The effect of exercise training on the course of cardiac troponin T and i levels: Three independent training studies

With the introduction of high-sensitive assays, cardiac troponins became potential biomarkers for risk stratification and prognostic medicine. Observational studies have reported an inverse association between physical activity and basal cardiac troponin levels. However, causality has never been demonstrated. This study investigated whether basal cardiac troponin concentrations are receptive to lifestyle interventions such as exercise training. Basal high-sensitive cardiac troponin T ( cTnT ) and I ( cTnI ) were monitored in two resistance-type exercise training programs ( 12-week ( study 1 ) and 24-week ( study 2 ) ) in older adults ( ≥65 years ). In addition, a retrospective analysis for high sensitive troponin I in a 24-week exercise controlled trial in ( pre )frail older adults was performed ( study 3 ). In total, 91 subjects were included in the final data analyses. There were no significant changes in cardiac troponin levels over time in study 1 and 2 ( study 1: cTnT −0.13 ( −0.33–+0.08 ) ng/L/12-weeks, cTnI −0.10 ( −0.33–+0.12 ) ng/L/12-weeks; study 2: cTnT −1.99 ( −4.79–+0.81 ) ng/L/24-weeks, cTnI −1.59 ( −5.70–+2.51 ) ng/L/24-weeks ). Neither was there a significant interaction between training and the course of cardiac troponin in study 3 ( p = 0.27 ). In conclusion, this study provides no evidence that prolonged resistance-type exercise training can modulate basal cardiac troponin levels

There are no nonresponders to resistance-type exercise training inolder men and women

Objective: To assess the proposed prevalence of unresponsiveness of older men and women to augment lean body mass, muscle fiber size, muscle strength, and/or physical function following prolonged resistance-type exercise training. Design/Setting/Participants: A retrospective analysis of the adaptive response to 12 (n ¼ 110) and 24 (n ¼ 85) weeks of supervised resistance-type exercise training in older ( > 65 years) men and women. Measurements: Lean body mass (DXA), type I and type II muscle fiber size (biopsy), leg strength (1-RM on leg press and leg extension), and physical function (chair-rise time) were assessed at baseline, and after 12 and 24 weeks of resistance-type exercise training. Results: Lean body mass increased by 0.9 0.1 kg (range: 3.3 to þ5.4 kg; P < .001) from 0 to 12 weeks of training. From 0 to 24 weeks, lean body mass increased by 1.1 0.2 kg (range: 1.8 to þ9.2 kg; P < .001). Type I and II muscle fiber size increased by 324 137 mm2 (range: 4458 to þ3386 mm2; P ¼ .021), and 701 137 mm2 (range: 4041 to þ3904 mm2; P < .001) from 0 to 12 weeks. From 0 to 24 weeks, type I and II muscle fiber size increased by 360 157 mm2 (range: 3531 to þ3426 mm2; P ¼ .026) and 779 161 mm2 (range: 2728 to þ3815 mm2; P < .001). The 1-RM strength on the leg press and leg extension increased by 33 2 kg (range: 36 to þ87 kg; P < .001) and 20 1 kg (range: 22 to þ56 kg; P < .001) from 0 to 12 weeks. From 0 to 24 weeks, leg press and leg extension 1-RM increased by 50 3 kg (range: 28 to þ145 kg; P < .001) and 29 2 kg (range: 19 to þ60 kg; P < .001). Chair-rise time decreased by 1.3 0.4 seconds (range: þ21.6 to 12.5 seconds; P ¼ .003) from 0 to 12 weeks. From 0 to 24 weeks, chair-rise time decreased by 2.3 0.4 seconds (range: þ10.5 to 23.0 seconds; P < .001). Nonresponsiveness was not apparent in any subject, as a positive adaptive response on at least one training outcome was apparent in every subject. Conclusions: A large heterogeneity was apparent in the adaptive response to prolonged resistance-type exercise training when changes in lean body mass, muscle fiber size, strength, and physical function were assessed in older men and women. The level of responsiveness was strongly affected by the duration of the exercise intervention, with more positive responses following more prolonged exercise training. We conclude that there are no nonresponders to the benefits of resistance-type exercise training on lean body mass, fiber size, strength, or function in the older population. Consequently, resistance-type exercise should be promoted without restriction to support healthy aging in the older population

There Are No Nonresponders to Resistance-Type Exercise Training in Older Men and Women

