Determinants of V̇+O2peak Changes After Aerobic Training in Coronary Heart Disease Patients.

This study aimed to highlight the ventilatory and circulatory determinants of changes in ˙VO2peak after exercise-based cardiac rehabilitation (ECR) in patients with coronary heart disease (CHD). Eighty-two CHD patients performed, before and after a 3-month ECR, a cardiopulmonary exercise testing (CPET) on a bike with gas exchanges measurements (˙VO2peak, minute ventilation, i. e., ˙VE), and cardiac output (Q˙c). The arteriovenous difference in O2 (C(a-v¯)O2) and the alveolar capillary gradient in O2 (PAi-aO2) were calculated using Fick's laws. Oxygen uptake efficiency slope (OUES) was calculated. A 5.0% cut off was applied for differentiating non- (NR: ˙VO2<0.0%), low (LR: 0.0≤ ∆˙VO2<5.0%), moderate (MR: 5.0≤∆˙VO2 < 10.0%), and high responders (HR: ∆˙VO2≥10.0%) to ECR. A total of 44% of patients were HR (n=36), 20% MR (n=16), 23% LR (n=19), and 13% NR (n=11). For HR, the ˙VO2peak increase (p<0.01) was associated with increases in ˙VE (+12.8±13.0 L/min, p<0.01), (+1.0±0.9 L/min, p<0.01), and C(a-v¯)O2 (+2.3±2.5 mLO2/100 mL, p<0.01). MR patients were characterized by+6.7±19.7 L/min increase in ˙VE (p=0.04) and+0.7±1.0 L/min of Q˙c (p<0.01). ECR induced decreases in ˙VE (p=0.04) and C(a-v¯)O2 (p<0.01) and a Q˙c increase in LR and NR patients (p<0.01). Peripheral and ventilatory responses more than central adaptations could be responsible for the ˙VO2peak change with ECR in CHD patients.

Benefits of a Supervised Ambulatory Outpatient Program in a Cardiovascular Rehabilitation Unit Prior to a Heart Transplant: A Case Study.

Preoperative peak oxygen uptake ( V . O2peak ) and ventilatory efficiency ( V . E / V . CO2slope) are related to the vital prognosis after cardiac transplantation (HTx). The objective of our study was to evaluate the effects of exercise-based cardiac rehabilitation (ECR) program on the preoperative exercise capacity of a HTx candidate. A male patient, aged 50-55 years, with chronic heart failure was placed on the HTx list and performed 12 weeks of intensive ECR (5 sessions-a-week). Our results showed that the cardiac index continuously increased between the onset and the end of ECR (1.40 vs. 2.53 L.min-1.m2). The first 20 sessions of ECR induced a V . O2peak increase (15.0 vs. 19.3 ml.min-1.kg-1, corresponding to 42.0 and 53.0% of its maximal predicted values, respectively). The peak V . O2 plateaued between the 20th and the 40th ECR session (19.3 vs. 19.4 ml.min-1.kg-1) then progressively increased until the 60th ECR session to reach 25.7 ml.min-1.kg-1, i.e., 71.0% of the maximal predicted values. The slope of V . E/ V . CO2 showed a biphasic response during the ECR program, with an increase between the onset and the 20th ECR session (58.02 vs. 70.48) and a decrease between the 20th and the 40th ECR session (70.48 vs. 40.94) to reach its minimal value at the 60th ECR session (31.97). After the first 40 sessions of the ECR program, the Seattle Heart Failure Model score predicted median survival time was estimated at 7.2 years. In conclusion, the improvement in exercise capacity and cardiorespiratory function following the ECR helped delay the heart transplant surgery in our patient awaiting heart transplantation.

Acute effects of aerobic continuous, intermittent, and resistance exercise on glycemia in adolescents males with type 1 diabetes.

