Facilitating participation in health-enhancing physical activity: a qualitative study of parkrun

Background Public health guidelines emphasise the value of vigorous intensity physical activity, but participation levels are low. Purpose This study was aimed at identifying factors contributing to initial and sustained engagement in parkrun in the UK, to inform the design of community-based interventions promoting health-enhancing physical activity. Methods Semi-structured interviews were conducted by telephone with 48 adult participants of parkrun, a national network of weekly, free, volunteer-led, timed 5 km runs in public spaces. The framework approach was used for thematic analysis of transcripts. Results Two overarching themes emerged: freedom and reciprocity. Freedom referred to the accessibility and inclusivity of events, both of which contributed to initial attendance and sustained involvement. Reciprocity related to the dual opportunity for personal gain and for helping others. Anticipation of fitness and health benefits were important for initial motivation. However, additional aspects motivating continued involvement included achievement of time or attendance goals, social cohesion, and contributing to the community. Conclusions Specific features of the parkrun experience encouraged participation including the accessible, inclusive ethos, achievement opportunities, and inherent social support, along with the outdoor natural settings, and integrated volunteer system. The inclusion of these elements in community-based interventions may increase success in initiating and maintaining health-enhancing physical activity

Demographics and personal HAIR calculations for the 50 dietary study participants.

<p>General, dietary intake and nosebleed demographics and derivatives, calculated from the FFQ (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone.0076516.s001" target="_blank">Table S1</a>) and raw data for nosebleeds (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone-0076516-g002" target="_blank">Figure 2</a>). RDA, recommended dietary allowance (8 mg for males and post-menopausal females, 18 mg for non pregnant pre-menopausal females); 95% CI, 95% confidence intervals; ESS, epistaxis severity score, where number refers to ESS question number. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone.0076516-Hoag1" target="_blank">[50]</a> *The final ESS score ranges from 0–10, where a higher score equates to greater blood losses. Dietary iron intake was no higher in pre-menopausal females (Kruskal Wallis <i>p</i> value 0.22), none of the pre-menopausal females achieved their recommended iron intake, and the difference in the proportion of pre-menopausal females and males/postmenopausal females meeting their RDA was statistically significant (p<0.001, Mann Whitney). Male gender weakly correlated with a higher dietary iron intake, but once corrected for gender, individuals with longer nosebleeds tended to have higher dietary iron intakes (data not shown).</p

Iron intakes from diet and iron supplements.

<p>The nine individuals using ferrous sulphate, ferrous gluconate, ferrous fumarate or other iron supplements, are illustrated with pairwise comparisons of their dietary iron intake from the FFQ (left red bar) and dietary FFQ intake plus their supplement iron intake (right red bar) in addition to each individual’s log(RDA) and personalised log(HAIR), which were calculated according to their personalised iron losses and RDA for iron. As in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone-0076516-g001" target="_blank">Figure 1</a>, note that generally short (0.5–2.5 min) nosebleeds less than once per month resulted in log(HAIR) of approximately 2; several nosebleeds per week of 5 minutes or more in a log(HAIR) of ∼3; daily 10 min nosebleeds a log(HAIR) of ∼4, and several nosebleeds per day, each lasting 2.5–10 minutes, in a log(HAIR) of 5. The two highest intakes were seen in individuals using ferrous sulphate 325 mg bd; the next six in users of once daily ferrous sulphate or ferrous fumarate.</p

Relationships between hepcidin and iron indices.

<p><b>A and B)</b> Hepcidin levels according to approximate tertile groupings of <b>A)</b> serum iron, and <b>B)</b> serum ferritin. Note that the reference range for hepcidin using this radioimmunoassay is 1.1–55 ng/mL. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone.0076516-Busbridge1" target="_blank">[58]</a> Details of individual participants are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone-0076516-t004" target="_blank">Table 4</a>. <b>C)</b> and <b>D)</b> Best fit quadratic regression relationships (with shaded areas indicating the 95% confidence intervals) for hepcidin with <b>C)</b> serum iron, and <b>D)</b> ferritin.</p

Details of the nosebleeds reported by the online survey respondents.

