Figures and data in VO2max prediction based on submaximal cardiorespiratory relationships and body composition in male runners and cyclists: a population study

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3 figures, 6 tables and 3 additional files

Figures

Figure 1

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Flowchart of the preliminary inclusion and exclusion process.

Abbreviations: EA, endurance athlete; CPET, cardiopulmonary exercise testing; SD, standard deviation; TE, treadmill; RER, respiratory exchange ratio; VO₂, oxygen uptake (mL·min⁻¹·kg⁻¹); [La⁻]_b, lactate concentration (mmol·L⁻¹); fR, breathing frequency (breaths·min⁻¹); RCP, respiratory compensation point; HR_peak, peak heart rate (beats·min⁻¹); HR_max, maximal heart rate (bpm). At both stages of the selection, some participants met several (>1) exclusion criteria.

Figure 2

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Performance of prediction equations for VO_2max.

Abbreviations: VO_2max; maximal oxygen uptake; AT, anaerobic threshold; RCP, respiratory compensation point; Max, maximal; Som, somatic. All values are presented in mL·min^–1·kg^–1. Upper panel shows performance for running equations, while the lower panel shows performance for cycling equations. Panel A shows performance of the prediction model for AT; panel B for RCP; panel C for AT and RCP; panel D for somatic-only equation.

Figure 3

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Bland-Altman plots comparing observed with predicted VO_2max in runners derivation and validation cohorts.

Abbreviations: VO_2max; maximal oxygen uptake; AT, anaerobic threshold; RCP, respiratory compensation point; Max, maximal; Som, somatic. All values are presented in mL·min^–1·kg^–1. Upper panel shows performance for running equations, while the lower panel shows performance for cycling equations. Panel A shows performance of the prediction model for AT; panel B for RCP; panel C for AT and RCP; panel D for the somatic-only equation.

Tables

Table 1

Basic anthropometric characteristics for runners.

Variable (unit)	Derivation group n=1998			Testing group n=666			Validation group n=666
Variable (unit)	Mean	CI	SD	Mean	CI	SD	Mean	CI	SD
Age (years)	36.2	35.6–36.9	8.45	35.9	35.5–36.3	8.05	35.5	34.9–36.2	8.14
Height (cm)	180.0	179.6–180.5	6.04	179.4	179.1–179.7	6.13	179.7	179.2–180.2	6.61
BM (kg)	77.7	77.0–78.4	9.35	77.7	77.3–78.1	9.29	77.9	77.1–78.6	10.1
BMI (kg·m^–2)	23.9	23.8–24.1	2.43	24.1	24.0–24.2	2.41	24.1	23.9–24.3	2.56
BF (%)	15.4	15.1–15.7	4.55	15.5	15.3–15.7	4.52	15.4	15.1–15.8	4.55
FM (kg)	12.2	11.9–12.6	4.68	12.3	12.1–12.5	4.65	12.3	11.9–12.7	4.92
FFM (kg)	65.5	65.0–66.0	6.43	65.4	65.1–65.7	6.31	65.6	65.1–66.1	6.86

BM, body mass; BMI, body mass index; BF, body fat; FM, fat mass; FFM, fat-free mass; CI, 95% confidence interval; SD, standard deviation.

Table 2

Basic anthropometric characteristics for cyclists.

Variable (unit)	Derivation group n=656			Testing group n=219			Validation group n=219
Variable (unit)	Mean	CI	SD	Mean	CI	SD	Mean	CI	SD
Age (years)	37.3	36.6–38.0	9.13	37.1	35.9–38.4	9.50	37.6	36.5–38.8	8.46
Height (cm)	179.9	179.4–180.4	6.27	180.1	179.2–181.0	6.96	180.2	179.4–181.0	6.13
BM (kg)	78.8	78.1–79.6	9.80	79.1	77.7–80.5	10.4	79.8	78.4–81.3	10.9
BMI (kg·m^–2)	24.3	24.1–24.6	2.63	24.4	24.0–24.7	2.80	24.6	24.2–25.0	2.96
BF (%)	16.4	15.7–17.1	4.99	16.1	15.7–16.5	4.81	16.2	15.5–16.8	4.87
FM (kg)	13.3	12.6–14.1	5.66	13.0	12.6–13.4	5.27	13.3	12.5–14.0	5.85
FFM (kg)	65.8	64.9–66.6	6.25	65.8	65.4–66.3	6.06	66.6	65.7–67.4	6.58

BM, body mass; BMI, body mass index; BF, body fat; FM, fat mass; FFM, fat-free mass; CI, 95% confidence interval; SD, standard deviation.

Table 3

Cardiopulmonary exercise testing (CPET) characteristics for runners.

