Nieto-Jimenez, C., School of Physical Therapy, University Andres Bello, Viña del mar, Chile.
Naranjo-Orellana, J., Medina-Porcile, C.L., Gawn, J., et al

Physiol Int 2026

BACKGROUND: Ventilatory thresholds (VT1 and VT2) determined from gas-exchange criteria during cardiopulmonary exercise testing (CPET) provide reference points for exercise-intensity prescription, but their routine use is limited in applied settings. Detrended fluctuation analysis alpha 1 (DFA-alpha1) has emerged as a potential non-invasive marker of physiological transitions during exercise.
OBJECTIVE: To quantify and compare DFA-alpha1 values against CPET-derived ventilatory thresholds and between exercise modes during constant-load swimming, cycling, and running in trained triathletes.
METHODS: Seventeen triathletes (13 men, 4 women) completed maximal incremental CPETs in swimming, cycling, and running, after which constant-load trials were undertaken at VT1 and VT2, as determined from CPET using standard ventilatory criteria. R-R intervals were recorded with a Polar V800 and Polar H10 and processed in Kubios HRV Scientific v4.2.0. DFA-alpha1 was calculated using a 120-s moving window with 5-s updates. Between-modality comparisons were performed using repeated-measures ANOVA.
RESULTS: At VT1, V O2, heart rate, and PetCO2 differed by modality, whereas DFA-alpha1 did not differ significantly between swimming, cycling, and running (0.74 +/- 0.30, 0.75 +/- 0.21, and 0.65 +/- 0.20, respectively; P = 0.456). At VT2, V O2 and heart rate again differed by modality, whereas DFA-alpha1 showed no significant differences between modalities but wide between participant variability (0.42 +/- 0.13, 0.37 +/- 0.11, and 0.47 +/- 0.13, respectively; P = 0.061).
CONCLUSION: At the group level, mean DFA-alpha1 values were numerically close to previously proposed values for VT1 ( approximately 0.75) and VT2 ( approximately 0.50). However, the marked inter-individual dispersion across modalities limits the use of fixed DFA-alpha1 values for individual identification of VT1 and VT2. These findings indicate descriptive group-level correspondence rather than individual-level validity or agreement.

de Lima, F.R., Exercise Psychophysiology Research Group  São Paulo,  Brazil.
de Salles Painelli, V., Canestri, R., Santos, T.M ,.et al

Int J Sport Nutr Exerc Metab 2026 Pages 1-10

PURPOSE: We investigated whether a small dose of alcoholic beer ingested before a running exercise bout impaired performance and changed psychophysiological responses to exercise.
METHODS: After three sessions of familiarizations, 16 healthy and physically active men (25.8 +/- 5.1 years, 175.0 +/- 5.4 cm, and 76 +/- 6.5 kg) performed a 30-min running time trial in a double-blind and placebo-controlled crossover design, after ingesting either beer (alcohol 4.8% v/v; 0.3 g/kg) or nonalcoholic beer (placebo). Performance, cardiopulmonary (oxygen consumption, ventilation, respiratory exchange ratio, and heart rate), and perceptual (perceived exertion, affect, and motivation) variables were assessed throughout the trial and averaged every 5 min during exercise. Running economy was assessed during steady-state running at 8 km/hr. The data were analyzed through t tests and repeated-measures mixed models (p < .05).
RESULTS: The ingestion of beer significantly decreased the average speed by 4.7% (p = .04; d = 0.21) and total distance covered by 4.3% (p = .007; d = 0.26) when compared with placebo. The ingestion of beer also impaired the running economy by 1.1% (p = .01; d = 0.39) and increased respiratory exchange ratio throughout the exercise bout (p = .004, d = 1.07). No beer-by-time interaction effects were detected in cardiopulmonary outcomes (p > .05). CONCLUSIONS: A small dose of alcoholic beer reduced the exercise capacity of healthy individuals, likely due to an impairment in running economy.

Borghi-Silva, A., Cardiopulmonary Physiotherapy Laboratory,  São Carlos, Brazil;
Santos-de-Araujo, A.D., Montalvo, S., Christle, J.W. & Myers, J.

