matter in areas related to executive function, reading, and working memory.
  • In the Active Brains findings presented, several fitness components—such as aerobic capacity, strength, speed, and agility—were positively associated with executive function. Children who did better on fitness tests also tended to perform better academically.

• Exercise has wide-ranging benefits.

  • The speaker describes physical activity and improved fitness as being associated with benefits across multiple dimensions of health.
  • Examples cited include better strength, lipid profiles, and bone health, as well as fewer symptoms of depression and anxiety.
  • He characterizes exercise as a kind of “polypill” because of its broad potential benefits.

Practical lesson

• Physical fitness can be improved through training, so it is a modifiable health factor.
• Exercise should be prescribed and carried out appropriately: the type, duration, and frequency matter.
• The speaker recommends seeking guidance from qualified sports-science professionals or physical-education teachers, particularly to gain benefits while reducing risks from poorly planned activity.

Speakers and sources featured

• Speaker: Francisco Ortega.
• Research and publications discussed by the speaker:
  • A study with researchers from the Karolinska Institutet in Sweden, following more than one million adolescents for 25 years.
  • A 2008 review in Nature on fitness, cognition, and the brain.
  • Research from Granada associated with the NUGIL project.
  • The Active Brains study, begun in 2013.
  • A 2016 review in Circulation Research on fitness, obesity, and cardiovascular mortality.