Purpose: To examine the relationship between the maximal power output (MPO) in an individualized 7 × 2-minute incremental (INCR) test, average power in a 2k (W2k) rowing ergometer test, and maximal oxygen uptake () and to develop a regression equation to predict . Methods: A total of 34 male club rowers (age 18–30 y) performed a 2k and an INCR test in a Concept2 rowing ergometer to determine and compare MPO, W2k, and . Results: No significant difference was found between measured during INCR or 2k test (P = .73). A very high correlation coefficient (r = .96) was found between MPO and and between W2k and (r = .93). Linear regression analyses were developed for predicting from MPO: (1)  (mL·min−1) = 11.49 × MPO + 810 and from W2k: (2)  = 10.96 × W2k + 1168. Cross-validation analyses were performed using an independent sample of 14 rowers. There was no difference between the mean predicted in the INCR test (4.41 L·min−1) or the 2k test (4.39 L·min−1) and the observed (4.40 L·min−1). Technical error of measurement was 3.1% and 3.6%, standard error of estimate was 0.136 and 0.157 mL·min−1, and validation coefficients (r) were .95 and .94 using Equation (1) and (2), respectively. Conclusion: A prediction model only including MPO or W2k explains 88% to 90% of the variability in and is suggested for practical use in male club rowers.

This paper aimed to examine the acute effect of low-load (LL) exercise with blood-flow restriction (LL-BFR) on microvascular oxygenation and muscle excitability of the vastus medialis (VM) and vastus lateralis (VL) muscles during a single bout of unilateral knee extension exercise performed to task failure. Seventeen healthy recreationally resistance-trained males were enrolled in a within-group randomized cross-over study design.Participants performed one set of unilateral knee extensions at 20% of one-repetition maximum (1RM) to task failure, using a LL-BFR or LL free-flow (LL-FF) protocol in a randomized order on separate days. Changes in oxygenation and muscle excitability in VL and VM were assessed using near-infrared spectroscopy (NIRS) and surface electromyography (sEMG), respectively. Pain measures were collected using the visual analog scale (VAS) before and following set completion. Within-and between-protocol comparisons were performed at multiple time points of set completion for each muscle. During LL-BFR, participants performed 43% fewer repetitions and reported feeling more pain compared to LL-FF (p<0.05). Normalized to time to task failure, LL-BFR and LL-FF generally demonstrated similar progression in microvascular oxygenation and muscle excitability during exercise to task failure. The present results demonstrate that LL-BFR accelerates time to task failure, compared with LL-FF, resulting in a lower dose of mechanical work to elicit similar levels of oxygenation, blood-pooling, and muscle excitability. LL-BFR may be preferable to LL-FF in clinical settings where high workloads are contraindicated, although increased pain experienced during BFR may limit its application.

Background Bariatric surgery has adverse effects on the muscular-skeletal system with loss of bone mass and muscle mass and an increase in the risk of fracture. Zoledronic acid is widely used in osteoporosis and prevents bone loss and fracture. Bisphosphonates may also have positive effects on skeletal muscle. The aim of this study is to investigate the effects of zoledronic acid for the prevention of bone and muscle loss after bariatric surgery.  Methods/design This is a randomized double-blind placebo-controlled study. Sixty women and men with obesity aged 35 years or older will complete baseline assessments before randomization to either zoledronic acid (5 mg in 100 ml isotonic saline) or placebo (100 ml isotonic saline only) 3 weeks before surgery with Roux-en-Y-gastric bypass (RYGB) or sleeve gastrectomy (SG). Follow-up assessments are performed 12 and 24 months after surgery. The primary outcome is changes in lumbar spine volumetric bone mineral density (vBMD) assessed by quantitative computed tomography (QCT). Secondary bone outcomes are changes in proximal femur vBMD assessed by QCT. Changes in cortical and trabecular bone microarchitecture and estimated bone strength will be assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Cortical material bone strength at the mid-tibia diaphysis will be assessed using microindentation and fasting blood samples will be obtained to assess biochemical markers of bone turnover and calcium metabolism.  Secondary muscle outcomes include whole body lean mass assessed using dual-energy X-ray absorptiometry. Dynamometers will be used to assess handgrip, shoulder, ankle, and knee muscle strength. Short Physical Performance Battery, 7.6-m walking tests, 2-min walking test, and a stair climb test will be assessed as biomarkers of physical function. Self-reported physical activity level is assessed using International Physical Activity Questionnaire (IPAQ). Discussion Results from this study will be instrumental for the evidence-based care of patients undergoing bariatric surgery. Trial registration ClinicalTrials.gov NCT04742010. Registered on 5 February 2021.