OBJECTIVE: Increased levels of physical activity is often associated with reduced HbA1c in individuals with diabetes. However, the effect on glycemic control differs between different programs of exercise. The aim of this study was to compare the acute effects on glycemia of resistance and two aerobic continuous and intermittent exercise bouts in adolescent males with type 1 diabetes. RESEARCH DESIGN AND METHODS: Eight active males with type 1 diabetes (17.5 ± 0.8 years, BMI: 20.8 ± 2.2 kg/m2 , HbA1c: 7.2 ± 0.5% [54.9 ± 5.3 mmol/mol]) performed four experimental sessions-nonexercise (control), resistance exercise (RE) and two isocaloric continuous (CE) and intermittent (IE) cycling exercise trials-in a randomized order. Each session consisted of 45 min of exercise (except for the control modality) and 60 min of passive recovery. Venous blood was drawn for assessment of plasma glucose (PG). A two-way repeated-measures ANOVA was used for statistical comparisons. RESULTS: A significant time-to-exercise interaction effect on PG was detected. PG significantly decreased during IE (-5.1 ± 1.6 mmol/L) and CE (-5.4 ± 1.8 mmol/L) but not during RE (-1.0 ± 1.4 mmol/L, ns). Additionally, decreases in PG after IE and CE were sustained throughout the recovery period. CONCLUSIONS: While intermittent and continuous aerobic exercises are associated with a lowering of glycemia in male adolescents with type 1 diabetes, glycemia remained stable without significant alterations after resistance exercise. These findings hold important implications related to clinical exercise advice and disease management in adolescents with type 1 diabetes.

Post-exercise Heart Rate Variability: Whole-body Cryotherapy vs. Contrast Water Therapy.

High-intensity training sessions are known to alter cardiac autonomic modulation. The purpose of this study was to compare the effects of whole-body cryotherapy, contrast water therapy and passive recovery on the time course of cardiac autonomic markers following a standardized HIT session. Eleven runners completed a high intensity session followed by one of the following recovery interventions: whole-body cryotherapy, contrast water therapy or passive recovery. Changes in cardiac autonomic modulation were assessed in supine and standing positions during an active tilt test at pre-, post-14 h and post-38 h. In supine, high-frequency power increased from pre- to post-14 h following whole-body cryotherapy (1661.1±914.5 vs. 2799.0±948.4 ms2, respectively; p=0.023) and contrast water therapy (1906.1±1327.9 vs. 4174.3±2762.9 ms2, respectively; p=0.004) whereas high frequency power decreased in response to passive recovery (p=0.009). In standing, low-frequency power increased from pre-to post-38 h (1784.3 ± 953.7 vs. 3339.8±1862.7 ms2, respectively; p=0.017) leading to an increase in total power from pre- to post-38 h (1990.8 ± 1089.4 vs. 3606.1±1992.0 ms2, respectively; p=0.017). Spectral analysis revealed that contrast water therapy appears to be a more efficient recovery strategy than whole-body cryotherapy in restoring cardiac autonomic homeostasis.

Does the direct anterior approach allow earlier recovery of walking following total hip arthroplasty? A randomized prospective trial using accelerometry.

INTRODUCTION: In total hip arthroplasty (THA), the anterior approach is attractive, being intermuscular, with theoretic functional benefit. Such benefit has been frequently claimed, but there are few data from randomized comparative studies using more precise metrics than patient satisfaction. We therefore conducted a randomized trial comparing early functional results between anterior and posterior approaches on gait analysis and functional scores. HYPOTHESIS: The study hypothesis was that there is no difference between the two approaches in terms of early recovery of walking. MATERIALS AND METHOD: A single-center single-surgeon prospective randomized study was conducted between February 2017 and April 2018. Inclusion criteria comprised: age<85 years, body-mass index (BMI)<32, and hip osteoarthritis with indication for THA. Preoperatively, the 2 groups were comparable for age, gender, BMI, Charnley, Harris, Postel-Merle-d'Aubigné and Oxford-12 scores and locomotor parameters (triaxial acceleration, step regularity and walking power). Preoperative and 3-, 6- and 12-week assessment comprised triaxial acceleration in walking and Postel-Merle-d'Aubigné, Harris and Oxford SF-12 scores. RESULTS: One hundred patients were randomized to the anterior approach (AA: n=50) and posterior approach (PA: n=50) groups. Hospital stay was comparable between groups: PA, 2.8±1.78 days [range, 2.29-3.31 days]; AA, 2.84±1.25 days [range, 2.48-3.2 days] (p=0.8). Operative time was significantly longer in AA: 70.1±11 minutes vs. 56.7±11.79 (p<0.0001). There were no significant differences in locomotor parameters (p 0.122 to 0.987) or functional scores (p 0.052 to 0.968) over the 3-month follow-up. There was no difference in cup inclination: PA, 39.6±6.87° [range, 37.65-41.55°] vs. AA, 37.74±4.2° [range, 36.55-38.93°] (p=0.09). There were 8/50 cases (16%) of neurapraxia of the lateral cutaneous nerve of the thigh in the AA group; rates for other complications did not differ between groups. CONCLUSION: Early functional results and especially objective locomotor parameters following THA were comparable between anterior and posterior approaches at 3 to 12 weeks. The approach should be chosen according to the surgeon's experience. LEVEL OF EVIDENCE: II, low-power prospective randomized study.