Variable (unit)	Derivation group n=1998			Testing group n=666			Validation group n=666
Variable (unit)	Mean	CI	SD	Mean	CI	SD	Mean	CI	SD
rVO_2AT (mL·min^–1·kg^–1)	38.4	38.1–38.8	5.01	38.5	38.3–38.7	4.88	38.1	37.7–38.5	5.16
RER_AT	0.87	0.86–0.87	0.04	0.87	0.86–0.87	0.04	0.87	0.86–0.87	0.04
HR_AT (beats·min^–1)	151.5	150.8–152.3	10.3	151.0	150.6–151.5	10.8	152.0	151.2–152.8	10.8
VE_AT (L·min^–1)	79.1	78.1–80.0	12.2	78.3	77.8–78.9	12.0	77.2	76.3–78.2	12.0
SPEED_AT (km·h^–1)	11.0	10.9–11.1	1.45	11.0	11.0–11.1	1.36	10.9	10.8–11.0	1.42
LA_AT (mmol·L^–1)	2.08	2.02–2.14	0.63	1.80	1.76–1.83	0.62	2.35	2.27–2.42	0.72
rVO_2RCP (mL·min^–1·kg^–1)	47.5	47.0–48.0	5.88	47.7	47.4–48.0	6.15	47.3	46.8–47.8	6.16
RER_RCP	1.00	1.00–1.00	0.04	1.00	1.00–1.00	0.04	1.00	1.00–1.00	0.03
HR_RCP (beats·min^–1)	173.4	172.7–174.1	9.21	173.2	172.8–173.6	9.30	174.3	173.5–175.0	9.50
VE_RCP (L·min^–1)	114.7	113.5–116.0	15.9	113.9	113.1–114.6	16.7	112.7	111.4–114.0	16.2
SPEED_RCP (km·h^–1)	14.0	13.9–14.1	1.77	14.1	14.0–14.1	1.70	13.9	13.8–14.1	1.75
LA_RCP (mmol·L^–1)	4.72	4.63–4.82	1.04	4.40	4.34–4.45	1.04	4.81	4.69–4.93	1.14
rVO_2max (mL·min^–1·kg^–1)	53.8	53.3–54.3	6.67	54.3	54.0–54.6	6.95	53.8	53.3–54.3	7.09

CI, 95% confidence interval; SD, standard deviation; rVO_2AT, oxygen uptake at anaerobic threshold relative to body mass; RER_AT, respiratory exchange ratio at anaerobic threshold; HR_AT, heart rate at anaerobic threshold; VE_AT, pulmonary ventilation at anaerobic threshold; SPEED_AT, velocity at anaerobic threshold; LA_AT, blood lactate concentration at anaerobic threshold; rVO_2RCP, oxygen uptake at respiratory compensation point relative to body mass; RER_RCP, respiratory exchange ratio at respiratory compensation point; HR_RCP, heart rate at respiratory compensation point; VE_RCP, pulmonary ventilation at respiratory compensation point; SPEED_RCP, velocity at respiratory compensation point; LA_RCP, blood lactate concentration at respiratory compensation point; rVO_2max, maximal oxygen uptake relative to body mass.

Table 4

Cardiopulmonary exercise testing (CPET) characteristics for cyclists.

Variable (unit)	Derivation group n=656			Testing group n=219			Validation group n=219
Variable (unit)	Mean	CI	SD	Mean	CI	SD	Mean	CI	SD
rVO_2AT (mL·min^–1·kg^–1)	33.0	32.5–33.4	5.84	33.2	32.4–33.9	5.68	33.7	32.9–34.5	5.89
RER_AT	0.87	0.87–0.87	0.04	0.87	0.87–0.88	0.04	0.87	0.87–0.88	0.04
HR_AT (beats·min^–1)	142.2	141.3–143.1	11.7	140.7	139.1–142.3	11.8	141.2	139.7–142.6	10.8
VE_AT (L·min^–1)	64.9	64.0–65.7	11.0	65.1	63.7–66.5	10.6	67.4	66.0–68.9	11.2
rPOW_AT (W·kg^–1)	2.28	2.24–2.32	0.48	2.27	2.21–2.34	0.48	2.33	2.27–2.39	0.46
LA_AT (mmol·L^–1)	1.86	1.82–1.90	0.51	1.84	1.77–1.90	0.50	1.80	1.74–1.87	0.51
rVO_2RCP (mL·min^–1·kg^–1)	44.0	43.5–44.6	7.38	44.4	43.4–45.4	7.32	44.9	43.8–45.9	7.63
RER_RCP	1.01	1.01–1.01	0.04	1.01	1.01–1.02	0.04	1.01	1.01–1.02	0.04
HR_RCP (beats·min^–1)	168.8	168.0–169.7	10.5	167.7	166.2–169.2	11.3	168.4	167.1–169.6	9.11
VE_RCP (L·min^–1)	106.2	104.8–107.6	17.7	107.6	105.3–109.8	16.8	110.4	107.9–112.9	18.7
rPOW_RCP (W·kg^–1)	3.34	3.29–3.38	0.63	3.33	3.25–3.42	0.63	3.40	3.32–3.48	0.61
LA_RCP (mmol·L^–1)	4.54	4.47–4.61	0.97	4.61	4.48–4.75	1.04	4.47	4.34–4.61	1.03
rVO_2MAX (mL·min^–1·kg^–1)	51.7	51.1–52.4	7.99	52.0	50.9–53.1	8.01	52.3	51.2–53.4	8.08

