Hala Nassif

Improving health through policies that promote active travel: A review of evidence to support integrated health impact assessment

BACKGROUND Substantial policy changes to control obesity, limit chronic disease, and reduce air pollution emissions, including greenhouse gasses, have been recommended. Transportation and planning policies that promote active travel by walking and cycling can contribute to these goals, potentially yielding further co-benefits. Little is known, however, about the interconnections among effects of policies considered, including potential unintended consequences. OBJECTIVES AND METHODS We review available literature regarding health impacts from policies that encourage active travel in the context of developing health impact assessment (HIA) models to help decision-makers propose better solutions for healthy environments. We identify important components of HIA models of modal shifts in active travel in response to transport policies and interventions. RESULTS AND DISCUSSION Policies that increase active travel are likely to generate large individual health benefits through increases in physical activity for active travelers. Smaller, but population-wide benefits could accrue through reductions in air and noise pollution. Depending on conditions of policy implementations, risk tradeoffs are possible for some individuals who shift to active travel and consequently increase inhalation of air pollutants and exposure to traffic injuries. Well-designed policies may enhance health benefits through indirect outcomes such as improved social capital and diet, but these synergies are not sufficiently well understood to allow quantification at this time. CONCLUSION Evaluating impacts of active travel policies is highly complex; however, many associations can be quantified. Identifying health-maximizing policies and conditions requires integrated HIAs.

Athlete atypicity on the edge of human achievement: performances stagnate after the last peak, in 1988.

The growth law for the development of top athletes performances remains unknown in quantifiable sport events. Here we present a growth model for 41351 best performers from 70 track and field (T&F) and swimming events and detail their characteristics over the modern Olympic era. We show that 64% of T&F events no longer improved since 1993, while 47% of swimming events stagnated after 1990, prior to a second progression step starting in 2000. Since then, 100% of swimming events continued to progress. We also provide a measurement of the atypicity for the 3919 best performances (BP) of each year in every event. The secular evolution of this parameter for T&F reveals four peaks; the most recent (1988) followed by a major stagnation. This last peak may correspond to the most recent successful attempt to push forward human physiological limits. No atypicity trend is detected in swimming. The upcoming rarefaction of new records in sport may be delayed by technological innovations, themselves depending upon economical constraints.

Success and Decline: Top 10 Tennis Players Follow a Biphasic Course

INTRODUCTION The victory percentages for tennis players who entered the top 10 women and men rankings show various evolutions related to age and time since 1968. METHODS The study analyzed the careers of all top 10 players: 97 women (50,933 matches) and 144 men (92,450 matches). For each player, we describe a biphasic performance course. Two generations were compared: the first one (G1), including players who started their professional career before 1985, and the second one (G2), with players starting after 1985. RESULTS The average career length is 16.1 ± 3.8 yr for the top 10 men and 15.8 ± 4.4 yr for women. Compared with G1 players, G2 players begin earlier (women = 1.3 yr, men = 0.8 yr), but career length remains the same. An exponential model describes the time course of the victory percentage with a great similarity for both genders. Using this equation, the peak victory rate reaches 82.5% at 21.5 yr for number 1 (no. 1) women and 78.5% at 23.7 yr for no. 1 men, showing a greater precocity and earlier decline in women. Finally, the area under the curve shows a potential that is 22.8% (men) to 56.8% (women) larger for the no. 1 players as compared with all other numbers 2-10. CONCLUSIONS Tennis players in the top 10 show a biphasic career. Women reach their highest level earlier than men, consistent with their more precocious biological development. For the current generation, the peak performance tends toward a younger age than the first generation. We show how to precisely quantify and compare tennis performances using indicators that follow the trends of development and aging and demonstrate that precocity does not provide a larger victory potential.

