Exercise Keeps You Young

We’ve been over this before: one of the best things you can do for your health is to exercise regularly. No matter your age, exercise keeps you more vibrant and less prone to illness. Exercise makes you happier, stronger, more energetic, mentally sharper, and gives you a better night’s sleep. And now, according to the latest headlines, regular exercise actually keeps you young.

Okay, as usual some of these headlines are overselling things. According to the study that inspired this latest round of news, what exercise really does is keep certain components of the immune system as robust in older exercisers as they are in young adults — but that’s still a pretty big deal.

The title of the study, published in the journal Aging Cell, is a snoozer: “Major features of immunesenescence, including reduced thymic output, are ameliorated by high levels of physical activity in adulthood.” And just reading passages like the following might be enough to knock a few years off your lifespan:

Other hallmarks of T-cell immunesenescence include the following: accumulation of CD28-ve CD57+ve T cells with shortened telomeres and reduced proliferative capacity (Di Mitri et al., 2011), which also acquire NK cell receptors such as KLRG1 (Weng, Akbar  &  Goronzy,  2009)  increasing  the  risk  of  autoimmune responses, skewing of T-cell responses towards Th17 cell differentiation (Ouyang et al., 2011). 

We’ll try to summarize the study in (mostly) plain English:

Aging is known to be accompanied by a decline in “immune competence,” which leaves us at increased risk of infection and chronic inflammatory disease, poor vaccine efficacy, failure to maintain immunity to latent infections, and increased autoimmunity. None of that is good.

Past studies that have shown this age-related decline, however, have not taken into account the effects of regular exercise on immune competence. Since the majority of older adults are sedentary and fail to get the standard recommendation of 150 minutes of aerobic exercise per week, we can’t know for sure how much of the immune decline is due to aging and how much is a consequence of a sedentary lifestyle.

And so this study looked at three groups: healthy, highly physically active older cyclists (aged 55–79); healthy but sedentary adults in that same age group; and healthy young adults (aged 20–36).

We won’t get into the technical details — the T-cell subset distribution, the thymic output, the RTEs, the cytokine production, the CD3 stimulation of PBMCs. There’s no need for the average human to wrap their brain around all that.

The important thing to know is that, while the sedentary adult group showed a significant decline in these components of immunity, the older adults who exercised regularly showed for the most part no difference from the young adult group. Immune competence is maintained by regular exercise.

And thus the headlines: Exercising Into Old Age Can Keep Your Immune System Young; Physical Exercise Fights Illness By Keeping The Aging Immune System Young; Cycling Can Keep You Young in Wide-Ranging Ways; and Exercise Keeps Your Body Looking Young.