<p><b>A)</b> Reported volume (mls) of individual nosebleeds, converted where appropriate from original units of measurement to mls as described in the methods. <b>B)</b> Reported duration (minutes) of individual nosebleeds. Corroborating evidence for specified major bleeds was provided by 16 individuals, and included acute hemodynamic consequences (faints, collapses, n = 5); hematocrit/hemoglobin falls (n = 4 including 3.2 g/dl hemoglobin fall in 8 hours; 8 units of hematocrit over 3 days); and unspecified acute transfusions or hospital admission (n = 8). There was no corroboratory evidence for the two indicated outliers (red crosses) whose values were excluded from calculations for the median, 20^th and 5^th percentile values used in nosebleed rate conversions<b>.</b></p

Stratification of blood hematinic and iron indices according to HAIR values and iron supplement use.

<p><b>A–E:</b> Distributions of all participants, either by conventional recommended dietary allowance (RDA, left two box plots (mens., menses distinguishing males and post menopausal women from pre-menopausal women), or by approximate quintile (Qu) determined by HAIR (right five box plots, exact figures provided in methods). <b>A)</b> HAIR values (mg of iron per day). <b>B)</b> Serum iron (µmol/L). <b>C)</b> Hemoglobin (Hb, g/dL)). <b>D)</b> Mean corpuscular hemoglobin concentration (MCHC, g/dl). <b>E)</b> Red cell distribution width (RDW). <b>F)</b> Quadratic regression plots for the distribution of hemoglobin according to HAIR, in study participants using oral iron supplements (continuous line with 95% confidence interval indicated), and those who did not (dotted line).</p

Multivariate logistic regression of the risk of persistent anemia, if using iron tablets.

<p>The final model presenting all variables making a significant contribution to the risk of persistent anemia, once adjusted for the presence of other variables, in HHT online survey respondents using iron tablets. The model details 424 observations providing a pseudo r² of 0.14, and overall model <i>p</i> value of <0.0001. P values were calculated post estimation, both by likelihood ratio (LR) tests which assume independence of observations within a cluster (an assumption that was not met with these data), and the non parametric Wald test which does not make such assumptions. There was no clear relationship between persistent anemia and iron tablet-induced nausea, constipation, or abdominal pain (likelihood ratio test <i>p</i> values 0.14, 0.11, and 0.09 respectively). There was also no relationship with age, gender, other otorhinolaryngologic treatments <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone.0076516-Silva1" target="_blank">[37]</a> either combined or individually, or other reported HHT treatments for pulmonary, cerebral or hepatic arteriovenous malformations (data not shown).</p

Multiple regression of log transformed (ln) hepcidin.

<p><b>A)</b> Model using ferritin alone. 95% CI, 95% confidence intervals. Overall model parameters: sum of squares 17.2; 20 degrees of freedom; mean square 0.86; variance ratio (F) 11.0; adjusted r² = 60.0; overall p value for model = 0.0001. <b>B)</b> The final model for ln(hepcidin), generated by stepwise multiple regression in data from 21 HHT patients. Overall model parameters: sum of squares 17.2, 20 degrees of freedom, mean square 0.86, variance ratio (F) 81.5, adjusted r² = 92.4, overall p value for model <0.0001. No other captured variable contributed to the model.</p

Quadratic regression of hematinic and iron indices with HAIR.

<p>Age and gender-adjusted HAIR regression coefficients with the designated variable were calculated using the designated variable as the dependent variable (distributional graphs are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076516#pone.0076516.s002" target="_blank">Figure S1</a>) for quadratic regression, and simultaneously examining the relationships with age, gender, and HAIR. MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; ln(RDW), log-transformed red cell distribution width; ln(iron), log-transformed serum iron; ln(T<i>f</i>SI), log-transformed transferrin saturation index; ln(ferritin), log-transformed serum ferritin. 48 datasets were available except for RDW (n = 46), iron and T<i>f</i>SI (n = 45), and ferritin (n = 41). Excluding outliers in the MCV, MCH and MCHC regressions did not materially alter the results (p = 0.76 for MCV, n = 44; p = 0.035 for MCH, n = 43 and p = 0.001 for MCHC, n = 36). Age, gender and iron supplement-adjusted HAIR regression coefficients with the designated variable were calculated by quadratic regression, using the designated variable as the dependent variable, and simultaneously examining the relationships with age, gender, iron supplement use, and HAIR. Iron supplements contributed significantly to the final models of MCHC and ln(RDW), reducing the respective HAIR p values in age, gender and iron supplement adjusted regression.</p

Multivariate linear regression analysis of serum PTH levels.

**<p>p-value for interaction effect.</p><p>R² = 0.515 (Adjusted R² = 0.452).</p><p>Abbreviations: ART, antiretroviral therapy.</p