Technology & swimming: 3 steps beyond physiology

The science of engineering materials and the development of materials science during human history have strongly evolved over the past two centuries 1,2. Other new technological fields such as particle physics, computer science, nanoscience also flourished 3 , all leading to innovations that impacted sport. Polymers and metal alloys such as carbon fibres are exemplars of materials now widely used in various disciplines 4. In 2008, polyurethane made its first appearance in swimming with the use of a new swimsuit generation. The result was a sudden improvement of performances, allowing athletes to go beyond physiological limits that have been nearly reached 5,6. This study aimed to quantify the gain provided by the three generations of swimsuits introduced in 1999, 2008, 2009 and to estimate the upcoming performance drop in 2010. Using a recently published methodology 7 , we analyzed the single best result each year for the worlds top ten swimmers from 1990 to 2009 in order to assess the sudden progression trends and quantify the total performance gain. Materials and methods We collected the best performance of the worlds top ten swimmers every year in 34 swimming events from 1963 to 2009 8-10. A total of 6790 individual performances were selected from the data spanning the 1990 – 2009 period as they present a complete measure each year. We focus here on the impact of material science in swimming by measuring the impact of the three successive generations of swimsuits on human performance and estimate the upcoming performance drop consecutive to the decision of the FINA to suspend their use. We investigate the recent evolutions of the best performers over the 1990 – 2009 period and demonstrate that three bursts of performances occurred in 2000, 2008 and 2009. The overall observed gains of these bursts exceed 2.0% for both sexes. The drop in performance that may result from this rule change may return to similar levels as seen in 1999.

Evaluation of a Randomized Controlled Trial in the Management of Chronic Lower Back Pain in a French Automotive Industry: An Observational Study

OBJECTIVE To evaluate a specific workplace intervention for the management of chronic lower back pain among employees working in assembly positions in the automotive industry. DESIGN Randomized controlled trial. SETTING On site at the workplace of a French automotive manufacturer. PARTICIPANTS Subjects (N=75 volunteers) were recruited on site and randomly assigned to either an experimental group (n=37) or a control group (n=38). INTERVENTION The experimental group followed a supervised 60-minute session, 3 times per week, of muscle strengthening, flexibility, and endurance training during 2 months. The control group received no direct intervention. Evaluation took place at baseline, 2 months, and 6 months. MAIN OUTCOME MEASURES Pain related parameters were evaluated using validated questionnaires and scales translated into French (Quebec Back Pain Disability Scale, Rolan Morris Disability Questionnaire, Dallas Pain Questionnaire, and the Tampa Scale for Kinesiophobia). Perceived pain intensity was evaluated using the numerical rating scale, and physical outcome measures were evaluated using specific indicators (flexibility, Biering-Sorensen Test, Shirado test). The multivariate analysis of variance, t test, and Wilcoxon signed-rank test were used for statistical analysis. RESULTS We observed a significant beneficial effect (P<.025) for the experimental group at 2 and 6 months in pain parameters, specific flexibility, and in back functions, and a significant improvement at 6 months in the control group for the perceived pain intensity, anterior flexion, flexibility of quadriceps, and Dallas Pain Questionnaires work recreational score. An increase in the practice of physical activity outside the workplace was noted in both groups at 2 months but persisted at 6 months for the experimental group. CONCLUSIONS This study reinforces the multiple health benefits of physical activity and physical therapy modalities in the workplace by assisting individuals at risk who have chronic LBP.

Monitoring fitness levels and detecting implications for health in a French population: an observational study

Objective To analyse the physical fitness of a large sample of the French population across different ages. Design Observational cross-sectional study. Setting Data were collected from the Athletic Track and Field Federation, which organised events dedicated to measuring physical fitness. The events took place in 22 regions between 2006 and 2010. Participants French volunteer citizens (N=31 349) aged between 4 and 80 years old who participated in events dedicated to measuring physical fitness. Primary and secondary outcome measures We assessed the results of the following fitness tests: 20 m shuttle run, standing broad jump, repeated squat jump, 4×10 m shuttle run, speed, flexibility and push-ups in relation to age and body mass index (BMI) using Spearmans rho, a one-way analysis of variance. A bi-exponential model was used to represent the performance with age. Results Our major results showed higher performances for men and for subjects with normal BMI at all age groups except for the flexibility test. BMI was strongly correlated across all ages with physical fitness p<0.0001. Furthermore, through bi-exponential model, a mean peak performance was identified at 26.32 years of age for men and 22.18 years of age for women. Conclusions Physical fitness assessment using a simple series of tests on the general population offers an important indicator of health status. The possibility of observing the evolution of fitness levels with time provides an important monitoring method from a public health perspective. Further research is needed to reinforce and evaluate the approach.