Effects of a short-term interval aerobic training program with recovery bouts on vascular function in sedentary aged 70 or over: A randomized controlled trial.

BACKGROUND: Interval aerobic training programs with active recovery bouts (IATP-R) are reported as being more adapted to seniors while improving cardiorespiratory and endurance parameters. Report of benefits on vascular function is still limited. PURPOSE: To measure the impact of IATP-R on vascular function among seniors. METHODS: Sedentary volunteers (≥70 years of age) were randomly assigned to either IATP-R (n = 30) or control group (n = 30). The IATP-R consisted of 2 weekly sessions of 30-min (6 × 4-min at first ventilatory threshold (VT1) intensity + 1-min at 40% of VT1) cycling exercise over 9.5-week. Controls remained their sedentary life over the same period. In all participants, the endothelial function was measured by flow-mediated dilation (FMD) in brachial artery and arterial stiffness through the carotid/radial and carotid/femoral pulse wave velocity (PWV). Systolic (SBP) and diastolic blood pressure (DBP) were measured at baseline and 9.5 weeks later. RESULTS: Resulting from a planned interim analysis, IATP-R improved SBP (IATP-R: from 133.7 ± 9.8 to 122.6 ± 9.4 mmHg vs. Controls: from 128.9 ± 12.5 to 132.6 ± 14.7 mmHg), DBP (IATP-R: from 80.2 ± 7.0 to 74.1 ± 6.7 mmHg vs. Controls: from 77.1 ± 6.8 to 80.3 ± 7.5 mmHg), and FMD (IATP-R: from 6.7 ± 2.0 to 7.5 ± 2.7% vs. Controls: from 7.9 ± 2.7 to 7.5 ± 2.5%). No significant impact on PWV was measured. CONCLUSION: Although these findings resulted from an interim analysis, IATP-R might be effective in regulating BP and improving endothelial function among sedentary seniors.

Effects of a short-term Interval Aerobic Training Programme with active Recovery bouts (IATP-R) on cognitive and mental health, functional performance and quality of life: A randomised controlled trial in sedentary seniors.

