Aerobic and resistance training affect skin aging differently

According to a new study published in Nature science reportswhile both aerobic and resistance exercise improve some aspects of skin aging, only the latter is able to increase skin thickness [1].

Exercise and skin an overlooked connection

The skin is the largest organ of the human body and provides a barrier that protects us from environmental hazards, such as pathogens, sun rays and pollution, which also means that the skin is one of the first organs to initiate aging. Skin aging is characterized by thinning of the skin, degradation of the extracellular matrix and increased cellular senescence.

Exercise is an essential part of any life extension strategy. Its health benefits are numerous and new discoveries keep coming. However, the role of exercise in skin aging has been largely overlooked. While one study found that aerobic exercise lowers IL-15, a regulator of skin aging [2]the effects of resistance training on skin aging are largely unknown.

Thick and healthy

In this new paper, the researchers describe a 16-week randomized study of 61 healthy sedentary middle-aged Japanese women. Participants were divided into two groups, one undergoing an aerobic training (AT) regimen and the other undergoing a resistance training regimen. Blood samples were taken from the participants before and after the surgery.

Both interventions did what they were supposed to do: AT significantly reduced body weight and body mass index (BMI) and significantly improved peak oxygen uptake (VO2peak), a measure of aerobic capacity, while RT increased lean mass and muscle strength.

In regards to skin aging, both AT and RT improved skin elasticity and superior dermal structure. However, only RT increased dermal thickness.

To explore the mechanisms by which the interventions improved skin aging, plasma taken from resting blood before and after the 16-week training session was added to cultured human dermal fibroblasts and the expression of dermal genes related to the extracellular matrix (ECM). .

Here too the difference between the two types of training was evident. Both AT and RT enhanced the expression of several ECM-related genes, such as those involved in collagen production, but the overlap was incomplete. AT affected multiple collagen-related genes, while RT affected biglycan, a protein that interacts with collagen fibers in the ECM, contributing to tissue structural integrity.

Since biglycan was one of only two proteins affected exclusively by RT, and it has been linked to skin health by previous research (GM mice with reduced biglycan production are known to have thinner skin) [3]the researchers focused on this factor.

Exercise clearly influences the expression of genes in skin cells via circulating factors. The researchers measured 1480 of them and found three that negatively correlated with the post-RT increase in biglycan levels. Incidentally, all of these factors are known to be pro-inflammatory. When applied to human dermal fibroblasts in vitro, the three factors caused a decrease in biglycan levels. However, the researchers admit that animal studies are needed to clearly confirm the skin-rejuvenating mechanism of RT.

In conclusion, a 16-week intervention with AT and RT demonstrated that both training interventions counteract skin aging by improving skin elasticity and upper dermis structure. Furthermore, RT increases dermal thickness by inducing a decrease in circulating levels of CCL28, N,N-dimethylglycine and CXCL4 and thereby suppressing dermal BGN expression (Fig. 5). The study only elucidated the mechanism by which RT counteracts age-associated skin thinning, while the other mechanisms of AT- and RT-driven skin rejuvenation remain to be elucidated.

Both types are valuable

The main finding of this study is that both types of exercise are necessary to maximize the positive effect on skin health. However, that’s not the only reason to integrate both aerobic and resistance training into a routine. The former is significantly better at maintaining a healthy weight and metabolism, while the latter is known to help maintain muscle mass, which is crucial for lasting health.

Literature

[1] Nishikori, S., Yasuda, J., Murata, K., Takegaki, J., Harada, Y., Shirai, Y., and Fujita, S. (2023). Resistance training rejuvenates aging skin by reducing circulating inflammatory factors and improving dermal extracellular matrices. Scientific Reports, 13(1), 10214.

[2] Crane, JD, MacNeil, LG, Lally, JS, Ford, RJ, Bujak, AL, Brar, IK, … & Tarnopolsky, MA (2015). Exercise-stimulated interleukin-15 is controlled by AMPK and regulates metabolism and skin aging. Aging Cell, 14(4), 625-634. Chicago

[3] Corsi, A., Xu, T., Chen, XD, Boyde, A., Liang, J., Mankani, M., … & Young, M.F. (2002). The phenotypic effects of biglycan deficiency are related to collagen fibril abnormalities, are synergized by decorin deficiency, and mimic Ehlers-Danlos-like changes in bone and other connective tissues. Journal of Bone and Mineral Research, 17(7), 1180-1189.