Step Rate Thresholds Associated with Moderate and Vigorous Physical Activity in Adults.

Adults are recommended to engage in 150 min of moderate (MPA) to vigorous (VPA) aerobic physical activity per week, with the public health message of obtaining 3000 steps in 30 min. There is a paucity of research on step rate thresholds that correspond to absolute MVPA (moderate = 3 METs, vigorous = 6 METs) with no research evaluating adult relative MVPA (moderate = 40% VO2max, vigorous = 60% VO2max). Anthropometric differences also influence intensity-related step rate thresholds. The purpose of this study was to identify step rates across a range of walking intensities so that mathematical models incorporating anthropometric factors could be used to identify individualized MVPA step rate thresholds. Forty-three adults (25♀; age = 39.4 ± 15.2 years) completed a staged treadmill walking protocol with pedometers and indirect calorimetry: six-minutes at 2.4, 3.2, 4.0, 5.6, 6.4, 7.2 km/h. Mathematical modelling revealed absolute and relative MPA step rate thresholds of ~100 steps/minute (spm) and ~125 spm, respectively. VPA corresponded to step rates of ~133 spm and ~139 spm for absolute and relative thresholds respectively. The current public message of 3000 steps in 30 min is valid for absolute MPA. However, VPA is achieved at higher thresholds than previously reported, more than 130 spm for healthy adults.

Influence of Anthropometrics on Step-Rate Thresholds for Moderate and Vigorous Physical Activity in Older Adults: Scientific Modeling Study.

BACKGROUND: Adults and older adults are recommended to engage in 150 minutes of moderate (MPA) to vigorous (VPA) aerobic physical activity (MVPA) per week, with the heuristic message of 3000 steps in 30 minutes (100 steps per minute [spm]). However, this message is based on adult populations, with a paucity of research on step-rate thresholds that correspond to absolute MVPA (moderate=3 metabolic equivalents [METs], vigorous=6 METs) and relative MVPA (moderate=40% estimated METmax, vigorous=60% estimated METmax) in older persons, who have lower stride lengths and a lower exercise capacity. Also, there is a need to consider the influence of anthropometric differences when quantifying the relationship between step rate and intensity-related physical activity. OBJECTIVE: This study assessed absolute and relative MVPA step-rate thresholds and anthropometric factors (ie, height, leg length, and body mass index [BMI]) in older adults. METHODS: Nineteen older adults (7 females; age 69 years, SD 2, BMI 26 kg/m2, SD 4) completed a staged treadmill walking protocol: six minutes at 2.4, 3.2, 4.0, 5.6, and 6.4 km/h. Steps were manually counted and volume rate of oxygen consumed (VO2) was measured via indirect calorimetry. Aerobic fitness was estimated via the submaximal single-stage treadmill protocol. RESULTS: When BMI was considered, mixed effects modeling revealed absolute and relative MPA step-rate thresholds of 108 spm and 117 spm, respectively. Absolute and relative VPA corresponded to step rates of 135 spm and 132 spm, respectively. Neither height nor leg length improved the ability of the model to predict stepping cadence from METs. CONCLUSIONS: In general, older adults need to walk faster than 100 spm (ie, approximately 110 spm) to reach MPA and in excess of approximately 130 spm to achieve VPA, depending on BMI status. Health care professionals and researchers should adjust cadence-based recommendations for differences in BMI in their older patients and consider using relative intensity to most appropriately tailor their physical activity recommendations.

Safe or out: Does the location of attention affect judgments at first base in baseball?

Titchener's law of prior entry states that attended stimuli are perceived before unattended stimuli. Prior entry effects measured with visual stimuli have been generated with both endogenous and exogenous attentional deployment (e.g., by Shore, Spence, & Klein, 2001). In theory, the endogenous form of prior entry may have implications for baseball umpire judgments. Conventionally, umpires are instructed to first attend to the ball when it is hit into play; however, where they attend at the imperative instant of the play at first base can vary between individuals and across scenarios. If the law of prior entry holds in the baseball context, umpires may be biased to make judgments in favour of the imperative event nearest the locus of attention. We tested this hypothesis by having non-umpires make "Safe" or "Out" judgments in response to first base baseball plays wherein the relative arrival times of the runner and baseball were varied. A novel colour wheel method was implemented in an orthogonal task to bias attention endogenously and to measure the effectiveness of this manipulation. Attention was confirmed to be successfully biased to the glove or base by way of improved identification at the likely probe location. However, there was no evidence that prior entry was affecting Safe or Out judgments. (PsycINFO Database Record

Further evidence in favor of prior entry from endogenous attention to a location in space.

Titchener's (1908) law of prior entry states that "the object of attention comes to consciousness more quickly than the objects which we are not attending to," or otherwise, that attended stimuli are perceived earlier than unattended stimuli. Shore, Spence, and Klein (Psychological Science, 12, 205-212. doi: 10.1111/1467-9280.00337 , 2001) showed that endogenous visuospatial orienting does in fact elicit prior-entry effects, albeit to a smaller degree than does exogenous visuospatial orienting. In disagreement with this finding, Schneider and Bavelier (Cognitive Psychology, 47, 333-366. doi: 10.1016/S0010-0285(03)00035-5 , 2003) found no effect of their instruction to attend. They concluded that nonattentional effects could masquerade as prior entry, which could account for findings such as those in Shore et al.'s endogenous condition. We investigated this empirical and theoretical discord by replicating the temporal-order judgment task used by Shore, Spence, and Klein, while manipulating and measuring endogenous orienting by way of an orthogonal color probe task. We showed evidence of prior entry as a consequence of endogenous orienting, supporting the conclusions of Shore, Spence, and Klein.