BACKGROUND: Interval aerobic training programme with active recovery bouts (IATP-R) has shown to improve tolerance to IATP among seniors. However, data concerning its benefits for seniors' health are still limited. PURPOSE: The purpose of this study was to examine the effects of IATP-R on seniors' health status. METHODS: Sedentary volunteers (n = 60, aged ≥70 years) were randomly assigned to either IATP-R or maintained sedentary lifestyle for 9.5 weeks. IATP-R consisted of 30-minute cycling (6 × 4 minutes at first ventilatory threshold (VT1 ) intensity + 1 minute at 40% of VT1 ) twice a week. Cognitive and functional performances were assessed with the Trail Making Test (TMT-A; TMT-B); Paced Auditory Serial Addition Test (PASAT); Timed Up and Go (TUG) test; 6-Minute Walk Test (6-MWT); one-leg balance test; and the Short Physical Performance Battery (SPPB) tests, respectively. QoL and anxiety/depression status were measured by the Short Form-12 and the Goldberg's Scale, respectively. All participants were assessed at baseline and 9.5 weeks later. RESULTS: Compared to controls, IATP-R improved cognitive functions (TMT-A: +1.5% vs -21.5%; TMT-B: +0.9% vs -13.3%; PASAT: +1.4% vs -14.6%; semantic fluency: -1.1% vs +11.7%), functional performance (TUG: +5.4% vs -16.5%; 6-MWT: -3.2% vs +11.5%; SPPB: -3.2% vs +14.6%; One-leg balance: -16.3% vs +25.0%); QoL (physical health: -13.3% vs +23.1%; mental health: -7.1% vs +8.2%); and depressive symptoms (+26.3% vs -42.8%). Significant impacts were measured neither on letter modality of fluency tasks nor on anxiety score. CONCLUSION: These data showed that IATP-R is an effective training programme to improve functional and cognitive performances, mental health and well-being in sedentary seniors. Trial registration ClinicalTrials.gov NCT02263573. Registered October 1, 2014.

Effects of Interval Aerobic Training Program with Recovery bouts on cardiorespiratory and endurance fitness in seniors.

Interval aerobic training programs (IATP) improve cardiorespiratory and endurance parameters. They are, however, unsuitable to seniors as frequently associated with occurrence of exhaustion and muscle pain. The purpose of this study was to measure the benefits of an IATP designed with recovery bouts (IATP-R) in terms of cardiorespiratory and endurance parameters and its acceptability among seniors (≥70 years). Sedentary healthy volunteers were randomly assigned either to IATP-R or sedentary lifestyle. All participants performed an incremental cycle exercise and 6-minute walk test (6-MWT) at baseline and 9.5 weeks later. The first ventilatory threshold (VT1 ); maximal tolerated power (MTP); peak of oxygen uptake (VO2peak ); maximal heart rate (HRmax ); and distance walked at 6-MWT were thus measured. IATP-R consisted of 19 sessions of 30-minute (6 × 4-min at VT1  + 1-minute at 40% of VT1 ) cycling exercise over 9.5 weeks. With an adherence rate of 94.7% without any significant adverse events, 9.5 weeks of IATP-R, compared to controls, enhanced endurance (VT1 : +18.3 vs -4.6%; HR at baseline VT1 : -5.9 vs +0.2%) and cardiorespiratory parameters (VO2peak : +14.1 vs -2.7%; HRmax : +1.6 vs -1.7%; MTP: +19.2 vs -2.3%). The walk distance at the 6-MWT was also significantly lengthened (+11.6 vs. -3.1%). While these findings resulted from an interim analysis planned when 30 volunteers were enrolled in both groups, IATP-R appeared as effective, safe, and applicable among sedentary healthy seniors. These characteristics are decisive for exercise training prescription and adherence.

Hydration: The New FIFA World Cup's Challenge for Referee Decision Making?

Various continental sporting events have exposed team sports referees to different environmental conditions. Several studies have focused on strategies to prevent athlete performance impairment induced by heat or warm (or both) conditions, but few authors have investigated the effect of heat on referees' performance. In a thermoneutral environment, referees' physical activity induced mild 2.0% dehydration, which was responsible for reductions in physical, psychomotor, and cognitive performances. Therefore, the hydration status of referees should be taken into account to reduce referees' errors and misjudgments in the heat.

Relevance of Damped Harmonic Oscillation for Modeling the Training Effects on Daily Physical Performance Capacity in Team Sport.

