TY - JOUR

T1 - Aerobic Exercise Training Increases Muscle Water Content in Obese Middle-Age Men

AU - Mora-Rodríguez, Ricardo

AU - Sanchez-Roncero, Alicia

AU - Fernández-Elías, Valentin Emilio

AU - Guadalupe-Grau, Amelia

AU - Ortega, Juan Fernando

AU - Dela, Flemming

AU - Helge, Jorn Wulff

PY - 2016/5

Y1 - 2016/5

N2 - PURPOSE: The objective of this study is to determine whether muscle water content (H2Omuscle) expands with training in deconditioned middle-age men and the effects of this expansion in other muscle metabolites.METHODS: Eighteen obese (BMI = 33 ± 3 kg⁻¹·m⁻²) untrained (V˙O2peak = 29 ± 7 mL⁻¹·kg⁻¹·min⁻¹) metabolic syndrome men completed a 4-month aerobic cycling training program. Vastus lateralis muscle biopsies were collected before and 72 h after the completion of the last training bout. Water content, total protein, glycogen concentration, and citrate synthase activity were measured in biopsy tissue. Body composition was assessed using dual-energy X-ray absorptiometry, and cardiometabolic fitness was measured during an incremental cycling test.RESULTS: Body weight and fat mass were reduced -1.9% and -5.4%, respectively (P < 0.05), whereas leg fat free mass increased with training (1.8%, P = 0.023). Cardiorespiratory fitness (i.e., V˙O2peak), exercise maximal fat oxidation (i.e., FOmax), and maximal cycling power (i.e., Wmax) improved with training (11%, 33%, and 10%, respectively; P < 0.05). After 4 months of training, H2Omuscle increased from 783 ± 18 to 799 ± 24 g·kg⁻¹ wet weight (ww) (2%, P = 0.011), whereas muscle protein concentration decreased 11% (145 ± 15 to 129 ± 13 g·kg⁻¹ ww, P = 0.007). Citrate synthase activity (proxy for mitochondrial density) increased by 31% (17 ± 5 to 22 ± 5 mmol·min⁻¹·kg⁻¹ ww, P = 0.024). Muscle glycogen concentration increased by 14% (22 ± 7 to 25 ± 7 g·kg⁻¹ ww) although without reaching statistical significance when expressed as per kilogram of wet weight (P = 0.15).CONCLUSIONS: Our findings suggest that aerobic cycling training increases quadriceps muscle water although reduces muscle protein concentration in obese metabolic syndrome men. Reduced protein concentration coexists with increased leg lean mass suggestive of a water dilution effect that however does not impair increased cycling leg power with training.

AB - PURPOSE: The objective of this study is to determine whether muscle water content (H2Omuscle) expands with training in deconditioned middle-age men and the effects of this expansion in other muscle metabolites.METHODS: Eighteen obese (BMI = 33 ± 3 kg⁻¹·m⁻²) untrained (V˙O2peak = 29 ± 7 mL⁻¹·kg⁻¹·min⁻¹) metabolic syndrome men completed a 4-month aerobic cycling training program. Vastus lateralis muscle biopsies were collected before and 72 h after the completion of the last training bout. Water content, total protein, glycogen concentration, and citrate synthase activity were measured in biopsy tissue. Body composition was assessed using dual-energy X-ray absorptiometry, and cardiometabolic fitness was measured during an incremental cycling test.RESULTS: Body weight and fat mass were reduced -1.9% and -5.4%, respectively (P < 0.05), whereas leg fat free mass increased with training (1.8%, P = 0.023). Cardiorespiratory fitness (i.e., V˙O2peak), exercise maximal fat oxidation (i.e., FOmax), and maximal cycling power (i.e., Wmax) improved with training (11%, 33%, and 10%, respectively; P < 0.05). After 4 months of training, H2Omuscle increased from 783 ± 18 to 799 ± 24 g·kg⁻¹ wet weight (ww) (2%, P = 0.011), whereas muscle protein concentration decreased 11% (145 ± 15 to 129 ± 13 g·kg⁻¹ ww, P = 0.007). Citrate synthase activity (proxy for mitochondrial density) increased by 31% (17 ± 5 to 22 ± 5 mmol·min⁻¹·kg⁻¹ ww, P = 0.024). Muscle glycogen concentration increased by 14% (22 ± 7 to 25 ± 7 g·kg⁻¹ ww) although without reaching statistical significance when expressed as per kilogram of wet weight (P = 0.15).CONCLUSIONS: Our findings suggest that aerobic cycling training increases quadriceps muscle water although reduces muscle protein concentration in obese metabolic syndrome men. Reduced protein concentration coexists with increased leg lean mass suggestive of a water dilution effect that however does not impair increased cycling leg power with training.

U2 - 10.1249/MSS.0000000000000848

DO - 10.1249/MSS.0000000000000848

M3 - Journal article

C2 - 26694843

VL - 48

SP - 822

EP - 828

JO - Medicine and Science in Sports and Exercise

JF - Medicine and Science in Sports and Exercise

SN - 0195-9131

IS - 5

ER -