The subjects were divided into four groups. 1. no exercise, 2. aerobic exercise only 3. Resistance (strength training) exercise only, or 4. aerobic plus resistance exercise.  The exercising groups engaged in a supervised workout for one hour, three times per week for one year.

Each subject received a specific workout routine matched to their individual fitness level, and their health conditions. For aerobic exercise, participants wore a heart rate monitor during the exercise routine, and the intensity of the workout was adjusted in conjunction with heart rate. For resistance training the participants were assigned the amount of weight to lift and the number of repetitions and sets to be done. Researchers recorded important health data from the participants at the beginning of the year study, after six months and at the end of the year long study. They measured fasting glucose, LDL cholesterol (“bad cholesterol” ), systolic blood pressure and body fat percentage. These are all very well documented  cardiovascular disease risk factors.

During the year-long trial the subjects met with a registered dietician every three months. They were schooled in the NIH published guide called “Dietary Approaches to Stop Hypertension”. https://www.ncbi.nlm.nih.gov/books/NBK482514/#:~:text=What%20does%20this%20diet%20include,minimally%20processed%20and%20fresh%20food.

Also,on three days per month, the subjects were told to record what they had consumed in the prior 24 hours to assess how much their dietary intake conformed to the recommendations.

Study Results

At the end of the year-long trial, the percentage of body fat in all three exercise groups had decreased significantly compared to the no-exercise control group. The authors write in the paper that “every -1% body fat reduction is associated with -3% reduction in hypertension, -4% reduction of hypercholesterolemia and an 8% lower risk of metabolic syndrome.”

Taking into account all four cardiovascular disease risk factors, they found that the combined aerobic and strength training  exercise groups had the best outcomes. The results were consistent across gender, age and ethnicity.

Other findings

Over the course of the 1 year study, those in the aerobic-only group continued to improve their  maximum rate of oxygen consumption (Vo2) attained via a maximal treadmill test. This did not improve in the resistance-only group. The combination exercise group improved in both muscle strength and  aerobic fitness, and saw the most overall health benefit.

What Amount of Exercise is Needed ?  Physical activity guidelines have been  recommended for both resistance and aerobic exercise by the U.S., World Health Organization, and European Society of Cardiology. They recommend at least 150 minutes each week of moderate intensity aerobic exercise and two sessions per week of resistance training.

“But these guidelines don’t specify how long those strength training sessions should be to get the health benefits,” says lead researcher Dr. Lee who intends to find  “the right dose” of resistance exercise among adults who are overweight or obese. He is planning another study this time with 240 subjects participants. They intend to compare the  results from 15 minute,  30 minute  and 60 minute resistance sessions, twice per week over 6 months supervised in the lab. All study subjects will  also be tasked to do half hour sessions of moderate intensity aerobic exercise, twice per week. Data from these subjects will be reported for the new study.

An NIH review of RESISTANCE TRAINING

The National Institutes of Health published the National Physical Activity Guidelines: Resistance training (RT) is advised which encompasses working all major muscle groups at least twice  per week. Elderly people have been shown to gain muscle strength and muscle mass. Resistance training also maintains bone density, slowing the development of osteoporosis . Indeed, resistance training may impart even greater benefits to the elderly  population than to others, countering a variety of health problems affecting older adults. The elderly are at greater risk of premature death due to falls, which are associated with the age-related decline seen in muscle strength and balance.2–5   The Centers for Disease Control (CDC) say that 25% of adults over 65+ years of age suffer a significant fall yearly.6

Other than the improvement in muscle strength there are a number of other  health measurements and conditions that have been shown to improve in older Americans who engage in resistance training.7

Studies have shown the following benefits:

bone mineral density,8,9 

lipoprotein profiles,10 

glycemic control,11 

body composition,12 

symptoms of frailty,13 

metabolic syndrome risk factors,14 

and cardiovascular disease markers.15 

Also studies have  shown that Resistance Training  decreases  the risk of “all-cause mortality” (dying of any cause) 16,17 18 . 

Along with the physical changes outlined above there are improvements in mental health that have been observed after resistance training such as perceived stress,20 depression,21 anxiety,22 and fatigue.23 Also what one study called “sense of coherence”,19 improves.

The benefits of aerobic exercise have been quite extensively studied. This  research provides evidence that both aerobic and resistance training together is superior to just doing aerobic exercise alone.