We characterized physical activity (PA) and its relation to physical function and number of comorbidities in people with diabetes and transtibial amputation (AMP), people with diabetes without AMP, and nondisabled adults without diabetes or AMP. Twenty-two individuals with type 2 diabetes mellitus (DM) and transtibial amputation (DM+AMP), 11 people with DM, and 13 nondisabled participants were recruited for this cross-sectional cohort study. Measures included PA volume and intensity, a Timed Up and Go test, a 2-min walk test, and number of comorbidities. The nondisabled group performed greater amounts of PA than the DM group, who performed greater amounts of PA than the DM+AMP group. PA was related to physical function in the DM group and in the DM+AMP group, whereas no such relationship existed in the nondisabled group. PA was not related to number of comorbidities in any group. These findings suggest the ability to walk may affect overall performance of PA. Alternately, PA may alleviate walking problems. This possibility is of interest because issues with walking may be modifiable by improved levels and intensity of PA. PA’s lack of relation to number of comorbidities suggests that factors beyond multiple morbidities account for group differences in PA.

In this study, we compared acute and chronic bone marker and hormone responses to 6 weeks of low intensity (20% 1RM) blood flow restriction (BFR20) resistance training to high intensity (70% 1RM) traditional resistance training (TR70) and moderate intensity (45% 1RM) traditional resistance training (TR45) in young men (18–35 years). Participants were randomized to one of the training groups or to a control group (CON). The following training programs were performed 3 days per week for 6 weeks for knee extension and knee flexion exercises: BFR20, 20%1RM, 4 sets (30, 15, 15, 15 reps) wearing blood flow restriction cuffs around the proximal thighs; TR70, 70% 1RM 3 sets 10 reps; and TR45, 45% 1RM 3 sets 15 reps. Muscle strength and thigh cross-sectional area were assessed at baseline, between week 3 and 6 of training. Acute bone marker (Bone ALP, CTX-I) and hormone (testosterone, IGF-1, IGFBP-3, cortisol) responses were assessed at weeks 1 and 6, with blood collection done in the morning after an overnight fast. The main findings were that the acute bone formation marker (Bone ALP) showed significant changes for TR70 and BFR20 but there was no difference between weeks 1 and 6. TR70 had acute increases in testosterone, IGF-1, and IGFBP-3 (weeks 1 and 6). BFR20 had significant acute increases in testosterone (weeks 1 and 6) and in IGF-1 at week 6, while TR45 had significant acute increases in testosterone (week 1), IGF-1 (week 6), and IGFBP-3 (week 6). Strength and muscle size gains were similar for the training groups. In conclusion, low intensity BFR resistance training was effective for stimulating acute bone formation marker and hormone responses, although TR70 showed the more consistent hormone responses than the other training groups.

Rock climbing is rapidly increasing in popularity as a recreational activity and as a competitive sport. Few studies have tested acute physiological responses to climbing, and no studies to date have tested hormone responses to a climbing-based workout. This study aimed to measure testosterone (T), growth hormone (GH), and cortisol (C) responses to continuous vertical climbing in young male rock climbers. Ten male rock climbers, aged between 21 and 30 years, climbed laps on a submaximal 55' climbing route for 30 min, or until exhaustion, whichever came first. Heart rate (HR) was recorded after every lap. Blood samples were collected by venipuncture before (Pre), immediately post (IP), and 15 min after the climbing exercise (P15) to assess blood lactate and plasma GH, T, and C. Subjects climbed 24.9 ± 1.9 min and 507.5 ± 82.5 feet. Peak HR was 182.1 ± 2.3 bpm, and lactate (Pre: 2.9 ± 0.6 mmol/dL, IP: 11.1 ± 1.0 mmol/dL) significantly (P < 0.05) increased from Pre to IP. T concentrations significantly (P < 0.05) increased from Pre (6.04 ± 0.31 ng/mL) to IP (7.39 ± 0.40 ng/mL) and returned to baseline at P15 (6.23 ± 0.33 ng/mL). Cortisol levels did not significantly change during the protocol. GH significantly (P < 0.01) increased from Pre (0.63 ± 0.17 ng/mL) to IP (19.89 ± 4.53 ng/mL) and remained elevated at P15 (15.03 ± 3.89 ng/mL). An acute, short-term bout of high-intensity continuous climbing was an effective exercise stimulus for elevating plasma testosterone and growth hormone levels in young males.

Supervised strength training represents an efficacious intervention for improving strength in older adults with residual benefits lasting longer than previously expected.

Objective To examine differences between the affected and sound limbs in ankle-foot orthosis (AFO)-using survivors of stroke. AFOs and gait aids are commonly used to allow survivors of stroke to ambulate. Previous investigations of bone mineral density (BMD) in stroke survivors cite gait aid use, but have not controlled for their use when presenting outcomes. Design Observational study. Setting University of Oklahoma Bone Density laboratory. Participants Nine ambulatory, AFO-using survivors of stroke (ages 55-74 years, 13.5±4.4 years post-stroke, 6.5±1.4 years of AFO use). Interventions Not applicable. Main Outcome Measures Total body and hip areal BMD (aBMD) and bone mineral content (BMC) were assessed by DXA. The 4%, 38% and 66% sites of both tibiae were measured with peripheral Quantitative Computed Tomography (pQCT) for total, cortical and trabecular volumetric BMD (vBMD) and BMC. Bone geometry, bone strength index (BSI), strength strain index (SSI) and moments of inertia (Imin, Imax) were determined. Results Total hip and trochanter BMC and aBMD were 7%-19% greater on the sound side (p<0.05). Total BMC and vBMD were 2%-21% (p<0.05) on the sound limb, depending on site. Trabecular BMC and vBMD and BSI values were 19%, 21%, and 31% higher (p<0.05) on sound limb at the 4% site. Cortical BMC and vBMD (p<0.05), and cortical thickness (p<0.01) were greater on the sound side at the 38% and 66% sites. Cortical area and bone strength (SSI, Imin) were greater (p<0.05) at the 66% site. Endosteal circumferences were greater on the affected side (p<0.01). Conclusion Interlimb differences in bone characteristics following a stroke persist despite returning to ambulatory status with AFO use.