Strength training gives valuable muscular gains, but doesn’t give the heart health benefits of aerobic exercise, according to research from Iowa State University. The study, Aerobic, resistance, or combined exercise training and cardiovascular risk profile in overweight or obese adults, was published in the European Heart Journal. A one-year randomised control exercise trial, it included 406 participants aged between 35 and 70.

All met the criteria for being overweight or obese; had slightly elevated blood pressure, but weren’t taking medication; were non-smokers and prior to the study were not meeting activity guidelines. The participants were predominantly white and well-educated.

Tailored workouts
Participants were randomly assigned one of four groups: no exercise, aerobic only, resistance only, or aerobic and resistance. The exercise groups worked out for one hour, three times a week, for one year.

Workouts were tailored according to fitness levels and health conditions, with built-in progression. Activity and diet data outside of the laboratory was taken into consideration.

At the start of the trial, half-way through and at the end, the researchers measured a number of health indicators, including blood pressure, low-density lipoprotein cholesterol, fasting glucose and body fat percentage, which are all cardiovascular disease risk factors.

At the end of the trial, the percentage of body fat in all three exercise groups had decreased significantly compared to the no-exercise control group. But taking all four cardiovascular disease risk factors into consideration, the aerobic and combined exercise groups had lower composite scores than the control group.

As expected, those in the aerobics-only group saw the greatest improvements in the VO2 max test and the resistance-only group saw the biggest gains in tests for muscular strength.

Combined exercise wins
However, the combination exercise group saw improvements in both aerobic fitness and muscular strength, suggesting that a 50/50 mix between strength and cardio is the best way to train.

Researcher Duck-chul Lee said: “Our study shows you can replace half your aerobic workout with strength training to get the same benefits.”

Meta-analysis suggests aerobic or combined exercise is generally superior to resistance training in relation to blood pressure, body fat, glucose metabolism and lipid profile.

Observational studies also suggest that combined exercise provides somewhat larger risk reductions in developing clinical endpoints, such as metabolic syndrome, hypercholesterolaemia, obesity and cardiovascular morbidity or mortality.

The lean mass gained with strength training makes it appealing for those looking to improve body aesthetics and those who find cardio exercise difficult.

Although the study was designed to induce no, or negligible, weight loss, the findings of -1 per cent body fat reduction is associated with -3 per cent, -4 per cent and -8 per cent lower risks of developing cardiovascular disease risk factor of hypertension, hypercholesterolaemia and metabolic syndrome respectively.

More: www.news.iastate.edu