Table 3 Adjusted mean values of skeletal muscle index and hand grip strength according to the frequency or duration of physical activities in men and women

Walking-only group

n = 866

n = 1684

n = 1075

n = 2243

  Frequency

    1-3

7.1 ± 0.05

32.35 ± 0.343

5.92 ± 0.058

19.65 ± 0.424

    4-6

7.12 ± 0.062

32.9 ± 0.372

5.96 ± 0.064

20.13 ± 0.417

    everyday

7.15 ± 0.045

32.97 ± 0.272

5.96 ± 0.06

20.57 ± 0.418

    P

0.639

0.237

0.553

0.001

  Duration

    <3

7.03 ± 0.048

5.93 ± 0.057

32.08 ± 0.32

19.82 ± 0.414

    3- <7

7.14 ± 0.052

5.93 ± 0.065

32.96 ± 0.345

20.43 ± 0.419

    ≥7

7.18 ± 0.046

5.95 ± 0.061

33.36 ± 0.28

20.53 ± 0.441

    P

0.013

0.878

0.001

0.008

Moderate PA group

n = 426

n = 603

n = 567

n = 469

  Frequency

    1-3

7.19 ± 0.062

33.85 ± 0.605

6.11 ± 0.068

21.29 ± 0.976

    4-6

7.21 ± 0.081

34.87 ± 0.66

6.05 ± 0.076

22.07 ± 0.969

    everyday

7.3 ± 0.058

34.78 ± 0.645

6.13 ± 0.08

21.33 ± 1.014

    P

0.273

0.218

0.488

0.152

  Duration

    <3

7.16 ± 0.073

6.06 ± 0.07

33.85 ± 0.577

21.01 ± 0.916

    3- <7

7.26 ± 0.058

6.07 ± 0.072

34.46 ± 0.729

21.96 ± 0.961

    ≥7

7.24 ± 0.061

6.2 ± 0.082

35.57 ± 0.725

22.04 ± 1.025

    P

0.424

0.072

0.073

0.030

Vigorous PA group

n = 475

n = 227

n = 408

n = 97

  Frequency

    1-3

7.45 ± 0.057

36.84 ± 0.73

5.94 ± 0.09

22.23 ± 0.932

    4-6

7.39 ± 0.082

37.47 ± 0.947

6.08 ± 0.108

24.99 ± 1.051

    everyday

7.45 ± 0.076

38.55 ± 1.153

6.07 ± 0.119

21.94 ± 1.429

    P

0.748

0.369

0.058

0.011

  Duration

    <3

7.41 ± 0.076

5.76 ± 0.09

36.54 ± 0.688

24.15 ± 0.851

    3- <7

7.43 ± 0.058

6.06 ± 0.096

37.1 ± 0.853

23.00 ± 1.248

    ≥7

7.47 ± 0.07

6.08 ± 0.095

39.57 ± 1.124

24.69 ± 1.389

    P

0.792

<0.001

0.027

0.404