Background: Laboratory assessment of maximal oxygen uptake () is physically and mentally draining for the athlete and requires expensive laboratory equipment. Indirect measurement of could provide a practical alternative to laboratory testing. Purpose: To examine the relationship between the maximal power output (MPO) in an individualized 7 × 2-minute incremental test (INCR-test) and and to develop a regression equation to predict from MPO in female rowers. Methods: Twenty female club and Olympic rowers (development group) performed the INCR-test on a Concept2 rowing ergometer to determine and MPO. A linear regression analysis was used to develop a prediction of from MPO. Cross-validation analysis of the prediction equation was performed using an independent sample of 10 female rowers (validation group). Results: A high correlation coefficient (r = .94) was found between MPO and . The following prediction equation was developed: (mL·min−1) = 9.58 × MPO (W) + 958. No difference was found between the mean predicted in the INCR-test (3480 mL·min−1) and the measured (3530 mL·min−1). The standard error of estimate was 162 mL·min−1, and the percentage standard error of estimate was 4.6%. The prediction model only including MPO, determined during the INCR-test, explained 89% of the variability in . Conclusion: The INCR-test is a practical and accessible alternative to laboratory testing of .

BackgroundBariatric surgery has adverse effects in the muscular-skeletal system with loss of bone mass and muscle mass and an increase in the risk of fracture. Zoledronic acid is widely used in osteoporosis and prevents bone loss and fracture. Bisphosphonates may also have positive effects in skeletal muscle. The aim of this study is to investigate the effects of zoledronic acid for the prevention of bone and muscle loss after bariatric surgery.Methods/designThis is a randomized double-blind placebo-controlled study. Sixty women and men with obesity aged 35 years or older will complete baseline assessments before randomization to either zoledronic acid (5 mg in 100 ml isotonic saline) or placebo (100 ml isotonic saline only) three weeks before surgery with Roux-en-Y-gastric bypass (RYGB) or sleeve gastrectomy (SG). Follow-up assessments are performed 12 and 24 months after surgery. The primary outcome is changes in lumbar spine volumetric bone mineral density (vBMD) assessed by quantitative computed tomography (QCT). Secondary bone outcomes are changes in proximal femur vBMD assessed by QCT. Changes in cortical and trabecular bone microarchitecture and estimated bone strength will be assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Cortical material bone strength at the mid-tibia diaphysis will be assessed using microindentation and fasting blood samples will be obtained to assess biochemical markers of bone turnover and calcium metabolism. Secondary muscle outcomes include whole body lean mass assessed using dual-energy X-ray absorptiometry. Dynamometers will be used to assess handgrip, shoulder, ankle, and knee muscle strength. Short Physical Performance Battery, 7.6-meter walking tests, 2-minute walking test and a stair climb test will be assessed as biomarkers of physical function. Self-reported physical activity level is assessed using International Physical Activity Questionnaire (IPAQ).DiscussionResults from this study will be instrumental for the evidence-based care of patients undergoing bariatric surgery.Trial registrationClinicalTrials.gov, ID: NCT04742010. Registered February 5th 2021.

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Walking is the most democratic model of physical activity and recent evidence has considered the use of interval walking as a type of effort in clinical populations. However, studies on its acute effects on cardiac and metabolic parameters are scarce. PURPOSE: To measure and compare the effects of two bouts of walking (continuous or interval) on blood pressure, heart rate, oxygen consumption, lactate and glucose in elderly women. METHODS: Thirty elderly women (67.8±3.8 yo) were exposure to i) Maximal walking speed (MWS) test, and ii) Two walking training sessions, randomly determined: Continuous walking (CW: 30 min at 75% of MWS) and Intermittent walking (IW: 5 x 3min at 95% MWS : 3 min at 55% MWS). Blood pressure (BP), heart rate (HR), blood lactate (Lac) and glucose (Glu) were measured before and after each training session, and oxygen consumption (VO2) was collected during whole sessions. Data analysis was conducted using descriptive statistics and multivariate analyses of variance with repeated measures. RESULTS: Were found effects of moment (pre-versus post-training) for systolic (114.7±15.22 to 126.38±18.83 mmHg, p < 0.001) and diastolic (66.8±10.5 to 70.4±9.7 mmHg, p < 0.05) blood pressure, double product (8,097±1,576 to 14,353±2,840 mmHg•HR, p < 0.001) and glucose (138.6±54.5 to 109.1±39.9 md/dL, p < 0.05) with no differences between sessions. Interactions were found for double product and lactate concentration. Differences between sessions were found for HR peak (CW: 108.7±13.1 bpm, IW: 120.6±16.1 bpm; p = 0.003), %HRmax (CW: 67.7±7.9 %HRmax, IW: 75.2±10.1 %HRmax; p = 0.002), and VO2 peak (CW: 17.8±3.8 mL/kg/min, IW: 21.0±3.5 mL/kg/min; p = 0.001). Pre-post training differences between sessions were found for double product (CW: 5,444±1,744 mmHg•HR, IW: 7,066±2,601 mmHg•HR; p = 0.005) and lactate (CW: -0.08±1.6 mmol, IW: 0.79±1.1 mmol; p = 0.017). CONCLUSIONS: Mainly, both sessions reduced blood glucose from high levels to normal range and increased slightly hemodynamic variables. IW showed higher increases in heart rate (absolute and relative to HRmax), VO2 and blood lactate. CW and IW normalized blood glucose and IW elicited higher cardiorespiratory demand.

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