The effect of a high carbohydrate diet on running performance during a 30-km treadmill time trial

Summary The purpose of the present study was to examine the influence of a high carbohydrate diet on running performances during a 30-km treadmill time trial. Eighteen runners (12 men and 6 women) took part in this study and completed a 30-km time trial on a level treadmill without modifying their food intake (trial 1). The runners were then randomly assigned to a control or a carbohydrate (CHO) group. The CHO group supplemented their normal diets with additional carbohydrate in the form of confectionery products during the 7 days before trial 2; the control group matched the increased energy intake of the CHO group by consuming additional fat and protein. The mean (SEM) carbohydrate intake of both groups was 334 (22) g before trial 1, after which the CHO group consumed 566 (29) g · day^–1 for the first 3 days and 452 (26) g · day^–1 for the remaining 4 days of recovery. Although there was no overall difference between the performance times for the two groups during trial 2, the CHO group ran faster during the last 5 km of trial 2 than during trial^–1 [3.64 (0.24) m · s^–1 vs 3.44 (0.26) m · s^–1 P < 0.05] . Furthermore, the 6 men in the CHO group ran the 30 km faster after carbohydrate loading [131.0 (5.4) min vs 127.4 (4.9) min;P < 0.05], whereas there was no such improvement in times of the men in the control group. Blood glucose concentrations of both groups decreased below pre-exercise values during trial^–1 (P < 0.001), but only the control group had a decrease in blood glucose concentrations during trial 2 (P < 0.001). There were no differences between the concentrations of plasma catecholamines of the control group during the two trials. However, the adrenaline concentrations of the CHO group were lower (P < 0.05) during trial 2 than during trial 1, even though they ran faster during trial 2. These results confirm that dietary carbohydrate loading improves endurance performance during prolonged running and that confectionery can be used as an effective means of supplementing the normal carbohydrate intake in preparation for endurance races.     

Oxygen uptake during running as related to body mass in circumpubertal boys: a longitudinal study

Summary To investigate the effect of endurance training on physiological characteristics during circumpubertal growth, eight young runners (mean starting age 12 years) were studied every 6 months for 8 years. Four other boys served as untrained controls. Oxygen uptake ( O ₂) and blood lactate concentrations were measured during submaximal and maximal treadmill running. The data were aligned with each individual's age of peak height velocity. The maximal oxygen uptake ( O _2max; ml · kg^–1 · min^–1) decreased with growth in the untrained group but remained almost constant in the training group. The oxygen cost of running at 15 km · h^–1 ( O ₂₁₅, ml · kg^–1 · min^–1) was persistently lower in the trained group but decreased similarly with age in both groups. The development of O _2max and O ₂₁₅ (1 · min^–1) was related to each individual's increase in body mass so that power functions were obtained. The mean body mass scaling factor was 0.78 (SEM 0.07) and 1.01 (SEM 0.04) for O _2max and 0.75 (SEM 0.09) and 0.75 (SEM 0.02) for O ₂₁₅ in the untrained and trained groups, respectively. Therefore, expressed as ml · kg^–0.75 · min^–1, O ₂₁₅ was unchanged in both groups and O _2max increased only in the trained group. The running velocity corresponding to 4 mmol · 1^–1 of blood lactate ( _la4) increased only in the trained group. Blood lactate concentration at exhaustion remained constant in both groups over the years studied. In conclusion, recent and the present findings would suggest that changes in the oxygen cost of running and O _2max (ml · kg^–1 · min^–1) during growth may mainly be due to an overestimation of the body mass dependency of O ₀₂ during running. The O ₂ determined during treadmill running may be better related to kg^0.75 than to kg¹.     

Association between anaerobic components of the maximal accumulated oxygen deficit and 30-second Wingate test

The purpose of this study was to analyze the relationship between the anaerobiccomponents of the maximal accumulated oxygen deficit (MAOD) and of the 30-secondWingate anaerobic test (30-WAnT). Nine male physical education students performed: a)a maximal incremental exercise test; b) a supramaximal constant workload test todetermine the anaerobic components of the MAOD; and c) a 30-WAnT to measure the peakpower (PP) and mean power (MP). The fast component of the excess post-exercise oxygenconsumption and blood lactate accumulation were measured after the supramaximalconstant workload test in order to determine the contributions made by alactic(AL_MET) and lactic (LA_MET) metabolism. Significantcorrelations were found between PP and AL_MET (r=0.71; P=0.033) and betweenMP and LA_MET (r=0.72; P=0.030). The study results suggested that theanaerobic components of the MAOD and of the 30-WAnT are similarly applicable in theassessment of AL_MET and LA_MET during high-intensityexercise.     