CONTEXT: Positive and negative effects of training induce apparent oscillations of performance, suggesting that the delayed cumulative effects of training on daily performance capacity (DPC) are best fitted by sine waves damped over time. PURPOSE: To compare the criterion validity of the impulse-response (IR) model of Banister et al and the damped harmonic oscillation (DHO) model for quantifying the training load (TL)-DPC relationship. METHODS: Six female professional volleyball players (20.8 ± 2.4 y) were monitored using the session rating of perceived exertion (sRPE) for 9 mo to quantify TL. Countermovement-jump (CMJ) and 4-step-approach-CMJ (4sCMJ) performances were recorded once a month. Parameters of models were determined by minimizing residual-sum squares between predicted and real performances with a nonlinear regression. RESULTS: DPC was best fitted by the DHO model rather than the IR model (CMJ, R2 = .80 ±.08 and.69 ±.20, respectively; 4sCMJ, R2 = .86 ± .09 and .67 ± .29, respectively). The damping parameter θ and the period T were positively correlated with age (ρ = 0.81, P < .05, and ρ = 0.86, P < .02, respectively). CONCLUSIONS: The DHO model is a useful tool for modeling DPC as the sum of the delayed DPCs from the consecutive training and recovery days. DPC could be considered the expression of the individual process of accumulation and dissipation of fatigue induced by training. DHO-model parameters were correlated with age, which prompts one to postulate that expertise has a major influence on DPC. The DHO model will help coaches develop a greater understanding of training effects and make monitoring of the training process more effective.

Effects of pre-exercise alkalosis on the decrease in VO2 at the end of all-out exercise.

PURPOSE: This study determined the effects of pre-exercise sodium bicarbonate ingestion (ALK) on changes in oxygen uptake (VO2) at the end of a supramaximal exercise test (SXT). METHODS: Eleven well-trained cyclists completed a 70-s all-out cycling effort, in double-blind trials, after oral ingestion of either 0.3 g kg(-1) of sodium bicarbonate (NaHCO3) or 0.2 g kg(-1) body mass of calcium carbonate (PLA). Blood samples were taken to assess changes in acid-base balance before the start of the supramaximal exercise, and 0, 5 and 8 min after the exercise; ventilatory parameters were also measured at rest and during the SXT. RESULTS: At the end of the PLA trial, which induced mild acidosis (blood pH = 7.20), subjects presented a significant decrease in VO2 (P < 0.05), which was related to the amplitude of the decrease in minute ventilation (VE) during the SXT (r = 0.70, P < 0.01, n = 11). Pre-exercise metabolic alkalosis significantly prevented the exercise-induced decrease in VO2 in eleven well-trained participants (PLA:12.5 ± 2.1 % and ALK: 4.9 ± 0.9 %, P < 0.05) and the decrease in mean power output was significantly less pronounced in ALK (P < 0.05). Changes in the VO2 decrease between PLA and ALK trials were positively related to changes in the VE decrease (r = 0.74, P < 0.001), but not to changes in power output (P > 0.05). CONCLUSIONS: Pre-exercise alkalosis counteracted the VO2 decrease related to mild acidosis, potentially as a result of changes in VE and in muscle acid-base status during the all-out supramaximal exercise.

Effects of modified multistage field test on performance and physiological responses in wheelchair basketball players.

A bioenergetical analysis of manoeuvrability and agility performance for wheelchair players is inexistent. It was aimed at comparing the physiological responses and performance obtained from the octagon multistage field test (MFT) and the modified condition in "8 form" (MFT-8). Sixteen trained wheelchair basketball players performed both tests in randomized condition. The levels performed (end-test score), peak values of oxygen uptake (VO2peak), minute ventilation (VEpeak), heart rate (HRpeak), peak and relative blood lactate (Δ[Lact(-)] = peak--rest values), and the perceived rating exertion (RPE) were measured. MFT-8 induced higher VO2peak and VEpeak values compared to MFT (VO2peak: 2.5 ± 0.6 versus 2.3 ± 0.6 L · min(-1) and VEpeak: 96.3 ± 29.1 versus 86.6 ± 23.4 L · min(-1); P < 0.05) with no difference in other parameters. Significant relations between VEpeak and end-test score were correlated for both field tests (P < 0.05). At exhaustion, MFT attained incompletely VO2peak and VEpeak. Among experienced wheelchair players, MFT-8 had no effect on test performance but generates higher physiological responses than MFT. It could be explained by demands of wheelchair skills occurring in 8 form during the modified condition.

