We look at the claims behind a traditional Chinese medicine in our round-up of this week’s fitness news.
A traditional Chinese medicine called Danggui Buxue Tang (DBT) was recently claimed in a scientific study to effectively cut times in a running time trial by a whopping 14%. It was over 13km, so for comparison purposes, that would be the equivalent of a 50-minute 10km runner dropping their time to 43 minutes.
That’s the headline statement anyway. Before you rush online to buy some, the detail is a little more complicated. In short, it’s unlikely to have that effect on trained runners, but the study perhaps shows the importance of adequate recovery and that this supplement could help if you’re over-training.
Thirty-six “recreationally active” males took part in the study and researchers said the data suggested 11-day supplementation of DBT resulted in a 12-minute reduction in 13km time. However, rather than have the individuals run a time trial before and afterwards, scientists “pair-matched” the participants according to VO2 max. It was claimed the study showed a good correlation between VO2 max and running time trial ability but, as most of us know, it cannot be that accurate. For a start, the runners among them would naturally be quicker at running than the cyclists with the same VO2 max.
DBT has previously been linked to maintaining iron levels in the body so any possible benefits are likely to be due to that. Those that supplemented with DBT showed significantly higher levels of iron post-exercise.
“Short-term DBT supplementation shortened the 13-km running time and repressed exercise-induced hepcidin levels, thereby boosting iron levels and accelerating iron homeostasis during the recovery phase,” wrote the authors.
A 14% improvement in running time claim is perhaps unprecedented, but more research is surely required.
The authors of the study admitted a limitation in that the sample size was very small.
Elsewhere in science news this week:
Men and women differ in the heat
Men and women respond differently when training in the heat, scientists at the University of Buffalo found. Female participants wanted more cooling than the males in the study. It is suggested this could lead to changes in the development of sports clothing in years to come. The article theorises: “Women have more subcutaneous fat than men, and women tend to have greater perceptual responses to temperature changes.” The study also found women’s temperature returned to normal more quickly than men after exercise.
Exercise reduces stress in caregivers
Recent research found that family caregivers who exercised three times per week saw their stress levels reduced. It also beneficially changed a chromosome linked to slowing ageing.
"I am hoping that a new focus on the family caregiver will emerge out of this research," said Eli Puterman from the University of British Columbia, the lead author of the study. "We need to design interventions that help caregivers take care of their bodies and their minds, and provide the type of support that's needed to maintain that long-term.
Downhill better for metabolism
Running downhill led to a greater improvement in metabolism than running uphill or on the flat, in this study by scientists at the University of Isfahan.
But not so for your knees
Downhill running puts greatest stress on a particular joint in the knee than uphill running, scientists at the University of Nevada find. More.
Cushioned shoes increase contact time
A recent study by scientists in Spain analysed five different pairs of running shoes and found ground contact times increase with cushioned shoes versus barefoot.