Relationship between record time and maximal oxygen consumption in middle-distance running

Summary The relationship between record time (t _r) and maximal oxygen uptake ( ) has been examined in 69 male physical education students who had taken part in 800-m and 1500-m footraces. It was found thatt _r and were inversely related. The relationshipst _r=f( ) have been fitted by two exponential equations:t _r(1500 m)=698e –0.0145 t _r(800 m) = 272e^–0.01 P<0.001. A mathematical formulation of the energy conservation principle in supramaximal running, based on the exponential increase of the oxygen uptake as a function of time with a rate constant of 0.025 s^–1 has been applied to thet _r calculation from . As calculatedt _r were highly correlated to measuredt _r (P<0.001), it was concluded that the relationshipst _r=f( ) can be interpreted on the basis of the model described in this study.     

Peak power output predicts maximal oxygen uptake and performance time in trained cyclists

Summary The purposes of this study were firstly to determine the relationship between the peak power output (W _peak) and maximal oxygen uptake (VO_2max) attained during a laboratory cycling test to exhaustion, and secondly to assess the relationship betweenW _peak and times in a 20-km cycling trial. One hundred trained cyclists (54 men, 46 women) participated in the first part of this investigation. Each cyclist performed a minimum of one maximal test during whichW _max andVO_2max were determined. For the second part of the study 19 cyclists completed a maximal test for the determination ofW _peak, and also a 20-km cycling time trial. Highly significant relationships were obtained betweenW _peak andVO_2max (r=0.97,P<0.0001) and betweenW _peak and 20-km cycle time (r= –0.91,P<0.001). Thus,W _peak explained 94% of the variance in measuredVO_2max and 82% of the variability in cycle time over 20 km. We concluded that for trained cyclists, theVO_2max can be accurately predicted fromW _peak, and thatW _peak is a valid predictor of 20-km cycle time.     

Neuromuscular characteristics and fatigue in endurance and sprint athletes during a new anaerobic power test

The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted ofn x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la^–]_b was measured after each run to determine submaximal and maximal indices of anaerobic power (P _3mmol·1 ^–1,P_5mmol·1 ^–1,P_10mmol·1 ^–1andP _max) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml·kg^–1·min^–1)=0.2·velocity (m·min^–1) +0.9·slope of treadmill (frac)·velocity (m·min^–1)+3.5. The height of rise of the centre of gravity of the counter movement jumps before (CMJ_rest) and during (CMJ) the MARP test, as well as the time of force production (t _F) and electromyographic (EMG) activity of the leg muscles of CMJ performed after each run were used to describe the neuromuscular performance characteristics. The maximal oxygen uptake ( _max), anaerobic and aerobic thresholds were determined in the _max test, which consisted ofn x 3-min runs on the treadmill. In the MARP-testP _max did not differ significantly between the endurance [116 (SD 6) ml·kg^–1·min^–1] and sprint [120 (SD 4) ml·kg^–1·min^–1] groups, even though CMJ_rest and peak [la^–]_b were significantly higher and _max was significantly lower in the sprint group than in the endurance group and CMJ_rest height correlated withP _max (r=0.50,P<0.05). The endurance athletes had significantly higher mean values ofP _3mmol·1 ^–1andP _5mmol·1 ^–1[89 (SD 7) vs 76 (SD 8) ml·kg^–1·min^–,P<0.001 and 101 (SD 5) vs 90 (SD 8) ml·kg^–1·min^–1,P<0.01. Significant positive correlations were observed between theP _3mmol·l ^–1and _max, anaerobic and aerobic thresholds. In the sprint group CMJ and the averaged integrated iEMG decreased andt _F increased significantly during the MARP test, while no significant changes occurred in the endurance group. The present findings would suggest thatP _max reflected in the main the lactacid power and capacity and to a smaller extent alactacid power and capacity. The duration of the MARP test and the large number of CMJ may have induced considerable energy and neuromuscular fatigue in the sprint athletes preventing them from producing their highest alactacidP _max at the end of the MARP test. Due to lower submaximal [la^–]_b (anaerobic sprinting economy) the endurance athletes were able to reach almost the sameP _max as the sprint athletes.     