CI, 95% confidence interval; SD, standard deviation; rVO_2AT, oxygen uptake at anaerobic threshold relative to body mass; RER_AT, respiratory exchange ratio at anaerobic threshold; HR_AT, heart rate at anaerobic threshold; VE_AT, pulmonary ventilation at anaerobic threshold; rPOW_AT, power at anaerobic threshold relative to body mass; LA_AT, blood lactate concentration at anaerobic threshold; rVO_2RCP, oxygen uptake at respiratory compensation point relative to body mass; RER_RCP, respiratory exchange ratio at respiratory compensation point; HR_RCP, heart rate at respiratory compensation point; VE_RCP, pulmonary ventilation at respiratory compensation point; LA_RCP, blood lactate concentration at respiratory compensation point; rPOW_RCP, power at respiratory compensation point relative to body mass; rVO_2max, maximal oxygen uptake relative to body mass.

Table 5

VO_2max prediction equations for cyclists.

Model’s category	Multiple linear regression equation	R²	Derivation group performance		Validation group performance
Model’s category	Multiple linear regression equation	R²	RMSE	MAE	RMSE	MAE
AT	VO_2max = 21.29 + 0.95 * rVO_2AT + 1.74 * rPOW_AT - 0.30 * BF	0.811	3.62	2.89	3.42	2.72
RCP	VO_2max = 8.57 + 1.08 * rVO_2RCP - 0.04 * VE_RCP	0.913	2.12	1.66	2.03	1.64
AT+RCP	VO_2max = 10.57 + 0.98 * rVO_2RCP - 0.12 * BF	0.909	2.26	1.78	2.11	1.72
SOM	VO_2max = 82.36–0.14 * BM - 0.66 * BF - 0.22 * Age	0.43	6.06	4.70	6.11	4.74

AT, equation based on anaerobic threshold; RCP, equation based on respiratory compensation point; SOM, equation based on somatic variables only; R², adjusted R²; RMSE, root mean square error; MAE, mean absolute error (mL·min^–1·kg^–1); VO_2max, maximal oxygen uptake relative to body mass (mL·min^–1·kg^–1); rVO_2AT, oxygen uptake at anaerobic threshold relative to body mass (mL·min^–1·kg^–1); rPOW_AT, power at anaerobic threshold relative to body mass (W·kg^–1); rVO_2RCP, oxygen uptake at respiratory compensation point relative to body mass (mL·min^–1·kg^–1); VE_RCP, pulmonary ventilation at respiratory compensation point (L·min^–1); BF, body fat (%); BM, body mass (kg).

Table 6

VO_2max prediction equations for runners.

Model’s category	Multiple linear regression equation	R²	Derivation group performance		Validation group performance
Model’s category	Multiple linear regression equation	R²	RMSE	MAE	RMSE	MAE
AT	VO_2max = 19.78 + 1.05 * rVO_2AT + 0.94 * SPEED_AT - 0.12 * FFM - 0.06 * VE_AT - 0.07 * HR_AT	0.775	3.43	2.61	3.60	2.74
RCP	VO_2max = 1.98 + 1.03 * rVO_2RCP + 0.23 * SPEED_RCP	0.899	2.0	1.58	2.08	1.60
AT+RCP	VO_2max = 1.98 + 1.03 * rVO_2RCP + 0.23 * SPEED_RCP	0.899	2.0	1.58	2.08	1.60
SOM	VO_2max = 72.37–0.77 * BF - 0.19 * Age	0.35	5.53	4.36	5.54	4.37

AT, equation based on anaerobic threshold; RCP, equation based on respiratory compensation point; SOM, equation based on somatic variables only; R², adjusted R²; RMSE, root mean square error; MAE, mean absolute error (mL·min^–1·kg^–1); VO_2max, maximal oxygen uptake relative to body mass (mL·min^–1·kg^–1); rVO_2AT, oxygen uptake at anaerobic threshold relative to body mass (mL·min^–1·kg^–1); SPEED_AT, velocity at anaerobic threshold (km·h^–1); FFM, fat free mass (kg); VE_AT, pulmonary ventilation at anaerobic threshold (L·min^–1); HR_AT, heart rate at anaerobic threshold (beats·min^–1); BF, body fat (%); rVO_2RCP, oxygen uptake at respiratory compensation point relative to body mass (mL·min^–1·kg^–1); SPEED_RCP, velocity at respiratory compensation point (km·h^–1).