Objective: To assess the proposed prevalence of unresponsiveness of older men and women to augment lean body mass, muscle fiber size, muscle strength, and/or physical function following prolonged resistance-type exercise training. Design/Setting/Participants: A retrospective analysis of the adaptive response to 12 (n ¼ 110) and 24 (n ¼ 85) weeks of supervised resistance-type exercise training in older ( > 65 years) men and women. Measurements: Lean body mass (DXA), type I and type II muscle fiber size (biopsy), leg strength (1-RM on leg press and leg extension), and physical function (chair-rise time) were assessed at baseline, and after 12 and 24 weeks of resistance-type exercise training. Results: Lean body mass increased by 0.9 0.1 kg (range: 3.3 to þ5.4 kg; P < .001) from 0 to 12 weeks of training. From 0 to 24 weeks, lean body mass increased by 1.1 0.2 kg (range: 1.8 to þ9.2 kg; P < .001). Type I and II muscle fiber size increased by 324 137 mm2 (range: 4458 to þ3386 mm2; P ¼ .021), and 701 137 mm2 (range: 4041 to þ3904 mm2; P < .001) from 0 to 12 weeks. From 0 to 24 weeks, type I and II muscle fiber size increased by 360 157 mm2 (range: 3531 to þ3426 mm2; P ¼ .026) and 779 161 mm2 (range: 2728 to þ3815 mm2; P < .001). The 1-RM strength on the leg press and leg extension increased by 33 2 kg (range: 36 to þ87 kg; P < .001) and 20 1 kg (range: 22 to þ56 kg; P < .001) from 0 to 12 weeks. From 0 to 24 weeks, leg press and leg extension 1-RM increased by 50 3 kg (range: 28 to þ145 kg; P < .001) and 29 2 kg (range: 19 to þ60 kg; P < .001). Chair-rise time decreased by 1.3 0.4 seconds (range: þ21.6 to 12.5 seconds; P ¼ .003) from 0 to 12 weeks. From 0 to 24 weeks, chair-rise time decreased by 2.3 0.4 seconds (range: þ10.5 to 23.0 seconds; P < .001). Nonresponsiveness was not apparent in any subject, as a positive adaptive response on at least one training outcome was apparent in every subject. Conclusions: A large heterogeneity was apparent in the adaptive response to prolonged resistance-type exercise training when changes in lean body mass, muscle fiber size, strength, and physical function were assessed in older men and women. The level of responsiveness was strongly affected by the duration of the exercise intervention, with more positive responses following more prolonged exercise training. We conclude that there are no nonresponders to the benefits of resistance-type exercise training on lean body mass, fiber size, strength, or function in the older population. Consequently, resistance-type exercise should be promoted without restriction to support healthy aging in the older population

Extensive Type II Muscle Fiber Atrophy in Elderly Female Hip Fracture Patients

Background Sarcopenia, or the loss of muscle mass and strength, is known to increase the risk for falls and (hip) fractures in older people. The objective of this study was to assess the skeletal muscle fiber characteristics in elderly female hip fracture patients. Method Percutaneous needle biopsies were collected from the vastus lateralis muscle in 15 healthy young women (20 ± 0.4 years), 15 healthy elderly women (79 ± 1.7 years), and 15 elderly women with a fall-related hip fracture (82 ± 1.5 years). Immunohistochemical analyses were performed to assess Type I and Type II muscle fiber size, and myonuclear and satellite cell content. Results Type II muscle fiber size was significantly different between all groups (p < .05), with smaller Type II musclefibers in the hip fracture patients (2,609 ± 185 μm 2) compared with healthy elderly group (3,723 ± 322 μm 2) and the largest Type II muscle fibers in the healthy young group (4,755 ± 335 μm 2). Furthermore, Type I muscle fiber size was significantly lower in the hip fracture patients (4,684 ± 211 μm 2) compared with the healthy elderly group (5,842 ± 316 μm 2, p =.02). The number of myonuclei per Type II muscle fiber was significantly lower in the healthy elderly and hip fracture group compared with the healthy young group (p =.011 and p =.002, respectively). Muscle fiber satellite cell content did not differ between groups. Conclusion Elderly female hip fracture patients show extensive Type II muscle fiber atrophy when compared with healthy young or age-matched healthy elderly controls. Type II muscle fiber atrophy is an important hallmark of sarcopenia and may predispose to falls and (hip) fractures inthe older population

Prolonged leucine supplementation does not augment muscle mass or affect glycemic control in elderly type 2 diabetic men

The loss of muscle mass with aging has been, at least partly, attributed to a blunted muscle protein synthetic response to food intake. Leucine coingestion has been reported to stimulate postprandial insulin release and augment postprandial muscle protein accretion. We assessed the clinical benefits of 6 mo of leucine supplementation in elderly, type 2 diabetes patients. Sixty elderly males with type 2 diabetes ( age, 71 ± 1 y; BMI, 27.3 ± 0.4 kg/m2 ) were administered 2.5 g L-leucine ( n = 30 ) or a placebo ( n = 30 ) with each main meal during 6 mo of nutritional intervention ( 7.5 g/d leucine or placebo ). Body composition, muscle fiber characteristics, muscle strength, glucose homeostasis, and basal plasma amino acid and lipid concentrations were assessed prior to, during, and after intervention. Lean tissue mass did not change or differ between groups and at 0, 3, and 6 mo were 61.9 ± 1.1, 62.2 ± 1.1, and 62.0 ± 1.0 kg, respectively, in the leucine group and 62.2 ± 1.3, 62.2 ± 1.3, and 62.2 ± 1.3 kg in the placebo group. There also were no changes in body fat percentage, muscle strength, and muscle fiber type characteristics. Blood glycosylated hemoglobin did not change or differ between groups and was 7.1 ± 0.1% in the leucine group and 7.2 ± 0.2% in the placebo group. Consistent with this, oral glucose insulin sensitivity and plasma lipid concentrations did not change or differ between groups. We conclude that prolonged leucine supplementation ( 7.5 g/d ) does not modulate body composition, muscle mass, strength, glycemic control, and/or lipidemia in elderly, type 2 diabetes patients who habitually consume adequate dietary protein

