A team of scientists from Taiwan is suggesting not all exercise is equal when it comes to those with a genetic propensity for obesity trying to lose weight. The study concluded jogging was better for weight loss than either swimming or cycling in those subjects with a genetic predisposition for obesity.
The new study looked at data from over 18,000 adults, tracking the interaction between genetics and exercise on five obesity measures. Each subject was given a genetic risk score for obesity, accounting for a large volume of genes previously discovered to be associated with weight-gain and obesity. The efficacy of 18 kinds of exercise wwas investigated using five different obesity measures: body mass index (BMI), body fat percentage (BFP), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR).
Out of all the exercises examined, jogging was the most broadly effective at mitigating the genetic effects of obesity across all five obesity measures. Looking at just BMI, five other exercises stood out as most beneficial in those predisposed to obesity: mountain climbing, walking, exercise walking, international standard dancing, and a long yoga session. On the other hand, several forms of exercise did not seem to modify the genetic effects of obesity. These exercises include swimming, cycling, and general stretching.
Of course, this study is riddled with a number of limitations, not the least of which is that its entire cohort is comprised of Han Chinese individuals, limiting how broadly we can interpret the results to different people around the globe. Another problem is that physical activity was self-reported by participants, with exercise defined as an activity lasting 30 minutes performed at least three times a week. Self-reported measures are notoriously unreliable, and some of the reported exercises, including basketball, tennis and other sports, were too under-represented to generate relevant results.
Nevertheless, the researchers do attempt to hypothesize why some exercises manifest better results than others. It is suggested that jogging, for example, compared to swimming and cycling, generates a higher level of energy expenditure which would result in better results for those genetically predisposed to obesity. Other explanations are not as convincing, such as the hypothesis suggesting swimming is not as effective as other exercises because exposure to cold water stimulates appetite and food intake.
This study is not the first to suggest different kinds of exercise can have different effects. An interesting study last year proposed endurance exercise stimulates anti-aging processes whereas resistance exercise does not. Another intriguing recent study concluded aerobic exercise, as opposed to lower-intensity stretching sessions, can specifically lessen the negative symptoms associated with schizophrenia.
The new research is only focused on certain obesity measures, so it does not imply exercises such as swimming or cycling are not physically beneficial. Instead, what the research is attempting to understand is why some people may not lose as much weight as others from certain types of exercise. While the mechanisms to explain this study's results are still unknown, the most immediate takeaway is the implication individuals try a variety of different exercise strategies to find what works best for one's particular physiology.
The new research was published in the journal PLOS Genetics.
Source: PLOS via ScienceDaily