Prog Cardiovasc Dis 2026

BACKGROUND: Peak oxygen consumption (pVO2) has been widely recognized to identify potential pathophysiological mechanisms of exercise intolerance and to stratify risk in patients with heart failure (HF).
AIMS: To develop a non-exercise equation to estimate pVO2 (esVO2) and to determine its association with all-cause mortality.
METHODS: A total of 5176 HF patients (age 48 +/- 17 years) who underwent a CPET for clinical reasons, and were followed between May 2011, and December 1, 2023. Clinical and historical variables and forced expiratory volume in 1-s (FEV(1)) were used in a stepwise multivariate regression analysis to predict pVO2 measured from CPET. Kaplan-Meier curves and Cox proportional hazards analyses were used to determine the association between esVO2 and all-cause mortality.
RESULTS: The first esVO2 model was significantly associated with pVO2 (multiple R = 0.73, P < 0.001). Two other models considered gender separately (male: multiple R = 0.72, P < 0.001 and female (multiple R = 0.70, P < 0.001). A fourth model was proposed when spirometry is not available (age, BMI, resting SBP, HR and gender (multiple R = 0.69, P < 0.001)). The fifth proposed model included history of atrial fibrillation and previous stroke (multiple R = 0.70, P < 0.001). Kaplan-Meier survival curves differentiated patients according to esVO2 and pVO2 </= and > 14 mL/kg(-1) per min(-1). Univariate Cox proportional hazard analyses indicated significant prognostic value when esVO2 and pVO2 were </= 14 mL/kg(-1) per min(-1) (P = 0.001).
CONCLUSIONS: Multivariable nonexercise models combining spirometry and/or clinical variables commonly obtained during a clinical assessment predict pVO2 reasonably accurately in HF.

Di Gioia, G., National Italian Olympic Committee, Rome, Italy.
Ferrera, A., Ginelli, D., Maestrini, V., et al

Eur J Appl Physiol 2026
Headings by Dr Older

Background
Spinal cord injury (SCI) alters autonomic cardiovascular regulation and may limit the translation of cardiac structural adaptation into aerobic performance. Whether spinal cord neurological level modifies cardiac size-exercise coupling in elite athletes remains under investigation.
Methods
We enrolled 178 Paralympic athletes with SCI (33% high SCI, above T6). Athletes underwent transthoracic echocardiography and cardiopulmonary exercise testing. SCI level was analyzed as the main predictor of cardiac structure and exercise performance. Multivariable linear regression models were adjusted for age, sex, and body weight, with additional sensitivity analyses including sport category. Mediation analyses evaluated the role of indexed left ventricular end-diastolic volume (LVEDV/BSA), and interaction models tested effect modification of the LVEDV-VO₂max relationship by SCI level.
Results
Athletes with low SCI exhibited larger LVEDV/BSA (60.6 ± 14.7 vs. 51.9 ± 11.9 mL\m², p < 0.0001) and higher VO₂ max (31.0 ± 9.4 vs. 21.0 ± 9.3 mL\kg\min, p < 0.0001) than those with high SCI. In adjusted models, high SCI independently predicted lower VO₂max (β=-8.88, 95% CI – 11.71 to – 6.05, p < 0.0001) and O₂ pulse (β=-3.38, 95% CI – 5.07 to – 1.70, p = 0.0002), persisting after adjustment for sport category (VO₂: β=-6.64, p = 0.001; O₂ pulse: β=-1.87, p = 0.004). LVEDV/BSA partially mediated the association between SCI level and VO₂ max (β = 0.323 per mL\m², p = 0.0002).
Conclusions
A significant SCI×LVEDV/BSA interaction (β=-1.229, 95% CI – 2.548 to – 1.090, p = 0.002) indicated attenuation of cardiac size-exercise coupling in high SCI. Level of spinal cord lesion independently influences cardiac remodeling and aerobic performance and modifies how cardiac size translates into functional capacity. High-level SCI is associated with a lesion-dependent uncoupling of cardiac structure and exercise performance.