Protein supplementation during resistance-type exercise training in the elderly

LEENDERS, M., L. B. VERDIJK, L. VAN DER HOEVEN, J. VAN KRANENBURG, R. NILWIK, W. K. W. H. WODZIG, J. M. G. SENDEN, H. A. KEIZER, and L. J. C. VAN LOON. Protien Supplementation during Resistance-Type Exercise Training in the Elderly. Med. Sci. Sports Exerc., Vol. 45, No. 3, pp. 542–552, 2013. Introduction: Resistance training has been well established as an effective treatment strategy to increase skeletal muscle mass and strength in the elderly. We assessed whether dietary protein supplementation can further augment the adaptive response to prolonged resistance-type exercise training in healthy elderly men and women. Methods: Healthy elderly men (n = 31, 70 T 1 yr) and women (n = 29, 70 T 1 yr) were randomly assigned to a progressive, 24-wk resistance-type exercise training program with or without additional protein supplementation (15 gIdj1 ). Muscle hypertrophy was assessed on a wholebody Dual-energy X-ray absorptiometry (DXA), limb (computed tomography), and muscle fiber (biopsy) level. Strength was assessed regularly by 1-repetition maximum (RM) strength testing. Functional capacity was assessed with a sit-to-stand and handgrip test. Results: One-RM strength increased by 45% T 6% versus 40% T 3% (women) and 41% T 4% versus 44% T 3% (men) in the placebo versus protein group, respectively (P G 0.001), with no differences between groups. Leg muscle mass (women, 4% T 1% vs 3% T 1%; men, 3% T 1% vs 3% T 1%) and quadriceps cross-sectional area (women, 9% T 1% vs 9% T 1%; men, 9% T 1% vs 10% T 1%) increased similarly in the placebo versus protein groups (P G 0.001). Type II muscle fiber size increased over time in both placebo and protein groups (25% T 13% vs 30% T 9% and 23% T 12% vs 22% T 10% in the women and men, respectively). Sit-to-stand improved by 18% T 2% and 19% T 2% in women and men, respectively (P G 0.001). Conclusion: Prolonged resistance-type exercise training increases skeletal muscle mass and strength, augments functional capacity, improves glycemia and lipidemia, and reduces blood pressure in healthy elderly men and women. Additional protein supplementation (15 gIdj1 ) does not further increase muscle mass, strength, and/or functional capacit

Protein Supplementation during Resistance-Type Exercise Training in the Elderly

LEENDERS, M., L. B. VERDIJK, L. VAN DER HOEVEN, J. VAN KRANENBURG, R. NILWIK, W. K. W. H. WODZIG, J. M. G. SENDEN, H. A. KEIZER, and L. J. C. VAN LOON. Protien Supplementation during Resistance-Type Exercise Training in the Elderly. Med. Sci. Sports Exerc., Vol. 45, No. 3, pp. 542–552, 2013. Introduction: Resistance training has been well established as an effective treatment strategy to increase skeletal muscle mass and strength in the elderly. We assessed whether dietary protein supplementation can further augment the adaptive response to prolonged resistance-type exercise training in healthy elderly men and women. Methods: Healthy elderly men (n = 31, 70 T 1 yr) and women (n = 29, 70 T 1 yr) were randomly assigned to a progressive, 24-wk resistance-type exercise training program with or without additional protein supplementation (15 gIdj1 ). Muscle hypertrophy was assessed on a wholebody Dual-energy X-ray absorptiometry (DXA), limb (computed tomography), and muscle fiber (biopsy) level. Strength was assessed regularly by 1-repetition maximum (RM) strength testing. Functional capacity was assessed with a sit-to-stand and handgrip test. Results: One-RM strength increased by 45% T 6% versus 40% T 3% (women) and 41% T 4% versus 44% T 3% (men) in the placebo versus protein group, respectively (P G 0.001), with no differences between groups. Leg muscle mass (women, 4% T 1% vs 3% T 1%; men, 3% T 1% vs 3% T 1%) and quadriceps cross-sectional area (women, 9% T 1% vs 9% T 1%; men, 9% T 1% vs 10% T 1%) increased similarly in the placebo versus protein groups (P G 0.001). Type II muscle fiber size increased over time in both placebo and protein groups (25% T 13% vs 30% T 9% and 23% T 12% vs 22% T 10% in the women and men, respectively). Sit-to-stand improved by 18% T 2% and 19% T 2% in women and men, respectively (P G 0.001). Conclusion: Prolonged resistance-type exercise training increases skeletal muscle mass and strength, augments functional capacity, improves glycemia and lipidemia, and reduces blood pressure in healthy elderly men and women. Additional protein supplementation (15 gIdj1 ) does not further increase muscle mass, strength, and/or functional capacit