Physiological and Perceptual Responses to Nordic Walking in a Natural Mountain Environment

Abstract

Background: Interest around Nordic Walking (NW) has increased in recent years. However, direct comparisons of NW with normal walking (W), particularly in ecologically valid environments is lacking. The aim of our study was to compare NW and W, over long distances in a natural mountain environment. Methods: Twenty one subjects (13 male/8 female, aged 41 ± 12 years, body mass index BMI 24.1 ± 3.7), walked three distinct uphill paths (length 2.2/3.4/7 km) with (NW) or without (W) walking poles over two separate days. Heart rate (HR), energy expenditure (EE), step length (SL), walking speed (WS), total steps number (SN) and rating of perceived exertion (RPE) were monitored. Results: HR (+18%) and EE (+20%) were higher in NW than in W whilst RPE was similar. SN (-12%) was lower and SL (+15%) longer in NW. WS was higher (1.64 vs. 1.53 m s^-1) in NW. Conclusions: Our data confirm that, similarly to previous laboratory studies, differences in a range of walking variables are present between NW and W when performed in a natural environment. NW appears to increase EE compared to W, despite a similar RPE. Thus, NW could be a useful as aerobic training modality for weight control and cardiorespiratory fitness.

Keywords: RPE; energy expenditure; natural environment; pole walking locomotion; trekking.

Figure 1

Elevation profiles of the three different experimental paths.

Figure 2

Average of the Energy Consumption Estimation for the “mixed terrain path”, “the asphalt path” and the “off-road path”. If the grand means (mean of the means) were compared, the cost of locomotion was 19.5% higher with poles (nordic walking NW, 6.57 ± 0.54 kcal min⁻¹) than without poles (ordinary walking W, 5.49 ± 0.47 kcal min⁻¹).

Figure 3

Average heart rates of all subjects recorded during NW (continuous line) and W (dashed line) sessions in each path segment. As expected, heart rate (HR) was higher when hiking uphill than downhill, but in both cases it was higher in NW than in W. The slope of the regression line (continuous line) of the values recorded in NW vs. the values recorded in W had a value of 1.184 ± 0.007, significantly greater than 1 (dashed line), p < 0.001.

Figure 4

Average numbers of steps in the three tests are plotted for NW and W. The difference in step number implies a difference in stride length, which was calculated to be on average 0.92 ± 0.05 m in NW compared to 0.80 ± 0.04 m in W, using data of all subjects in the three tests (p < 0.001). In detail, average stride length on asphalt road (second test) was 0.82 ± 0.05 m in W and 0.97 ± 0.05 m in NW walking uphill and 0.82 ± 0.03 m in W and 0.93 ± 0.04 m in NW walking dowhill; on dirt path (third test) stride length was 0.79 ± 0.03 m in W and 0.88 ± 0.03 m in NW uphill and 0.77 ± 0.03 m in W and 0.88 ± 0.03 m in NW downhill.

Figure 5

Perceived Exertion Intensity The regression line was slightly but not significantly above the 1:1 correspondence line. The grand mean (mean of the means) of RPE was not different in NW compared to W (10.7 ± 1.5 in NW and 10.3 ± 1.3 in W). NW: dashed line and empty circles; W: continuous line and solid circles.