Demers, K., Maastricht University Medical Center+, Maastricht, the Netherlands.
van Kuijk, S.M.J., Pierik, M.J., Jonkers, D., Stassen, L.P.S. & Bongers, B.C.

PLoS One 2026 Issue 10 Pages e0354707

PURPOSE: To develop predictive equations for oxygen uptake at peak exercise (VO2peak) measured during a cardiopulmonary exercise test (CPET) for patients with inflammatory bowel disease (IBD) using submaximal CPET-derived parameters and the steep ramp test, along with demographic and clinical characteristics.
METHODS: This study included patients with IBD in remission or with mild-to-moderate disease activity who performed a CPET and a steep ramp test within 14 days. Submaximal CPET-derived parameters included oxygen uptake (VO2) at the ventilatory anaerobic threshold (VAT) and oxygen uptake efficiency slope (OUES), while the outcome of the steep ramp test was the work rate achieved at peak exercise (WRpeak).
RESULTS: Predictive regression equations with submaximal VO2 at the VAT and with OUES, when combined with age and body fat percentage, explained >89% of the variance in VO2peak (optimism-adjusted R2 = 0.895 and 0.938). Predictive capacity increased when both VO2 at the VAT and OUES were combined in a predictive regression equation, together with age, body fat percentage, and clinically active disease (optimism-adjusted R2 = 0.951). Steep ramp test WRpeak explained 89% of the variance in VO2peak (optimism-adjusted R2 = 0.892).
CONCLUSION: The highly predictive equations developed in this study support the use of the submaximal CPET and the steep ramp test as alternatives for assessing VO2peak in patients with IBD in remission or with mild-to-moderate disease activity in clinical and research settings.

Patil, Pranoti R    Karad, INDIA.
Devi, Poovishnu T

Cureus [Cureus] 2026 Aug 29; Vol. 18 (8), pp. e115400. Date of Electronic Publication: 2026 Aug

Headings by Dr Older

Background Patients undergoing coronary artery bypass grafting (CABG) commonly experience reduced lower-limb strength, impaired balance, decreased functional mobility, and autonomic dysfunction during the postoperative period. These impairments may increase fall risk and limit daily activities. The Otago Exercise Program (OEP) is an evidence-based exercise intervention designed to improve lower-limb strength, balance, and functional performance, while resonance frequency breathing (RFB) has been shown to enhance cardiac autonomic regulation and heart rate variability (HRV). Although both interventions have demonstrated individual benefits, evidence regarding their combined application in phase II cardiac rehabilitation following CABG remains limited. Therefore, this study aimed to evaluate the effects of a combined OEP and RFB intervention on balance, lower-limb strength, functional mobility, and cardiac autonomic function in post-CABG patients.
Objective To evaluate the effects of a combined OEP and RFB intervention on balance, lower-limb strength, functional mobility, and cardiac autonomic regulation as evaluated via HRV in patients undergoing phase II cardiac rehabilitation following CABG.
Materials and methods A single-group pre-test and post-test experimental study was conducted among 40 post-CABG patients aged 40 to 60 years. The eight-week intervention combined supervised OEP multi-component exercises three times per week with daily home-based RFB paced precisely at six breaths per minute for 15 to 20 minutes. Lower extremity functional strength was evaluated by the 30-Second Chair Stand Test, and dynamic mobility was monitored with the Timed Up and Go (TUG) test. Static postural stability was evaluated using the Four-Stage Balance Test. Cardiac autonomic regulation was evaluated using short-term five-minute electrocardiographic (ECG) time-domain metrics, specifically tracked through the mean R-R interval and the root mean square of successive differences (RMSSD).
Results Improvements were observed following the intervention. The TUG test results improved from 17.95 ± 2.86 seconds to 14.68 ± 2.93 seconds (p < 0.001), indicating improvement in functional mobility. The lower limb strength also improved. The 30-Second Chair Stand Test scores went up from 13.03 ± 1.83 to 15.78 ± 2.03 repetitions (p < 0.001). We also saw improvements in balance, tandem stance, and single-leg stance (p < 0.0001). Autonomic function also improved, with an increase in RMSSD from 18.03 ± 2.59 ms to 21.96 ± 2.59 ms (p < 0.001); these findings suggest improved parasympathetic activity.
Conclusions The combined OEP and RFB intervention may support physical function, balance, functional mobility, and autonomic regulation in patients undergoing phase II cardiac rehabilitation after CABG surgery. The intervention appeared to be safe and useful in a home-based rehabilitation setting and may be a helpful approach in cardiac rehabilitation. However, the absence of a control group and separate OEP and RFB groups limits the ability to determine their individual or combined effects. Future studies with appropriate control and separate intervention groups are needed to confirm these findings.

