Washington: Here's another reason why you should hit the gym - it can boost your memory.
An intense workout of as little as 20 minutes can enhance episodic memory, also known as long-term memory for previous events, by about 10 per cent in healthy young adults, a new study has found.
The study is not the first to find that exercise can improve memory but it took a few new approaches, researchers said. While many existing studies have demonstrated that months of aerobic exercises such as running can improve memory, the current study by Georgia Institute of Technology had participants lift weights just once two days before testing them.
The researchers also had participants study events just before the exercise rather than after workout. They did this because of extensive animal research suggesting that the period after learning (or consolidation) is when the arousal or stress caused by exercise is most likely to benefit memory.
The study began with everyone looking at a series of 90 photos on a computer screen. The images were evenly split between positive (kids on a waterslide), negative (mutilated bodies) and neutral (clocks) pictures.
Participants weren't asked to try and remember the photos. Everyone then sat at a leg extension resistance exercise machine. Half of them extended and contracted each leg at their personal maximum effort 50 times.
The control group simply sat in the chair and allowed the machine and the experimenter to move their legs. Throughout the process, each participant's blood pressure and heart rate were monitored. Every person also contributed saliva samples so the team could detect levels of neurotransmitter markers linked to stress.
The participants returned to the lab 48 hours later and saw a series of 180 pictures - the 90 originals were mixed in with 90 new photos. The control group recalled about 50 percent of the photos from the first session. Those who exercised remembered about 60 per cent.
"Our study indicates that people don't have to dedicate large amounts of time to give their brain a boost," said Lisa Weinberg, the Georgia Tech graduate student who led the project.
Although the study used weight exercises, Weinberg noted that resistance activities such as squats or knee bends would likely produce the same results. While all participants remembered the positive and negative images better than the neutral images, this pattern was greatest in the exercise participants, who showed the highest physiological responses, researchers said. The study was published in the journal Acta Psychologica.