@Mark and Jonathon:
For example,
+ art. stiffness by RT:
Aerobic, resistance and combined exercise training on arterial stiffness in normotensive and hypertensive adults: A review. - PubMed - NCBI
Relationship between muscle sympathetic nerve activity and aortic wave reflection characteristics in aerobic- and resistance-trained subjects. - PubMed - NCBI cross-sect
Arterial Stiffness and Autonomic Modulation After Free-Weight Resistance Exercises in Resistance Trained Individuals. - PubMed - NCBI short-term longit.
no change:
The effects of resistance exercise training on arterial stiffness in metabolic syndrome. - PubMed - NCBI
RT+ aerobic almost as beneficial as AT alone in AS:
Effect of combined aerobic and resistance training versus aerobic training on arterial stiffness. - PubMed - NCBI
Note there is also mixed evidence with a few studies reporting less arterial stiffness (AS) with RT. However, that mostly seems to be confounded with weight loss, aerobic exercise, and the kind of RT training done in those studies. As higher intensity RT (often defined as >75 or 80%1RM) increased AS whereas lower intensity RT may decrease it. Aerobic, resistance and combined exercise training on arterial stiffness in normotensive and hypertensive adults: A review. - PubMed - NCBI
The positive effects of aerobic exercise on AS are well-established and dont need to be demonstrated.
The effects of AS on outcome markers of health are also pretty clear. I am not aware of a particular longit. RTC of strength trainees, arterial stiffness and outcomes of health. For obvious reasons I dont think there will be any, either. That leaves us with the effects of RT on AS and the effects of AS on health outcomes in general. I dont see much difference in the latter relationship in a RT vs an aerobic trained, other sports trained or sedentary any other population. Save, of course, that other health factors always are at play when finally determining health outcomes, and sure youre better off being not obese and active. So RT may be favorable on AS when in the course of it you become less obese - but thats set apart from the discussion on RT or aerobic exercise on AE itself.
From what I understand its partly the heightened activity of the Sympathetic nervous system triggered by repeated RT (less n. vagus activity) that is responsible for chronic increases in arterial stiffness. One study that investigated cycled vs continued RT suggests that mechanism: https://www.ncbi.nlm.nih.gov/pubmed/25734911 But certainly a cardiologist can explain that better than I can.
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@ stef: Yeah, the good ole man with the cigar. :)
Obviously, there is too little aerobic exercise for some people. Quite what you meant with "people who are moderately active" - the seem to be becoming less and less. I dont think we should be overly surprised about that when a good portion of the population in industrialized countries get up in the morning, get in the car, drive to work, sit there for 8hrs+, drive home, sit in front of the computer/TV for a total of 7hrs sleeping, 16.5hrs sitting and at most 30 out of 1440 minutes per day walking (that I even agree to count as very low intensity aerobic exercise for lack of another term :) ).
You also try bring up the "time constraint" argument. I understand that. "Time is of the essence" for everone nowadays. Well, you cant have everything in no time. If you want to reap the exclusive fruits of RT, you have to do strength training. You cant get the same effects with playing soccer. If you want to have aerobic exercise effects, you have to train that. Same with anaerobic exercise. These effects dont fight each other (save interference effects at higher levels), there is no "better". Plane is no better than car or vice versa. Different behavior have different effects, different advantages and disadvantages. The good thing is that you can do and reap of all these different activities (until high levels of specialization were not talking about when talking about health anyway).
Thats why I strongly think there is a "both and", not "either-or". Yes I know, we all love to fall in this dichotomy of reasons probably better explained by boring psychologists or sociologists. People did in the 80s when aerobic-only was the hype, they did with low-fat diets. No the pendulum has of course swung in the other direction, and even researchers are not unimpressed by fashions. [Of course I have to recommend (if you dont already know him) the godfather of criticizing and educating his own profession here, John Ioannidis. Hes done some very interesting work on analyzing research trends.] One was the savior, the other the devil. The mild form of it: "better vs worse", "high vs low efficiency".
The evidence still supports "both and". Dont (they) tell me you/they dont have time for it because LISS/aerobic exercise can be easliy incorporated in a lot of peopleīs daily life. Just say "I dont like doing X" - I can understand that. I could write exactly the same paragraphs in a runnerīs forum where angry aerobic exercise enthusiasts demand absolute proof that HIIT or RT have certain advantages.
So lets try to avoid falsely rationalizing our personal preferences and dislikes for different activities, methods or sports. Or as Churchill put it: "I am trying to cut down on alcohol. I have knocked off brandy and take Cointreau instead." :)