One of my recent Wellness Garage consultations was with a triathlete and marathon runner. During our review, we looked at his six core behaviours (nutrition, exercise, sleep, mindfulness, relationships and purpose). When it came to exercise he thought that he was covered from a health perspective. Very good evidence shows that runners live longer than non-runners and that aerobic fitness is one of the most important biomarkers for vital longevity. His aerobic exercise at over 300 minutes per week, and his accomplishments including several Ironmans indicated that he was a highly developed aerobic athlete. The problem for me was that he was not doing any resistance work. We discussed the evidence and I told him that he was missing something vital from his program. The best illustration of this comes not from any population studies, but from a serendipitous twin study done by some Cal State kinesiologists and published in 2016.
Two identical twins with over 35 years of very different exercise behaviours were examined for key health outcomes and biomarkers.
One twin was a track coach and competitive masters runner training in endurance sport for 35 years, logging close to 40,000 miles. His identical twin brother was a truck driver whose only recreational physical activity has been 20-30 min walks, 3 to 4 times per week.
These brothers were tested for strength (hand grip and quadriceps), aerobic capacity (VO2 Max) as well as body composition (lean muscle mass, body fat % and bone density).
At first glance, looking at the profiles of the two brothers it seems obvious that the Ironman should test better than the sedentary brother on every parameter, but that was not the case.
As expected the trained twin had a higher aerobic capacity (VO2 Max) and lower body fat.
Surprisingly, the untrained twin was stronger in both grip and leg strength.
Both had identical findings for lean muscle mass and bone density.
The study concluded that endurance sport improves aerobic capacity and body composition by decreasing body fat BUT is associated with lower strength in both hand grip and very surprisingly leg strength.
From a health and longevity stand-point both aerobic capacity and leg strength are independent predictors of mortality. Training can improve both, but training adaptations are specific to the imposed demands.
Therefore the optimal strategy to maximize health and longevity must incorporate both strength and endurance training.
This study really drives home the point, runners and triathletes who are not doing strength training may actually be weaker than if they were sedentary! If you are serious about your health (not to mention performance), adding strength work makes sense.
With my triathlete client, we have recommended a strength training program to develop leg, back and core strength. This program, with emphasis on heavier weights lifted using the large muscles of the body, is an excellent way to increase mitochondrial density and improve metabolic health, which is probably one of the reasons why strength is associated with better health and longevity.
PHYSIOLOGICAL PROFILE OF MONOZYGOUS TWINS WITH 35 YEARS OF DIFFERING EXERCISE HABITS
PDF Download available from: https://www.researchgate.net/publication/316337441_PHYSIOLOGICAL_PROFILE_OF_MONOZYGOUS_TWINS_WITH_35_YEARS_OF_DIFFERING_EXERCISE_HABITS
Accessed Nov 25 2017
Dr. Brendan Byrne