Comparison Between 30-15 Intermittent Fitness Test and Multistage Field Test on Physiological Responses in Wheelchair Basketball Players.

The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT) and the 30-15 intermittent field test (30-15IFT). Eighteen trained wheelchair basketball players (WBP) (WBP: 32.0 ± 5.7 y, IWBF classification: 2.9 ± 1.1 points) performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV), VO2peak and the peak values of minute ventilation (V Epeak), respiratory frequency (RF) and heart rate (HRpeak) were measured throughout both tests; peak and net blood lactate (Δ[Lact(-)] = peak-rest values) and perceived rating exertion (RPE) values at the end of each exercise. No significant difference in VO2peak, VEpeak, and RF was found between both tests. 30-15IFT was shorter (12.4 ± 2.4 vs. 14.9 ± 5.1 min, P < 0.05) but induced higher values of MRV and Δ[Lact(-)] compared to MFT (14.2 ± 1.8 vs. 11.1 ± 1.9 km·h(-1) and 8.3 ± 4.2 vs. 6.9 ± 3.3 mmol·L(-1), P < 0.05). However, HRpeak and RPE values were higher during MFT than 30-15IFT(172.8 ± 14.0 vs. 166.8 ± 13.8 bpm and 15.3 ± 3.8 vs.13.8 ± 3.5, respectively, P < 0.05). The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP.

Effects of sports drinks on the maintenance of physical performance during 3 tennis matches: a randomized controlled study.

BACKGROUND: Tennis tournaments often involve playing several consecutive matches interspersed with short periods of recovery. OBJECTIVE: The objective of this study was firstly to assess the impact of several successive tennis matches on the physical performance of competitive players and secondly to evaluate the potential of sports drinks to minimize the fatigue induced by repeated matches. METHODS: This was a crossover, randomized controlled study. Eight male regionally-ranked tennis players participated in this study. Players underwent a series of physical tests to assess their strength, speed, power and endurance following the completion of three tennis matches each of two hours duration played over three consecutive half-days (1.5 day period for each condition). In the first condition the players consumed a sports drink before, during and after each match; in the second, they drank an identical volume of placebo water. The results obtained were compared with the third 'rest' condition in which the subjects did not play any tennis. Main outcomes measured were maximal isometric strength and fatigability of knee and elbow extensors, 20-m sprint speed, jumping height, specific repeated sprint ability test and hand grip strength. RESULTS: The physical test results for the lower limbs showed no significant differences between the three conditions. Conversely, on the upper limbs the EMG data showed greater fatigue of the triceps brachii in the placebo condition compared to the rest condition, while the ingestion of sports drinks attenuated this fatigue. CONCLUSIONS: This study has demonstrated for the first time that, when tennis players are adequately hydrated and ingest balanced meals between matches, then no large drop in physical performance is observed even during consecutive competitive matches. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01353872.

Effects of pre-exercise, endurance, and recovery designer sports drinks on performance during tennis tournament simulation.

Sports drinks are often used before, during, and after tennis tournaments, but their ability to influence physiological and psychological variables and the characteristics of tennis match play remains uncertain. The objective of this study was to evaluate the impact of ingesting specially formulated pre-exercise, endurance, and recovery sports drinks on glycemia and performance indices during a simulated tennis tournament. Eight well-trained male tennis players performed two 3-match round-robin tennis tournaments although ingesting sports drinks (SPDs) or placebos (PLAs) before, during, and after each match (crossover study design). Before the first tournament, match and drink order were randomized (SPDs or PLAs first) and players were placed under controlled nutritional and hydration conditions. Glycemia, heart rate response, rate of perceived exertion, and notational/match analysis were assessed during each match. Sports drinks maintained higher glycemia levels during match 2 and 3 of the tennis tournament compared with PLAs (p < 0.01). Moreover, higher mean heart rates (p < 0.01) and stroke frequencies (p < 0.01) concomitantly with lower rates of perceived exertion (p < 0.01) were recorded throughout the duration of the tournament, when players used the SPDs. During a 3-match tennis tournament, SPDs allow higher stroke frequency during play, with decreased rates of perceived exertion.