Research Bites : ACSM's Health & Fitness Journal

Secondary Logo

Journal Logo

Columns: Research Bites

Research Bites

Yoke, Mary Ph.D., FACSM, M.A., M.M.

Author Information
ACSM's Health & Fitness Journal 26(3):p 40-42, 5/6 2022. | DOI: 10.1249/FIT.0000000000000760
  • Free



In a systematic review and meta-analysis published recently, authors Laranjo et al. (1) evaluated 28 studies, published between 2014 and 2019, in order to find out whether apps and activity trackers were effective in promoting physical activity. In other words, are apps and activity trackers useful in getting people to move more? The short answer is — yes!

Readers of this journal are well aware of the importance and numerous benefits of regular physical activity. Thousands of rigorous studies have helped us become knowledgeable about exercise physiology and exercise programming. And we have increasing evidence that any movement really is better than nothing at all in terms of health benefits (2). Yet despite all our knowledge, health/fitness promotional endeavors, and considerable energy, a majority of people in the United States and other developed countries are distressingly sedentary and physically inactive, leading to premature disease, disability, and death. What can be done? What more can we do? In my opinion, it is paramount to understand and implement behavior change techniques; this is the next frontier in health and fitness if we want to impact the general population. As Laranjo et al. pointed out, self-monitoring and immediate and continuous feedback are powerful and effective strategies for helping people change, and activity trackers and apps are well positioned to do just that.

In the Laranjo et al. (1) systematic review, the authors were most interested in measures of physical activity, subsequent to wearing an activity tracker or carrying a smartphone with an activity tracker app. Of particular interest were participants' daily step counts (a proxy for physical activity). Twenty-eight randomized controlled trials met the authors' inclusion criteria, and a total of 7,454 participants were involved. Most of the studies in the review focused on sedentary adults or on overweight/obese adults without chronic disease. The durations of activity tracker/smartphone usage reported in the studies were between 2 and 40 weeks (mean = 13 weeks), and a mean retention rate of 90.5% was reported in the four studies that measured compliance. In addition to activity tracker and app usage (which included self-monitoring), several studies included additional behavior change techniques, such as goal setting, social support, text messaging of prompts and cues, gamification, feedback from others, personalization, and instruction on how to perform the behavior; some studies included motivational interviewing and financial incentives.


After reviewing and analyzing all 28 studies, the authors found that using an activity tracker or an app had a small-to-moderate effect on physical activity after a mean of 13 weeks. Participants had an average increase of 1,850 steps per day compared with controls — a significant improvement.

The authors write that future studies should report engagement measures to explore the dose–response relationship between activity tracker use and increased physical activity. What is meant by engagement? In my own research on activity tracker usage, we parsed the word “usage” (3). We decided that activity tracker usage means that a person must 1) wear the device, 2) look at the device several times per day, and 3) adjust their behavior based on what they see, deciding either to move more or to stay put. Participants who do all three of these behaviors did actually take more steps than those who did none, one, or two of the behaviors. Perhaps this is what Laranjo et al. (1) meant by engagement and/or dose–response.

In any event, the results of the Laranjo et al. (1) systematic review and meta-analysis are good news. An average increase of 1,850 steps per day is a doable behavioral change that can help to improve health and may be extremely beneficial at the population level. Let’s encourage our participants to use those activity trackers and smartphone apps!


Have you heard of forest bathing? Known as shinrin-yoku in Japan, where it is formally practiced and extensively researched, forest bathing is intended to reduce technology burnout and help people relax and reconnect with nature. More and more evidence-based studies are validating forest bathing’s effects and the effects of green spaces on the mind and body. These effects include decreased blood pressure, decreased depression, and increased immune system functioning. Forest bathing is generally defined as mindful walking (paying attention to the senses) while also paying attention to all elements within a forest.


McEwan et al. (4), in their 2021 study, explored the effects of forest bathing and/or compassionate mind training (CMT) on well-being and heart rate variability (HRV) in the United Kingdom. In addition to forest bathing, CMT also was chosen as an independent variable in this study because it likewise targets the body’s parasympathetic nervous system, which is responsible for relaxation, emotional regulation, and the return to homeostasis after a period of stress. Regarding the dependent variables, it is important to note that HRV is considered to be an important marker for overall health. Increased resting HRV can indicate increased parasympathetic nervous system activation and, therefore, an improved ability to tolerate stress.

Sixty-one participants (50 females, 11 males) of mixed ages were divided into one of three groups: forest bathing conducted in semiancient woodland, CMT conducted indoors, or both CMT and forest bathing conducted outdoors in semiancient woodland. Forest bathing sessions were led by qualified instructors and consisted of slow, silent walking through woodland areas; participants were encouraged to focus on all the senses and breathe deeply and slowly. Additionally, forest bathing involved sitting and leaning against a tree and/or lying down under the tree canopy while remaining mindfully aware. On three occasions, participants were subsequently directed to share their experiences with each other in order to gain deeper perspectives about outdoor mindfulness.

