Does heart rate response confirm the attainment of maximal oxygen uptake in adults 45 years and older?

Abstract

Purpose

To test the efficacy of a plateau in heart rate (HR_plat) as an effective indicator for confirming $\dot{V}{\text{O}}_{2}$max attainment in a middle-aged to older sample.

Methods

Nine men and eleven women (age 60 ± 8.5 years, $\dot{V}{\text{O}}_{2}$max 35.9 ± 9.4 ml/kg/min, N = 20) completed a single $\dot{V}{\text{O}}_{2}$max test on both the treadmill and cycle ergometer.$\dot{V}{\text{O}}_{2}$max was confirmed using a plateau in $\dot{V}{\text{O}}_{2}$ ($\dot{V}{\text{O}}_{2}$_plat) of ≤ 150 ml/min, a verification bout, and HR_plat (≤ 4 bpm).

Results

$\dot{V}{\text{O}}_{2}$_plat occurred in 100% and 95% of participants on the treadmill and cycle ergometer, respectively. Verification criteria ($\dot{V}{\text{O}}_{2}$max during verification ≤ 2% of $\dot{V}{\text{O}}_{2}$max during incremental test) were met by 80% of participants on both modalities. HR_plat was achieved by 90% and 70% of participants on the treadmill and cycle ergometer, respectively.

Conclusion

These results suggest that a verification bout is reliable for confirming $\dot{V}{\text{O}}_{2}$max in older adults on both modalities. In our sample of middle-aged and older adults, $\dot{V}{\text{O}}_{2}$_plat was the most robust method to assess $\dot{V}{\text{O}}_{2}$max when indirect calorimetry is available. Although more research is warranted, when indirect calorimetry is not available, a HR_plat of ≤ 4 bpm may be a useful alternative to get an accurate representation of maximal effort in middle-aged and older adults.