Dr.Biol., Professor S.I. Loginov¹
PhD A.S. Kintyukhin¹
PhD, Associate Professor A.S. Snigirev¹
PhD R.O. Solodilov^1
1Surgut State University, Surgut

Keywords: walking index, oxygen consumption, physical activity, physical education and sports, physical fitness, walking cadence, walking speed, energy costs, body mass index.

Background. Presently the middle-age population (45-59 year-olds under the WHO classification) is estimated at 22% of the Russian total [2]. A few studies have demonstrated the group being in need of special physical activity although less committed for the institutional physical activity services than the young population on the whole and students in particular – that enjoy the academic physical education and sport services [3]. Middle-aged people are left alone in their physical education and sport needs; with some of them attending corporate gyms and swimming pools (when offered by their employers), or commercial fitness centers to improve their physical fitness standards. Walking may be recommended as the most accessible health-improvement physical activity that requires no special equipment or indoor spaces, with the highest health benefits secured by mid-intensity (3-6 METs) walking practices [5]. It should be emphasized, however, that there is still no clarity on the health benefits for the middle-aged groups of the walking pace i.e. stride and rhythm/ frequency – jointly referred to as the walking cadence (step/ min) [6] – that is normally rather individual (set instinctively on a preferential basis) on the 1km-plus walking distances. [1].

Objective of the study was to rate the walking cadence versus energy costs for the middle-aged population of the urban Yugra North communities.

Methods and structure of the study. We sampled for the study mid-age people (n=31), including the 41.1±9.4 year old men (n=18) and 42.3±9.7 year-old women (n=13), on their informed written consent and formal no-contraindication notes from doctors. The sample was tested by 30-minute speed-stepping Matrix treadmill tests, with the walking speeds stepped from 2 to 7 km/h and each speed step run for 5 minutes. Breathing and basal metabolism was tested by Fitmate Pro metabolograph (COSMED, Italy) to obtain respiratory rate (RR, times/ min), oxygen consumption (OC, ml/ min), relative oxygen consumption (ROC, ml/ min/ kg), and heart rate (HR, beats/ min) as dependent variables; with the oxygen consumption and heart rate data averaged every 15s, processed and saved for analysis.

Walking process was fixed by GoPro Hero 6 Black video camera rated at 120 frames/ s to obtain the full stride time (FST, s), mode amplitude (MA, %), walking index (WI, points), stride length (SL, mm); plus we measured the leg length (m), body length (m) and body weight (kg). walking index was computed as WI = MA / (2×Mo×dX), where Mo is the modal class, s; mode amplitude mode amplitude, %; and dX variation range of the interval, s. The test data were statistically processed using the Statistica v.10 (StatSoft, USA) software toolkit, with the distribution normality rated on a prior basis. We also computed the arithmetic mean (X), standard deviation (SD), and the 0.95 confidence interval (±0.95 CI) followed by correlation and regression analyses. Differences of the data arrays were rated by a two-tailed t-test for related and unrelated groups, as well as the nonparametric Wilcoxon-Mann-Whitney test with an insignificant threshold of p≤0.05.

Findings. The male group in the sample was tested with the higher body length and leg length than the female group (p <0.05), whilst the age, body weight and body mass index were tested virtually gender-unspecific: see Table 1. The relative oxygen consumption and respiratory rates (RR) were tested to grow with the walking speed, with all the other test rates found to grow at 4-plus km/h, save for the exhaled oxygen rate in the male group. In the female group, the latter was tested higher in the quiescent state and at 6 and 7 km/h versus the male group: see Table 2.

Table 1. Ages and anthropometric characteristics of the sample, X ± SD

Table 2. Cardiorespiratory system functionality test rates (X±SD), n=31

The stride biomechanics were tested to change with the walking speed. Thus the mode amplitude and stride length were tested to grow at 3-plus km/h (p <0.05), with no changes to the contact time and stride time: see Table 3. Walking index was tested to grow at 3-plus km/h in the both groups, with the particularly fast growth at 5 km/h for males and 4/ 5/ 6 km/h for females: see Table 3. Metabolic cost of the walking cadence was tested gender-specific. Thus the male and females groups made 74 and 86 strides/ min at 3 METs (moderate-intensity walking) and 126 and 132 strides/ min at 6 METs, respectively: see Figure 1.

Table 3. Walking biomechanics of the sample (X±SD), n=37

Note: FST full stride time, s; MA mode amplitude, %; WI walking index, points; SL stride length, mm; CT contact time, s; LMT leg move time, s; * p≤0,05 for 2 km/h versus 3÷7 km/h

Figure 1. Energy costs (MET) for male (A) and female (B) groups. Crosses mark the walking cadences at 3 MET and 6 MET. Dotted lines are the 0.95 confidence intervals

Walking cadence, steps/min

Discussion. The study was designed to rate the gender-specific walking cadence biomechanics and bioenergetics of middle-aged people. We found in our prior study [1] that the young people’s walking cadence is energy-dependent and makes up 96 and 92 steps/ min at 3 MET (moderate-intensity comfortable walking) for females and males, respectively; whilst at 6 METs (high-intensity walking), the walking cadence was tested at 142 and 141 strides/ min, respectively, and perceived uncomfortable by many: see Figure 2.