The effects of dietary manipulation upon the respiratory exchange ratio as a predictor of maximum oxygen uptake during fixed term maximal incremental exercise in man

Summary This study examined the effects of dietary manipulation upon the respiratory exchange ratio ( ) as a predictor of maximum oxygen uptake ( ). Seven healthy males performed fixed term maximal incremental treadmill exercise after an overnight fast on three separate occasions. The first test took place after the subjects had consumed their normal mixed diet (45±5% carbohydrate (CHO)) for a period of three days. This test protocol was then repeated after three days of a low CHO diet (3±2% CHO), and again after three days of a high CHO diet (61±5% CHO). Respiratory gases were continuously monitored during each test using an online system. No significant changes in mean exercise oxygen uptake ( ), or maximum functional heart rate (FHR_max) were found between tests. Mean exercise carbon dioxide output ( ) and R were significantly lower than normal after the low CHO diet (bothp<0.001) and significantly higher than normal after the high CHO diet (bothp<0.05). Moreover, compared with the normal CHO diet, the R-time relationship during exercise was at all times significantly (p<0.001) shifted to the right after the low CHO diet, and shifted to the left, being significantly so (p<0.05) over the final 5 min of exercise, after the high CHO diet. As a result, predictions of based on the R-time relationship were similar to recorded after the normal CHO dietary condition (-1.5±1.9%), but higher after the low CHO diet (+14.8±3.9%,p<0.001) and lower after the high CHO diet (–7.0±4.5%,p<0.01). These results indicate that dietary manipulation can significantly affect respiratory gas exchanges during fixed term maximal incremental exercise, and by doing so can significantly influence predictions of based on R.     

Maximal oxygen uptake,anaerobic threshold and running economy in women and men with similar performances level in marathons

Sex differences in running economy (gross oxygen cost of running, C_R), maximal oxygen uptake (VO_2max), anaerobic threshold (Th_an), percentage utilization of aerobic power (% VO_2max), and Th_an during running were investigated. There were six men and six women aged 20–30 years with a performance time of 2 h 40 min over the marathon distance. The VO_2max, Th_an, and CR were measured during controlled running on a treadmill at 1° and 3° gradient. From each subject's recorded time of running in the marathon, the average speed (v _M) was calculated and maintained during the treadmill running for 11 min. The VO_{2 max} was inversely related to body mass (m _b), there were no sex differences, and the mean values of the reduced exponent were 0.65 for women and 0.81 for men. These results indicate that for running the unit ml·kg^–0.75·min^–1 is convenient when comparing individuals with different m _b. The VO_2max was about 10% (23 ml·kg^–0.75·min^–1) higher in the men than in the women. The women had on the average 10–12 ml·kg^–0.75·min^–1 lower VO₂ than the men when running at comparable velocities. Disregarding sex, the mean value of C_R was 0.211 (SEM 0.005) ml·kg^–1·m^–1 (resting included), and was independent of treadmill speed. No sex differences in Th_an expressed as % VO_2max or percentage maximal heart rate were found, but Than expressed as VO₂ in ml·kg^–0.75·min^–1 was significantly higher in the men compared to the women. The percentage utilization of f _emax and concentration of blood lactate at v _M was higher for the female runners. The women ran 2 days more each week than the men over the first 4 months during the half year preceding the marathon race. It was concluded that the higher VO_2max and Th_an in the men was compensated for by more running, superior C_R, and a higher exercise intensity during the race in the performance-matched female marathon runners.     

Critical determinants of endurance performance in middle-aged and elderly endurance runners with heterogeneous training habits

