BackgroundToday’s cell phones increase opportunities for activities traditionally defined as sedentary behaviors (e.g., surfing the internet, playing video games). People who participate in large amounts of sedentary behaviors, relative to those who do not, tend to be less physically active, less physically fit, and at greater risk for health problems. However, cell phone use does not have to be a sedentary behavior as these devices are portable. It can occur while standing or during mild-to-moderate intensity physical activity. Thus, the relationship between cell phone use, physical and sedentary activity, and physical fitness is unclear. The purpose of this study was to investigate these relationships among a sample of healthy college students.MethodsParticipants were first interviewed about their physical activity behavior and cell phone use. Then body composition was assessed and the validated self-efficacy survey for exercise behaviors completed. This was followed by a progressive exercise test on a treadmill to exhaustion. Peak oxygen consumption (VO2 peak) during exercise was used to measure cardiorespiratory fitness. Hierarchical regression was used to assess the relationship between cell phone use and cardiorespiratory fitness after controlling for sex, self-efficacy, and percent body fat. Interview data was transcribed, coded, and Chi-square analysis was used to compare the responses of low and high frequency cell phone users.ResultsCell phone use was significantly (p = 0.047) and negatively (β = −0.25) related to cardio respiratory fitness independent of sex, self-efficacy, and percent fat which were also significant predictors (p < 0.05). Interview data offered several possible explanations for this relationship. First, high frequency users were more likely than low frequency users to report forgoing opportunities for physical activity in order to use their cell phones for sedentary behaviors. Second, low frequency users were more likely to report being connected to active peer groups through their cell phones and to cite this as a motivation for physical activity. Third, high levels of cell phone use indicated a broader pattern of sedentary behaviors apart from cell phone use, such as watching television.ConclusionCell phone use, like traditional sedentary behaviors, may disrupt physical activity and reduce cardiorespiratory fitness.

The presence of a friend contributes to increased physical activity behavior in young children.

This study used a within-subjects design to assess the effect of three common cellular telephone (cell phone) functions (texting, talking, listening to music) on planned exercise. Forty-four young adults (n = 33 females, 21.8 ± 1.3 years) each participated in four, separate, 30-minute exercise conditions on a treadmill in a random order. During each condition, the treadmill speed display was covered and grade was fixed at zero. However, participants were able to alter treadmill speed as desired. Throughout the texting and talking conditions, research personnel used a pre-determined script to simulate cell phone conversations. During the music condition, participants used their cell phone to listen to music of their choice. Finally, participants completed a control condition with no cell phone access. For each condition, average treadmill speed, heart rate and liking (via visual analog scale) were assessed. Treadmill speed (3.4 ± 1.3 miles∙hour-1), heart rate (122.3 ± 24.3 beats∙min-1) and liking (7.5 ± 1.5 cm) in the music condition were significantly (p ≤ 0.014) greater than all other conditions. Treadmill speed in the control condition (3.1 ± 1.2 miles∙hour-1) was significantly (p = 0.04) greater than both texting and talking (2.8 ± 1.1 miles∙hour-1 each). Heart rate during the control condition (115.4 ± 22.8 beats∙min-1) was significantly (p = 0.04) greater than texting (109.9 ± 16.4 beats∙min-1) but not talking (112.6 ± 16.1 beats∙min-1). Finally, liking during the talking condition (5.4 ± 2.2 cm) was greater (p = 0.05) than the control (4.3 ± 2.2 cm) but not the texting (5.1 ± 2.2 cm) conditions. In conclusion, using a cell phone for listening to music can increase the intensity (speed and heart rate) and liking of a bout of treadmill exercise. However, other common cell phone uses (texting and talking) can interfere with treadmill exercise and reduce intensity.

Sanders, GJ, Boos, B, Rhodes, J, Kollock, RO, and Peacock, CA. Competition-based heart rate, training load, and time played above 85% peak heart rate in NCAA division I women's basketball. J Strength Cond Res 35(4): 1095–1102, 2021—Basketball athletes frequently engage in intensities ≥85% HRpeak throughout competition. Knowing the time spent competing at intensities ≥85% HRpeak can improve training protocols. The purpose of the study was to assess heart rate responses across 4-quarter games (N = 31) in an NCAA Division I women's basketball season. Ten female athletes were tested and monitored with heart rate–based wearable microsensor devices. Before the season, HRpeak was recorded through a peak metabolic test (V̇o 2peak). Average (HRavg) and HRpeak were recorded for each game, and time spent in 5 heart rate zones (HRZones) were recorded: HRZone1 = 50–60% HRpeak, HRZone2 = 60–70% HRpeak, HRZone3 = 70–76% HRpeak, HRZone4 = 77–84% HRpeak, and HRZone5 = 85–100% HRpeak. Training load was calculated with the summated-heart-rate-zone model (SHRZmod). There was a main effect of position (p ≤ 0.019) and quarter (p ≤ 0.005) on SHRZmod and on time spent in HRZone1–5. Athletes accumulated the most time in HRZone4 and HRZone5 and in the fourth quarter, and SHRZmod was the greatest in the fourth quarter. There was no main effect for HRavg and HRpeak (p ≥ 0.110). Athletes averaged 34.5 minutes per game competing in HRZone5 or ≥85% HRpeak with nearly one-third of those minutes accumulated in the fourth quarter. Although there were no differences in HRavg and HRpeak from quarter to quarter, SHRZmod increased from the first to fourth quarter. Utilizing time spent in heart rate zones and training load with SHRZmod can provide valuable information to practitioners regarding the intensity and physiological demands of competitive basketball games.