1. Janna Newton, Tatiane Piucco, Juan M. Murias
Characterization of Cardiovascular Responses to Maximal and Sub-Maximal Exercise throughout the Adult Lifespan in Trained Men
Janna Newton, Tatiane Piucco, Juan M. Murias
Exercise and Aging Laboratory, Faculty of Kinesiology, University of Calgary
Results
Table 1: Subject characteristics of eight young males and ten older males participating in maximal oxygen uptake and oxygen kinetics sessions
Background
Subject characteristics are described in Table 1.
As shown in Figure 1, the VO2max of young participants (3.91 ± 0.37 L‧min-1 ) was significantly higher (p <0.05) than older participants (3.19 ± 0.40 L‧min-1 ).
PPO was significantly (p < 0.05) different between young participants with values of 377 ± 46 W and older participants 303 ± 38 W at maximal exercise.
During the moderate intensity transition session, the τ V O 2 was not significantly (p > 0.05) different between the young (, 16.3 ± 3.9 s) and older (, 20.9 ± 7.4 s).
Maximal oxygen uptake (VO2max) has been associated with important health outcomes including being able to perform activities of daily living, morbidity and mortality1.
Exercise can be used as primary prevention in 35 chronic conditions more common in the older population.
With age, VO2max decreases because of the decrease in maximal heart rate.
VO2 kinetics is representative of the reliance on the anaerobic system until steady state is achieved with an increased workload often to the moderate intensity domain.
VO2 kinetics is dependent on training status, health conditions and age2.
 Variables
YT (Mean ± SD)
OT (Mean ± SD)
Age (years)
26 ± 3
65 ± 3
Height (cm)
176 ± 5
178 ± 6
Weight (kg)
69 ± 10
Body fat (%)
13 ± 3
16 ± 3
VO2max (mL/min/kg)
3.91 ± 0.37
3.19 ± 0.40*
Discussion
Reduction in maximal cardiac output (CO) diminishes the VO2max in endurance exercise capacity in older adults
The slowing of oxygen uptake kinetics commonly seen in older individuals is not necessary due to aging, but the level of fitness, which an important modulator.
Improved distribution of blood flow to the active tissues is believed to be responsible for the fast V O 2 kinetics observed in the older individuals
Objective *
To evaluate the rate of cardiovascular decline between young and older adults, and to what extent exercise training can reduce loss of function in chronically trained men.
Methods
Conclusion
Young ( years, n = 8) and older (60 – 75 years, n = 10) subjects were recruited.
Aerobic exercise consisted of 3 square wave transitions from a 6 minute 20 W baseline to 90% of the gas exchange threshold (GET).
Body composition was measured using dual X-ray absorptiometry
Direct measure of VO2max via a continuous ramp incremental (RI) test.
Maximal oxygen uptake (VO2max), peak power output (PPO), body fat percentage, and time constant of VO2 (τVO2) were evaluated over two sessions.
VO2max was defined as the highest 30s rolling average of the RI protocol
Figure 1. Average VO2max in 8 young and 10 older participants. Bars represent the mean VO2max and the error bars represent standard deviation.
With aging PPO and VO2max decrease despite chronic endurance training.
τVO2 can be preserved with chronic, endurance training in older adults.
Acknowledgements
We would like to thank the Markin Undergraduate Student Research Program in Health and Wellness Research for providing studentship support for Janna Newton. Thank you to the graduate students and staff of the Exercise and Aging Laboratory for your continuous support.
References
1. Shah, U., Contractor, N., & Mehta, K. (2017). Preoperative Pulmonary Function Tests in COPD Patients Posted For Major Upper Abdominal Surgeries: Evaluation of Postoperative Pulmonary Complications. National Journal of Integrated Research in Medicine.
2. Murias, J. M., & Paterson, D. H. (2015). Slower VO2 kinetics in older individuals: Is it inevitable? Medicine and Science in Sports and Exercise, 47(11), 2308–
Figure 2. Average τVO2 in 8 young and 10 older participants. Bars represent the mean τVO2 and the error bars represent standard deviation.