Incremental Exercise Tests in Master Athletes and Untrained Older Adults

Body Mass Index in Master Athletes: Review of the Literature

Background

Masters athletes (MAs) have led a physically active lifestyle for an extended period of time or initiated exercise/sport in later life. Given the benefits of physical activity and exercise we investigated if body mass index (BMI), an indirect health indicator of obesity, was clinically superior in MAs as compared to controls or the general population.

Methods

Seven databases (Medline, PubMed, Scopus, Web of Science, CINAHL, PsycINFO, Cochrane) were electronically searched for studies on BMI (kg/m²) or as a percentage of BMI categories (underweight, normal, overweight, obesity) in MAs.

Results

Of the initial yield of 7,431 papers, 60 studies met our inclusion criteria and were used in this literature review. Studies identified were classified as: endurance sports (n = 14), runners (n = 14), mixed sports (n = 8), cyclists (n = 4), soccer (n = 4) swimmers (n = 3), non-specific (n = 3), orienteering (n = 2), World Masters Games (n = 2) and individual sports (n = 5). Where BMI was presented for the group of MAs the mean was 23.8 kg/m² (± 1.1) with a range from 20.8 kg/m² (endurance runners) to 27.3 kg/m² (soccer players), this was significantly lower (p < 0.001) than controls ( −9.5%, 26.13 ± 1.7 kg/m²). Where gender specific BMI was reported the mean for male MAs was 23.6 kg/m² (± 1.5) (range 22.4 kg/m² endurance to 26.4 kg/m² swimmers) and 22.4 kg/m² (± 1.2) for female MAs (range 20.8 kg/m² mixed to 24.7 kg/m² WMG).

Conclusion

In most, but not all studies the BMI of MAs was significantly lower than controls. A clinically superior BMI affords MAs reduced risk with regard to a number of cardiometabolic diseases, osteoarthritis and certain types of cancers.

A modified D-max method to estimate heart rate at a ventilatory threshold during an incremental exercise test

The purpose of this study was to design a modified D-max method to determine heart rate at a ventilatory threshold (HRVT) and to investigate whether this method would be valid during incremental exercise tests. The HRVT was estimated from a new parameter defined as HR at the maximal difference point between linearly- and quadratically approximated HR trends (modified D-max method). HR and ventilatory gas data for 105 subjects (53 males and 52 females; 38.26 ± 12.06 years; 166.62 ± 8.21 cm; 65.31 ± 11.10 kg) were simultaneously collected during an incremental treadmill test to evaluate the validity of the modified D-max method. Reference HRVTs were manually identified from the ventilatory gas data by an experienced sports physiologist and compared with those estimated by the HR parameter. A strong positive correlation (r = 0.71, p <; 0.01) and a low HR difference of 9.94 ± 7.10 bpm between the reference and estimated HRVTs were obtained. The results indicate that the modified D-max method outperforms the conventional D-max method (r = 0.53, p <; 0.01), the three-piece linear regression lines method (r = 0.42, p <; 0.01), and the parallel straight line slope method (r = 0.57, p <; 0.01). Furthermore, the modified D-max method improves the predictive accuracy of HRVTs by combining its result with subject's age. The combined parameters have a strong positive correlation with the reference HRVTs (r = 0.74, p <; 0.01) and a lower HR difference of 9.40 ± 6.91 bpm. The results suggest that the modified D-max method is highly applicable to predicting HRVTs during incremental exercise tests and also improves HRVT detection accuracy by combining its result with the subject's age.

Effects of aging and training status on ventilatory response during incremental cycling exercise

The aim of this study was to examine the effect of aging and training status on ventilatory response during incremental cycling exercise. Eight young (24 ± 5 years) and 8 older (64 ± 3 years) competitive cyclists together with 8 young (27 ± 4 years) and 8 older (63 ± 2 years) untrained individuals underwent a continuous incremental cycling test to exhaustion to determine ventilatory threshold (VT), respiratory compensation point (RCP), and maximal oxygen uptake (VO₂max). In addition, the isocapnic buffering (IB) phase was calculated together with the hypocapnic hyperventilation. Ventilatory threshold occurred at similar relative exercise intensities in all groups, whereas RCP was recorded at higher intensities in young and older cyclists compared to the untrained subjects. The IB phase, reported as the difference between VT and RCP and expressed either in absolute (ml·min⁻¹·kg⁻¹ VO₂) or in relative terms, was greater (p < 0.01) in both young and older trained cyclists than in untrained subjects, who were also characterized by a lower exercise capacity. Isocapnic buffering was particularly small in the older untrained volunteers. Although young untrained and older trained subjects had a similar level of VO₂max, older athletes exhibited a larger IB. In addition, a higher absolute but similar relative IB was observed in young vs. older cyclists, despite a higher VO₂max in the former. In conclusion, the present study shows that aging is associated with a reduction of the IB phase recorded during an incremental exercise test. Moreover, endurance training induces adaptations that result in an enlargement of the IB phase independent of age. This information can be used for the characterization and monitoring of the physiological adaptations induced by endurance training.