Summary The current investigation was designed to determine which factor or what combination of factors would best account for distance running performance in middle-aged and elderly runners (mean age 57.5 years SD±9.7) with heterogeneous training habits. Among 35 independent variables which were arbitrarily selected as possible prerequisites in the distance running performance of these runners, oxygen uptake at lactate threshold (LT) (r=0.781∼0.889), maximal oxygen uptake (r=0.751∼0.886), and chronological age (r=−0.736∼−0.886) were found to be the 3 predictor variables showing the highest correlations with the mean running velocity at 5 km (V _{5 km}), 10 km (V _{10 km}), and marathon (V _M). When all independent variables were used in a multiple regression analysis, any 3 or 4 variables selected from among at LT, chronological age, systolic blood pressure (SBP), atherogenic index (AI), and Katsura index (KI) were found to give the best explanation ofV _{5 km},V _{10 km}, orV _M in a combined linear model. Linear multiple regression equations constructed for predicting the running performances were:V _{5 km}=0.046X ₁−0.026X ₂−0.0056X ₃+5.17,V _{10 km}=0.028X ₁−0.028X ₂−0.190X ₄−1.34X ₅+6.45, andV _M=−0.0400X ₂−0.324X ₄−1.16X ₅+7.36, where at LT (ml·min⁻¹·kg⁻¹),X ₂ = chronological age,X ₃=SBP,X ₄=AI, andX ₅=KI. We suggest that distance running performance of middle-aged and elderly runners could be predicted with a relatively high accuracy by a single predictor of at LT or , or by a combination of either of these predictors with more easily measurable indices such as age, AI, KI, or SBP. The prediction equations which have been developed can be applied to a larger population of middle-aged and elderly runners. Data were collected at the Human Performance Laboratory, Hiroshima University     

In vitro aerobic and anaerobic muscle capacities in the European eel, Anguilla anguilla: effects of a swimming session

In order to have a general view of metabolic requirements during swimming, in vitro aerobic and anaerobic fluxes were measured in red and white muscles from silver eels and yellow eels which differ in activity levels and nutritional states. These measurements were performed in control eels and after a 4 day swimming session (70% U(crit) in yellow eels, 80% U(crit) in silver eels). A swimming session significantly increases U(crit) from 12% to 18%, depending on the stage, with a significantly higher in vitro energy cost during the yellow stage at the muscle level. In vitro, the swimming session brings about a gain in anaerobic capacities rather than in aerobic ones. Some in vivo hypotheses are proposed.     

Change point in V˙CO2 during incremental exercise test: a new method for assessment of human exercise tolerance

The main purpose of this study was to present a new method to determine the level of power output (PO) at which V˙CO ₂ during incremental exercise test (IT) begins to rise non-linearly in relation to power output (PO) – the change point in V˙CO ₂ (CP-V˙CO ₂). Twenty-two healthy non-smoking men (mean ± SD: age 22.0 ± 0.9 years; body mass 74.5 ± 7.5 kg; height 181 ± 7 cm; V˙O _2max 3.753 ± 0.335 l min^–1) performed an IT on a cycloergometer. The IT started at a PO of 30 W, followed by gradual increases of 30 W every 3 min. Antecubital venous blood samples were taken at the end of each step and analysed for plasma lactate concentration [La]_pl, blood PO ₂, PCO ₂ [HCO₃^–]_b and [H⁺]_b. In the detection of the change-point V˙CO ₂ (CP-V˙CO ₂), a two-phase model was assumed for the ‘third-minute-data’ of each step of the test. In the first phase, a linear relationship between V˙CO ₂ and PO was assumed, whereas in the second, an additional increase in V˙CO ₂ was allowed, above the values expected from the linear model. The PO at which the first phase ends is called the change point in V˙CO ₂. The identification of the model consists of two steps: testing for the existence of the change point, and estimating its location. Both procedures are based on suitably normalized recursive residuals (see 32 . Eur J Appl Physiol 78 , 369–377). In the case of each of our subjects it was possible to detect the CP-V˙CO ₂ and the CP-V˙O ₂ as described in our model. The PO at the CP-V˙CO ₂ amounted to 134 ± 42 W. The CP- V˙O ₂ was detected at 136 ± 32 W, whereas the PO at the LT amounted to 128 ± 30 W and corresponded to 49 ± 11, 49 ± 8 and 47 ± 8.6% V˙O _2max, respectively, for the CP-V˙CO ₂, CP-V˙O ₂ and the LT. The [La]_pl at the CP-V˙CO ₂ (2.65 ± 0.76 mmol L^–1), at the CP-V˙O ₂ (2.53 ± 0.56 mmol L^–1) and at the LT (2.25 ± 0.49 mmol L^–1) were already significantly higher (P < 0.01, Students t-test) than the value reached at rest (1.86 ± 0.43 mmol L^–1). Our study illustrates that the CP-V˙CO ₂ and the CP-V˙O ₂ occur at a very similar power output as the LT. We therefore postulate that the CP-V˙CO ₂ and the CP-V˙O ₂ be applied as an additional criterion to assess human exercise tolerance.     