Mainzer, Gur; Padeh Medical Center, Poriya, Israel.
Khourey, Faris;Zucker-Toledano, Merav;et al

European journal of applied physiology [Eur J Appl Physiol] 2026 Sep 28. Date of Electronic Publication: 2026 Sep 28.

• Purpose: To compare oxygen pulse (O₂P) responses during cardiopulmonary exercise testing (CPET) in healthy adults using two ergometers, Treadmill and Cycle ergometer, and to determine the prevalence of O₂P flattening and the modality-specific characteristics of O₂P curve dynamics.
• Methods: Thirty-four healthy adults (29.4 ± 6.9 years; 35% female) completed two maximal CPETs on both Cycle and Treadmill, in a random order within three weeks. O₂P flattening, defined as the absence of a further increase in O₂P despite increasing workload, was assessed visually and confirmed quantitatively.
• Results: Twelve participants (35%) demonstrated O₂P flattening or decline, nine (27%) exclusively during Treadmill testing. A significant group × modality interaction was observed for peak O₂P (p < 0.05), with lower values in participants with flattening than in those showing a continuous rise. (Cycle: 9.9 ± 3.2 vs. 13.6 ± 2.7 ml/min/beat; Treadmill: 11.8 ± 3.7 vs. 16.6 ± 3.7 ml/min/beat). In addition, an O₂ P of ≤ 12.8 ml/beat on the Cycle increased the likelihood of flattening during maximal Treadmill exercise by 7.5 times (OR 7.5, p = 0.03).
• Conclusion: O₂P flattening was more frequently observed during treadmill exercise, indicating that O₂P trajectories are exercise modality dependent. In individuals with low peak O₂P during cycle ergometry, additional assessment using treadmill CPET may offer complementary information.

Djassemi O; Department of Bioengineering,San Diego, USA
Chang AY; McGuire WC; Mitchell E;

ACS Sensors. 11(2):1413-1424, 2026 Feb 27. VI 1

management of sepsis, shock, and metabolic stress, yet current serum
assays remain invasive, intermittent, and resource-intensive. We present a
clinical evaluation of a minimally invasive microneedle-based
electrochemical biosensor for real-time interstitial fluid (ISF) lactate
monitoring. The microneedle biosensor features a platinum working
electrode modified with a lactate oxidase reagent layer and a polyvinyl
chloride anti-fouling membrane for H2O2-mediated amperometry, toward
highly selective and stable ISF lactate detection. In a pilot study of
twenty-one participants across an intensive care unit, emergency
department, cardiopulmonary exercise testing, and controlled laboratory
settings, two enzyme-based microneedle sensors placed on the forearm and
thigh continuously tracked lactate for 4 h. Sensor performance
demonstrated strong agreement with blood lactate assays (r = 0.94), high
diagnostic accuracy for hyperlactatemia (>4 mmol/L; receiver operating
characteristic analysis, area under the curve = 0.95), and minimal bias
(-0.028 mmol/L) over a wide dynamic range (0.7-22.9 mmol/L) with high
selectivity against interferents. No significant ISF-blood differences (p
> 0.05) or adverse events were observed. These findings establish
microneedle biosensors as a promising platform for precision medicine,
with considerable potential to transform sepsis care, guide resuscitation,
and improve assessment of exertional dyspnea.