Validity of the Hausa IPAQ-SF for Walking and High-Intensity Activity: A Dual-Criterion Validation against accelerometry and VO2max

To understand how people move, scientists often rely on two very different ways of seeing the world. One way is to ask people to remember what they did, a method that is cheap and easy to use across large populations but relies entirely on human memory. The other way is to watch people move with machines that count every step and measure every beat of their heart, providing a hard, objective record of physical reality. The challenge lies in connecting these two perspectives. When researchers ask people to report their activity, they need to know if the answers match what actually happened. This is especially difficult when translating a questionnaire from one language to another, because words for "walking" or "hard work" can mean different things in different cultures. If a tool meant to track health habits gives the wrong picture, public health officials might miss the true state of a population's fitness, leading to ineffective policies.

In a recent study, researchers set out to test a specific version of a global health survey translated into Hausa, a language spoken by over 75 million people across West and Central Africa. They wanted to know if this translated questionnaire could accurately capture how university students in Nigeria moved during a typical week. To find the answer, they did not just ask students to fill out a form; they paired the self-reported answers with two objective measures. First, the students wore small, sensitive devices on their hips for seven days that recorded their every movement, distinguishing between sitting, walking, and running. Second, the students walked on a treadmill until their hearts were working hard, allowing researchers to estimate their overall fitness level. By comparing what the students said they did against what the machines recorded and what their bodies could physically sustain, the team could see exactly where the questionnaire worked and where it failed.

The study involved 106 university students, mostly in their early twenties, who completed the Hausa version of the physical activity questionnaire and then wore the motion-tracking devices for a full week. The results showed a clear split in performance. When it came to walking, the questionnaire worked reasonably well. The students' estimates of how much they walked matched the data from the motion trackers with a moderate level of accuracy. This success likely stems from the nature of university life in this region, where walking is a primary and structured way to get from one building to another, making it easier to remember and report accurately. However, the tool struggled significantly when asked about other types of movement. It failed to find a reliable link between what students said they did and what the machines recorded for moderate activities, such as light household chores or casual tasks, and it also failed to accurately capture how much time students spent sitting down.

Perhaps the most surprising finding concerned the students' reports of high-intensity, vigorous exercise. The researchers discovered a counterintuitive pattern: students who reported doing the most vigorous activity actually had the lowest levels of physical fitness. This suggests that the questionnaire was not measuring actual high-speed running or heavy lifting, but rather a feeling of effort. Students with lower fitness levels found everyday tasks, like climbing stairs or carrying heavy books, to be extremely strenuous. Because these tasks felt so hard to them, they labeled them as "vigorous" on the survey, even though the motion trackers showed they were not moving at high speeds. In contrast, students with high fitness levels could perform the same tasks with ease and did not report them as intense exercise. This reveals that the survey was capturing a person's perception of effort rather than their actual speed or power output.

Beyond these specific categories, the study found a consistent tendency for the questionnaire to overestimate total activity. On average, the students reported an activity volume equivalent to 142.5 MET-minutes per week more than what the motion trackers showed. This overestimation was not random; it grew larger for students who were already very active. Those who moved the most tended to exaggerate their activity levels the most, while those who moved less were closer to the truth. The researchers calculated that for every unit of activity a student actually did, the self-reported number grew disproportionately higher. This means that while the questionnaire can tell researchers if a group is generally active, it cannot be trusted to give an exact number of calories burned or minutes spent moving.

The researchers concluded that the Hausa version of this survey is a useful tool for tracking walking habits and identifying high-intensity movement patterns among young, educated adults who can read the language. However, it is not a perfect mirror of reality. It cannot accurately measure moderate daily tasks or sitting time, and it tends to inflate the total amount of activity people claim to do. For scientists and health officials, this means the survey should be used with caution. If they need to know exactly how much time people spend sitting or doing light work, they should not rely on the questionnaire alone. Instead, they should combine the survey with objective sensors, like the motion trackers used in this study, to get a complete and accurate picture of how people in this region are truly moving.