Glycolytic pathway candidate markers in the prognosis of oral squamous cell carcinoma: a systematic review with meta-analysis

Molecular changes that affect mitochondrial glycolysis have been associated with the maintenance of tumor cells. Some metabolic factors have already been described as predictors of disease severity and outcomes. This systematic review was conducted to answer the question: Is the glycolytic pathway correlated with the prognosis of oral squamous cell carcinoma (OSCC)? A search strategy was developed to retrieve studies in English from PubMed, Scopus, and ISI Web of Science using keywords related to squamous cell carcinoma, survival, and glycolytic pathway, with no restriction of publication date. The search retrieved 1273 publications. After the titles and abstracts were analyzed, 27 studies met inclusion criteria. Studies were divided into groups according to two subtopics, glycolytic pathways and diagnosis, which describe the glycolytic profile of OSCC tumors. Several components of tumor energy metabolism found in this review are important predictors of survival of patients with OSCC.     

Intensity and physiological responses to the 6-minute walk test in middle-aged and older adults: a comparison with cardiopulmonary exercise testing

The 6-minute walk test (6MWT) is a simple field test that is widely used in clinical settings to assess functional exercise capacity. However, studies with healthy subjects are scarce. We hypothesized that the 6MWT might be useful to assess exercise capacity in healthy subjects. The purpose of this study was to evaluate 6MWT intensity in middle-aged and older adults, as well as to develop a simple equation to predict oxygen uptake (V˙O2) from the 6-min walk distance (6MWD). Eighty-six participants, 40 men and 46 women, 40-74 years of age and with a mean body mass index of 28±6 kg/m², performed the 6MWT according to American Thoracic Society guidelines. Physiological responses were evaluated during the 6MWT using a K4b2 Cosmed telemetry gas analyzer. On a different occasion, the subjects performed ramp protocol cardiopulmonary exercise testing (CPET) on a treadmill. Peak V˙O2 in the 6MWT corresponded to 78±13% of the peak V˙O2 during CPET, and the maximum heart rate corresponded to 80±23% of that obtained in CPET. Peak V˙O2 in CPET was adequately predicted by the 6MWD by a linear regression equation: V˙O2 mL·min^-1·kg^-1 = -2.863 + (0.0563×6MWD_m) (R²=0.76). The 6MWT represents a moderate-to-high intensity activity in middle-aged and older adults and proved to be useful for predicting cardiorespiratory fitness in the present study. Our results suggest that the 6MWT may also be useful in asymptomatic individuals, and its use in walk-based conditioning programs should be encouraged.     

Reduced premovement positivity during the stimulus‐response interval precedes errors: Using single‐trial and regression ERPs to understand performance deficits in ADHD

Brain mechanisms linked to incorrect response selections made under time pressure during cognitive task performance are poorly understood, particularly in adolescents with attention‐deficit hyperactivity disorder (ADHD). Using subject‐specific multimodal imaging (electroencephalogram, magnetic resonance imaging, behavior) during flanker task performance by a sample of 94 human adolescents (mean age = 15.5 years, 50% female) with varying degrees of ADHD symptomatology, we examined the degree to which amplitude features of source‐resolved event‐related potentials (ERPs) from brain‐independent component processes within a critical (but often ignored) period in the action selection process, the stimulus‐response interval, were associated with motor response errors (across trials) and error rates (across individuals). Response errors were typically preceded by two smaller peaks in both trial‐level and trial‐averaged ERP projections from posterior medial frontal cortex (pMFC): a frontocentral P3 peaking about 390 ms after stimulus onset, and a premovement positivity (PMP) peaking about 110 ms before the motor response. Separating overlapping stimulus‐locked and response‐locked ERP contributions using a “regression ERP” approach showed that trial errors and participant error rates were primarily associated with smaller PMP, and not with frontocentral P3. Moreover, smaller PMP mediated the association between larger numbers of errors and ADHD symptoms, suggesting the possible value of using PMP as an intervention target to remediate performance deficits in ADHD.     