Figure 2. Energy costs (MET) for young male (A) and female (B) groups. Crosses mark the walking cadences at 3 MET and 6 MET. Dotted lines are the 0.95 confidence intervals

The middle-aged groups were tested with the walking cadence decreasing at the same energy costs that may be indicative of the lower working capacity of the sample – although we are uncertain whether or not it is representative for the Northern middle-aged population on the whole and, hence, further studies are recommended. The similar study tested the 18-20 year-olds with the walking cadences of 95.9 steps/min and 119.3 steps/min at 3 METs and 6 METs, respectively [6]. One more study found the higher walking cadence correlated with the higher energy costs [5]. The reasons may be the following: (1) high number of energy- and pace-inefficient steps; (2) energy cost growth due to the active feedback to optimize the walking sequence by higher muscular activity [4]. Therefore, it is not improbable that the walking cadence continuous adjustment mechanisms secure low variability stepwise and, hence, optimal energy costs in the integration of feed-forward (from internal models) and feedback (from sensory inputs) mechanisms.

In addition to the metabolic cost of an optimal cadence, we found the stride variations with walking speeds (walking index, WI) – based on an analysis of the FST series. We found the walking index growing with the walking speed growth from 2 to 7 km/h by 23.8 and 12.6 times men and women, respectively (see Table 2) – that may be interpreted as the high tension of the regulatory mechanisms.

Therefore, the Northern middle-aged population may be recommended moderate-to-high-intensity (3-6 MET) walking practices with cadences of 74-126 steps/ min and 86-132 steps/ min and waking indices of 816-1422 points and 546-1493 points for men and women, respectively.

The study was sponsored by the Khanty-Mansi Autonomous Yugra Territory’s Education and Youth Policy Department under the ‘New physical activity and health optimizing solutions with the physical activity profiled versus the body response logics” Research Project.

References

1. Loginov S.I., Kintyukhin A.S., Snigirev A.S., Solodilov R.O. Gender-Related Features of Biomechanics and Variability of Treadmill Walking in Young People in Laboratory Study. Teoriya i praktika fiz. kulturyi. 2020. No.1. pp. 87-89.
2. Russian population by gender and age: statistics, distribution. Statdata.ru. [Electronic resource]. Date of access: 11.03.2020.
3. Chaykovskaya O.E. Effect of motor activity on vitality of middle-aged people. Pedagogicheskiy zhurnal. 2018. v. 8. No. 1 А. pp. 354-360.
4. Donelan J.M., Shipman D.W., Kram R., Kuo A.D. Mechanical and metabolic requirements for active lateral stabilization in human walking. J. Biomech. 2004. V. 37. P. 827–835.
5. O’Connor S.M., Xu H.Z., Kuo A.D. Energetic cost of walking with increased step variability. Gait Posture. 2012. V. 36. pp. 102–107.
6. Tudor-Locke C., Han H., Aguiar E.J., Barreira T.V., Schuna J.M., Kang M., Rowe D.A. How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults: a narrative review. Br. J. Sports. Med. 2018. V. 52. N 12. P. 776-788. doi: 10.1136/bjsports-2017-097628.
7. Tudor-Locke C., Schuna J.M., Han H., Aguiar E.J., Larrivee S., Hsia D.S., Ducharme S.W., Barreira T.V., Johnson W.D. Cadence (steps/min) and intensity during ambulation in 6-20 year olds: the CADENCE-kids study. Int. J. Behav. Nutr. Phys. Act. 2018. V. 15. N 1. 20. doi: 10.1186/s12966-018-0651-y.

Corresponding author: logsi@list.ru

Abstract

Objective of the study was to rate the walking cadence versus energy costs for the middle-aged population of the urban Yugra North communities.

Methods and structure of the study. We sampled for the study mid-age people (n=31), including the 41.1±9.4 year old men (n=18) and 42.3±9.7 year-old women (n=13), on their informed written consent and formal no-contraindication notes from doctors. The sample was tested by 30-minute speed-stepping Matrix treadmill tests, with the walking speeds stepped from 2 to 7 km/h and each speed step run for 5 minutes. Breathing and basal metabolism was tested by Fitmate Pro metabolograph (COSMED, Italy) to obtain respiratory rate (RR, times/ min), oxygen consumption (OC, ml/ min), relative oxygen consumption (ROC, ml/ min/ kg), and heart rate (HR, beats/ min) as dependent variables; with the oxygen consumption and heart rate data averaged every 15s, processed and saved for analysis.

Results and conclusions. It was found that with the increasing walking speed, the studied indices increased as well (t-test, p<0.05). The dependence of energy consumption (E, MET) on the walking cadence (WC, steps/min) rate is expressed in the equation as follows: E = 6.18-0.102WC+0.0008WC² - in the males and E = 5.17-0.084WC+0.0007WC² - in the females, where E is the energy consumption in MET, WC is the walking cadence rate in steps/min; 0.102, 0.084, 0.0008 and 0.0007 are empirical coefficients. With an increase in the walking speed from 2 to 7 km/h, the walking index increased 23.9 times in the males and 12.6 times in the females, which may indicate a significant tension of the neuro-locomotor mechanisms of regulation of walking with the increasing speed.
Therefore, the Northern middle-aged population may be recommended moderate-to-high-intensity (3-6 MET) walking practices with cadences of 74-126 steps/ min and 86-132 steps/ min and waking indices of 816-1422 points and 546-1493 points for men and women, respectively