CMT sessions were led by qualified instructors and included CMT education and practices using compassionate imagery, receiving compassionate images from others, and providing compassion to oneself. In the combined condition, forest bathing was combined with CMT and compassion for other species and the environment. Measurements included the Profile of Mood States and HRV measures. HRV measurement used ambulatory devices while listening, smelling, practicing compassionate imagery, etc.

What were the findings? Well, there were no significant differences between the three conditions, indicating that forest bathing was as effective as the more well-established practice of CMT. Across all trials, improvements were found in participants' moods (less anger, depression, fatigue, confusion) and in their HRV measures. The authors also wanted to see if HRV changed during specific tasks such as lying down, compassionate imagery, listening to water, sharing time with a tree, etc.; measurements did, in fact, show enhanced HRV during these activities.

We know that every study has some limitations. McEwan et al. (4) mention that some limitations of their study include the high percentage of female participants versus males, the individual time constraints for the forest bathing sessions, and the issue of potential biophobia for seven of the participants (biophobia refers to a fear of certain species, such as snakes or spiders, and/or a general aversion to nature).

Are you excited to include more forest bathing in your life? Current recommendations suggest that you practice mindfully walking and resting in a forest/woodland for 2 to 3 hours at least once every 2 weeks for increased well-being. As the authors point out, forest bathing not only can improve our own physiological and psychological well-being but also can increase our appreciation of and compassion for nature and make it more likely that we will act to protect our natural environments for the foreseeable future.


Listen up, video gamers! In a recent study by DiFrancisco-Donoghue et al. (5), a light-intensity 6-minute walking break after an intense hour-long session of competitive gaming was found to improve executive brain function and processing speed.

Prolonged sitting is endemic among video gamers. Competitive play requires up to 500 keyboard or mouse actions per minute, and gamers often experience a high degree of cognitive stress while playing. Physiologically, the literature shows that there is an increased risk of deep vein thrombosis and other cardiovascular and cerebrovascular risk factors due to excessive sitting while playing video games.

In the DiFrancisco-Donoghue et al. (5) study, 21 experienced, first-person-shooter (FPS), competitive video gamers (12 men and 9 women, mean age of 20.76 years) participated virtually (due to COVID-19 lockdowns in 2020). Measurement occurred on three intermittent days of FPS gameplay, lasting 2 hours and 15 minutes each. On one day, the trial involved continuous gameplay with no break; on another, a 6-minute active-walking break was incorporated with 60 to 75 minutes of gameplay before and after, and on another day, a 6-minute passive supine resting break was provided, with 60 to 75 minutes of gameplay before and after. The three days were randomized among the participants. An investigator stayed in touch with participants via smartphone during all three trials. Participants rated their perceived effort during active game play and during walking using the Borg RPE scale and recorded their numbers of wins, losses, and kill–death ratios for each game. Online executive function tests were administered immediately afterward; these included the color word Stroop test and the Tower of London test.

The walking trial resulted in significantly faster solution and planning times compared with the continuous play trial; the resting condition yielded the slowest times. FPS gameplay is fast paced and complex, demanding quick reaction time, precise hand/eye coordination, and high executive functioning, in addition to high levels of focus, consistency, and stamina. This study demonstrates that 6 minutes of walking during a break may help improve gaming performance as well as health.


1. Laranjo L, Ding D, Heleno B, et al. Do smartphone applications and activity trackers increase physical activity in adults? Systematic review, meta-analysis and metaregression. Br J Sports Med. 2021;55:422–32.
2. Edelund U, Tarp J, Steene-Johannessen J, et al. Dose–response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonized meta-analysis. BMJ. 2019;366:14570.
3. Yoke MM, Middlestadt SE, Lohrmann DK, Chomistek AK, Kennedy-Armbruster CA. The behavior of activity tracker usage in trained users. Med Sci Sports Exerc. 2018;50:5, Supplement.
4. McEwan K, Giles D, Clarke FJ, et al. A pragmatic controlled trial of forest bathing compared with compassionate mind training in the UK: impacts on self-reported wellbeing and heart rate variability. Sustainability. 2021;13:1380.
5. DiFrancisco-Donoghue J, Jenny SE, Douris PC, et al. Breaking up prolonged sitting with a 6 min walk improves executive function in women and men esports players: a randomized trial. BMJ Open SEM. 2021;7:e001118.
Copyright © 2022 by American College of Sports Medicine.