Associations between objectively measured and self‐reported sleep with academic and cognitive performance in adolescents: DADOS study

Adequate sleep has been positively related with health and school achievement outcomes during adolescence. The aim of this study was to investigate the associations of objectively measured and self‐reported sleep duration and quality with academic and cognitive performance in adolescents. This study was conducted with 257 adolescents (13.9 ± 0.3 years) from the DADOS study (Deporte, ADOlescencia y Salud). Objectively measured and self‐reported sleep duration and quality were obtained by a wrist‐worn GENEActiv accelerometer and the Spanish version of Pittsburgh Sleep Quality Index questionnaire, respectively. Academic performance was analysed through school records using four indicators: math, language, science and grade point average score. Cognitive performance was measured using the Spanish version of the “SRA Test of Educational Ability”. After Benjamini–Hochberg correction for the false discovery rate, objectively measured sleep duration was negatively associated with verbal ability (β = ?0.179, p = .004), whilst self‐reported sleep quality was positively associated with academic performance (β ranging from 0.209 to 0.273; all p < .001). These associations remained significant after further controlling for physical fitness and physical activity. Conversely, there were no associations between self‐reported sleep duration and objective sleep quality with academic and cognitive performance. Our findings fit in line with previous research showing that sleep quality may play an important role on adolescents’ academic performance. Further interventional research is needed to clarify the mechanisms by which sleep is related to academic performance in youth.     

Long-term efficacy of a rural community-based integrated intervention for prevention and management of chronic obstructive pulmonary disease: a cluster randomized controlled trial in China's rural areas

This study aimed to assess the efficacy of a rural community-based integratedintervention for early prevention and management of chronic obstructive pulmonarydisease (COPD) in China. This 18-year cluster-randomized controlled trialencompassing 15 villages included 1008 patients (454 men and 40 women in theintervention group [mean age, 54 ± 10 years]; 482 men and 32 women in the controlgroup [mean age, 53 ± 10 years]) with confirmed COPD or at risk for COPD. Villageswere randomly assigned to the intervention or the control group, and studyparticipants residing within the villages received treatment accordingly.Intervention group patients took part in a program that included systematic healtheducation, smoking cessation counseling, and education on management of COPD. Controlgroup patients received usual care. The groups were compared after 18 years regardingthe incidence of COPD, decline in lung function, and mortality of COPD. COPDincidence was lower in the intervention group than in the control group (10%vs 16%, <0.05). A decline in lung function was alsosignificantly delayed in the intervention group compared to the control group of COPDand high-risk patients. The intervention group showed significant improvement insmoking cessation compared with the control group, and smokers in the interventiongroup had lower smoking indices than in the control group (350 vs450, <0.05). The intervention group also had a significantly lower cumulativeCOPD-related death rate than the control group (37% vs 47%,<0.05). A rural community-based integrated intervention is effective in reducingthe incidence of COPD among those at risk, delaying a decline in lung function inCOPD patients and those at risk, and reducing mortality of COPD.     

Handheld computers for survey and trial data collection in resource-poor settings: Development and evaluation of PDACT, a Palm™ Pilot interviewing system

Objective

Handheld computers (personal digital assistant, PDA) have the potential to reduce the logistic burden, cost, and error rate of paper-based health research data collection, but there is a lack of appropriate software. The present work describes the development and evaluation of PDACT, a Personal Data Collection Toolset (www.healthware.org/pdact/index.htm) for the Palm™ Pilot handheld computer for interviewer-administered and respondent-administered data collection.

Methods

We developed Personal Data Collection Toolkit (PDACT) software to enable questionnaires developed in QDS™ Design Studio, a Windows™ application, to be compiled and completed on Palm™ Pilot devices and evaluated in several representative field survey settings.

Results

The software has been used in seven separate studies and in over 90,000 interviews. Five interviewer-administered studies were completed in rural settings with poor communications infrastructure, following one day of interviewer training. Two respondent-administered questionnaire studies were completed by learners, in urban secondary schools, after 15 min training.Questionnaires were available on each handheld in up to 11 languages, ranged from 20 to 580 questions, and took between 15 and 90 min to complete. Up to 200 Palm™ Pilot devices were in use on a single day and, in about 50 device-years of use, very few technical problems were found. Compared with paper-based collection, data validation and cleaning times were reduced, and fewer errors were found.PDA data collection is easy to use and preferred by interviewers and respondents (both respondent-administered and interviewer-administered) over paper. Data are compiled and available within hours of collection facilitating data quality assurance. Although hardware increases the setup cost of the first study, the cumulative cost falls thereafter, and converges on the cumulative cost of paper-based studies (four, in the case of our interviewer-administered studies).

Conclusion

Handheld data collection is an appropriate, affordable and convenient technology for health data collection, in diverse settings.