Outcomes | Sub-Group Comparison of Meta-Analysis | # of Individual Studies Included in Meta-Analysis | Number of Participants Included in Meta-Analysis | Weighted Mean Difference (WMD) | 95% Confidence Interval | P value of overall effect | I2 statistic (p value for heterogeneity) | Interpretation |
---|---|---|---|---|---|---|---|---|
Mean Body Weight (kg) | PRE or combined PRE and aerobic exercise compared with no exercise | 5 studies (Dolan 2006 [37]; Grinspoon 2000 [39]; Lox 1995 [40]; Spence 1990 [44]; Tiozzo 2011 [33]) | 129 | 2.50 kg | 0.32, 4.67 | 0.02a | 76% (p = 0.002) | Significant increase in body weight among exercisers compared with non-exercisers. |
PRE compared with no exercise | 2 studies | 46 | 4.24 kgb | 1.82, 6.66 | 0.0006a | 39% (p = 0.20) | Significant and potential clinically important increase in body weight among exercisers compared with non-exercisers. | |
Combined PRE and aerobic exercise compared with no exercise | 3 studies | 83 | 0.81 kg | −0.94, 2.56 | 0.37 | 19% (p = 0.29) | “No difference in change in body weight among exercisers compared with non-exercisers.” [12]. | |
PRE (or combined PRE and aerobic exercise) and diet and/or nutrition counselling group compared with diet and/or nutrition counselling alone. | 3 studies (Balasumbramanyam 2011 [26]; Ogalha 2011 [30]; Shevitz 2005 [43]) | 162 | −0.67 kg | −4.25, 2.92 | 0.72 | 93% (p < 0.00001) | “No difference in change in body weight for participants in the combined exercise and diet or nutrition counselling group compared with the diet or nutrition counselling alone group.” [12]. | |
PRE (or combined PRE and aerobic exercise) and testosterone compared with testosterone alone | 2 studies | 51 | 0.42 kg | −0.92, 1.77 | 0.54 | 0% (p = 0.48) | No difference in change in body weight for exercisers taking testosterone compared with those taking testosterone only. | |
Body Mass Index (kg/m2) | PRE or combined PRE and aerobic exercise compared with no exercise | 5 studies (Dolan 2006 [37]; Farinatti 2010 [27]; Fitch 2012 [28]; Lox 1995 [40]; Tiozzo 2011 [33]) | 131 | 0.40 kg/m2 | −0.22, 1.03 | 0.21 | 34% (p = 0.19) | “No difference in change in body mass index among exercisers compared with non-exercisers.” [12]. |
Combined PRE and aerobic exercise compared with no exercise | 4 studies (Dolan 2006 [37]; Farinatti 2010 [27]; Fitch 2012 [28]; Tiozzo 2011 [33]) | 109 | 0.21 kg/m2 | −0.27, 0.68 | 0.40 | 0% (p = 0.40) | “No difference in change in body mass index among exercisers compared with non-exercisers.” [12]. | |
PRE (or combined PRE and aerobic exercise) and diet and/or nutrition counselling group compared with diet and/or nutrition counselling alone | 3 studies (Balasubramanyam 2011 [26]; Ogalha 2011 [30]; Shevitz 2005 [43]) | 162 | −0.55 kg/m2 | −1.22, 0.12 | 0.11 | 83% (p = 0.002) | No difference in change in body mass index for participants in the combined PRE and diet or nutrition counselling group compared with the diet or nutrition counselling only group. | |
Lean Body Mass (kg) | PRE or combined PRE and aerobic exercise compared with no exercise | 4 studies (Farinatti 2010 [27]; Grinspoon 2000 [39]; Lox 1995 [40]; Perez-Moreno 2007 [31]) | 90 | 2.14 kg | −0.11, 4.39 | 0.06 | 59% (p = 0.06) | “No difference in change in lean body mass among exercisers compared with non-exercisers.” [12]. |
Combined PRE and aerobic exercise compared with no exercise | 3 studies (Farinatti 2010 [27], Grinspoon 2000 [39]; Perez-Moreno 2007 [31]) | 68 | 1.23 kg | −0.62, 3.08 | 0.19 | 17% (p = 0.30) | “No difference in change in lean body mass among exercisers compared with non-exercisers.” [12]. | |
PRE (or combined PRE and aerobic exercise) and testosterone compared with testosterone alone | 2 studies | 51 | 0.64 kg | −0.97, 2.26 | 0.44 | 0% (p = 0.63) | No difference in change in lean body mass for exercisers taking testosterone compared with those taking testosterone alone. | |
Leg Muscle Area (cm2 or mm2) | Combined PRE and aerobic exercise compared with no exercise | 2 studies | 60 | 4.79 cm2 | 2.04, 7.54 | 0.0007a | 11% (p = 0.29) | Significant increase in leg muscle area among exercisers compared with non-exercisers. |
PRE (or combined PRE and aerobic exercise) and testosterone compared with testosterone alone | 2 studies | 51 | 56.09 mm2 | −359.53, 471.72 | 0.79 | 0% (p = 0.67) | No difference in change in leg muscle area for exercisers taking testosterone compared with those taking testosterone only. | |
Fat Mass (kg) | PRE or combined PRE and aerobic exercise compared with no exercise | 4 studies (Dolan 2006 [37]; Fitch 2012 [28]; Grinspoon 2000 [39]; Lox 1995 [40]) | 103 | 0.36 kg | −0.50, 1.23 | 0.41 | 0% (p = 0.53) | “No difference in change in fat mass among exercisers compared with non-exercisers.” [12]. |
Combined PRE and aerobic exercise compared with no exercise | 3 studies | 81 | 0.18 kg | −0.74, 1.10 | 0.70 | 0% (p = 0.63) | “No difference in change in fat mass among exercisers compared with non-exercisers.” [12]. | |
PRE (or combined PRE and aerobic exercise) and testosterone compared with testosterone alone | 2 studies | 51 | −0.73 kg | −1.50, 0.04 | 0.06 | 0% (p = 0.86) | No difference in change in fat mass for exercisers taking testosterone compared with those taking testosterone only. | |
Waist Circumference (cm) | Combined PRE and aerobic exercise compared with no exercise | 3 studies | 82 | −1.33 cm | −4.21, 1.54 | 0.36 | 37% (p = 0.21) | “No difference in change in waist circumference among exercisers compared with non-exercisers.” [12]. |
Arm and Thigh Girth (cm) | PRE compared with no exercise | 2 studies | 46 | 7.91 cmb | 2.18, 13.65 | 0.007a | 67% (p = 0.08) | Significant and potential clinically important increase in arm and thigh girth among exercisers compared with non-exercisers. |