For young women running on little sleep, 10 minutes of stair walking increased energy more than the amount of caffeine in a soft drink or half a cup of coffee, according to a small study.
This energy boost is relatively short, and overtired workers may need to do a few bouts of exercise throughout the day to keep up energy long term, the researchers are quoted in a Reuters Health report as saying
“There are many people who are sleep deprived and report low energy. We focused on women because they more frequently report low energy compared to men,” said study co-author Patrick O’Connor, a professor of kinesiology at the University of Georgia in Athens, Georgia.
To compare the effects of caffeine and exercise on energy level, the study team recruited 18 female college students with average caffeine intake and physical activity levels. The women in the study were also relatively sleep-deprived, with all reporting sleeping 6.5 hours or less per night.
Before starting the experiment, the women answered questions assessing their feelings of energy or vigour and their motivation levels. The women also completed cognitive tests measuring their attention, short-term memory and reaction times. Participants then received either a flour-filled placebo pill, a caffeine pill containing 50 mg of caffeine (about equivalent to a soda or half a cup of coffee), or completed a 10-minute stair-walking exercise.
After receiving a pill or doing the exercise, the women completed the cognitive tests and questionnaires two more times, 30 minutes and 50 minutes later. The women also rated their feelings of energy a third time, about an hour and 15 minutes after the experiment.
The experiment was repeated two more times over three days, to ensure that each woman experienced each experimental condition.
The researchers found that women who did 10 minutes of stair-walking reported significantly higher levels of energy than women who took the caffeine equivalent of a can of soda. This effect lessened over time, though, and the caffeine and exercise groups had similar energy levels an hour after the experiment.
The interventions did not significantly affect attention, memory, or reaction time.
The effect of exercise in this study was fairly short-lived, O’Connor noted, but other studies suggest that multiple short bouts of exercise spread throughout the workday can offer more long-lasting energy, he said.
A person’s level of fitness may influence what intensity exercise may be helpful for them, said Namrita Kumar, a researcher who studies exercise and attention at the Georgia Institute of Technology in Atlanta. A person with low fitness may be fatigued by intense exercise, which could work against the positive effects they might get from it, noted Kumar, who was not involved in the study.
“For individuals who cannot have or prefer to abstain from caffeine, physical activity throughout the day is sufficient and recommended,” Kumar said. Everyday ways to boost exercise and energy include, “Take the stairs versus the elevator, park in a further parking spot to increase your walking distance, walk or cycle to work or school instead of driving, and take walking breaks,” Kumar said.
“For sleep deprived office workers, especially during inclement weather, taking a 10-minute walk up the stairs can help office workers feel more energetic,” O’Connor said. “Take a break from sitting in your chair and walk up the stairs for a temporary boost in feelings of energy.”
Abstract
Introduction: The acute energizing effect of exercise and caffeine has never been examined in a single study of adults with chronic sleep deprivation but evidence from a study of this type could help individuals choose between these two common alertness-enhancing options.
Aim: The apriori primary aim of this experiment was to compare the influence of 10-min of low-to-moderate intensity stair walking to the consumption of capsules containing 50 mg caffeine or flour (placebo) on feelings of energy in physically active, college female caffeine users with chronic insufficient sleep. Effects on secondary outcomes related to feelings of energy also were assessed.
Material-method: A repeated measures crossover experiment was conducted with 18 college women (18–23 years) who reported (i) daily caffeine consumption that was not extreme (40–400 mg), (ii) typical leisure time physical activity that was not extreme (at least 2 weekly mild 15-min or longer bouts and no > 5 strenuous 15-min or longer bouts), and (iii) sleeping < 45 h per week. Mood states (POMS-BF), focused on energy feelings (vigor), as well as working memory (N-back), sustained attention (CPT), simple reaction time (SRT), and motivation to complete the cognitive tasks were measured before and after a 10-min exercise condition (20 min seated rest followed by 10 min of low-to-moderate intensity stair walking) and compared to both a caffeine condition (50 mg caffeine capsule followed by 30 min of seated rest) and a similar flour (placebo) capsule condition. Condition (exercise, caffeine, placebo) × Time (Baseline, Post-1, Post-2, and for mood Post-3) ANCOVAs (controlling for Condition order) tested the hypothesized effects.
Results: Condition × Time interactions showed that stair walking increased POMS-BF vigor at Post-1 compared to both placebo and caffeine. Other interactions were not significant.
Conclusion: A brief bout of low-to-moderate intensity stair walking has transient energizing effects that exceed a low dose of caffeine for active young women with chronic insufficient sleep.
Authors
Derek D Randolph, Patrick J O'Connor
[link url="http://www.reuters.com/article/us-health-energy-fitness-caffeine-idUSKBN17T36K"]Reuters Health[/link]
[link url="http://www.sciencedirect.com/science/article/pii/S0031938416310666"]Physiology and Behaviour abstract[/link]