TY - JOUR
T1 - Changes in Cardiorespiratory Fitness Following Exercise Training Prescribed Relative to Traditional Intensity Anchors and Physiological Thresholds
T2 - A Systematic Review with Meta-analysis of Individual Participant Data
AU - Meyler, Samuel
AU - Swinton, Paul
AU - Bottoms, Lindsay
AU - Dalleck, Lance
AU - Hunter, Ben
AU - Sarzynski, Mark
AU - Wellsted, David
AU - Williams, Camilla
AU - Muniz, Daniel
N1 - © 2024 The Author(s), under exclusive licence to Springer Nature Switzerland AG. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1007/s40279-024-02125-x
PY - 2024/11/13
Y1 - 2024/11/13
N2 - Background: It is unknown whether there are differences in maximal oxygen uptake (VO
2max) response when prescribing intensity relative to traditional (TRAD) anchors or to physiological thresholds (THR). Objectives: The present meta-analysis sought to compare: (a) mean change in VO
2max, (b) proportion of individuals increasing VO
2max beyond a minimum important difference (MID) and (c) response variability in VO
2max between TRAD and THR. Methods: Electronic databases were searched, yielding data for 1544 individuals from 42 studies. Two datasets were created, comprising studies with a control group (‘controlled’ studies), and without a control group (‘non-controlled’ studies). A Bayesian approach with multi-level distributional models was used to separately analyse VO
2max change scores from the two datasets and inferences were made using Bayes factors (BF). The MID was predefined as one metabolic equivalent (MET; 3.5 mL kg
−1 min
−1). Results: In controlled studies, mean VO
2max change was greater in the THR group compared with TRAD (4.1 versus 1.8 mL kg
−1 min
−1, BF > 100), with 64% of individuals in the THR group experiencing an increase in VO
2max > MID, compared with 16% of individuals taking part in TRAD. Evidence indicated no difference in standard deviation of change between THR and TRAD (1.5 versus 1.7 mL kg
−1 min
−1, BF = 0.55), and greater variation in exercise groups relative to non-exercising controls (1.9 versus 1.3 mL kg
−1 min
−1, BF = 12.4). In non-controlled studies, mean VO
2max change was greater in the THR group versus the TRAD group (4.4 versus 3.4 mL kg
−1 min
−1, BF = 35.1), with no difference in standard deviation of change (3.0 versus 3.2 mL kg
−1 min
−1, BF = 0.41). Conclusion: Prescribing exercise intensity using THR approaches elicited superior mean changes in VO
2max and increased the likelihood of increasing VO
2max beyond the MID compared with TRAD. Researchers designing future exercise training studies should thus consider the use of THR approaches to prescribe exercise intensity where possible. Analysis comparing interventions with controls suggested the existence of intervention response heterogeneity; however, evidence was not obtained for a difference in response variability between THR and TRAD. Future primary research should be conducted with adequate power to investigate the scope of inter-individual differences in VO
2max trainability, and if meaningful, the causative factors.
AB - Background: It is unknown whether there are differences in maximal oxygen uptake (VO
2max) response when prescribing intensity relative to traditional (TRAD) anchors or to physiological thresholds (THR). Objectives: The present meta-analysis sought to compare: (a) mean change in VO
2max, (b) proportion of individuals increasing VO
2max beyond a minimum important difference (MID) and (c) response variability in VO
2max between TRAD and THR. Methods: Electronic databases were searched, yielding data for 1544 individuals from 42 studies. Two datasets were created, comprising studies with a control group (‘controlled’ studies), and without a control group (‘non-controlled’ studies). A Bayesian approach with multi-level distributional models was used to separately analyse VO
2max change scores from the two datasets and inferences were made using Bayes factors (BF). The MID was predefined as one metabolic equivalent (MET; 3.5 mL kg
−1 min
−1). Results: In controlled studies, mean VO
2max change was greater in the THR group compared with TRAD (4.1 versus 1.8 mL kg
−1 min
−1, BF > 100), with 64% of individuals in the THR group experiencing an increase in VO
2max > MID, compared with 16% of individuals taking part in TRAD. Evidence indicated no difference in standard deviation of change between THR and TRAD (1.5 versus 1.7 mL kg
−1 min
−1, BF = 0.55), and greater variation in exercise groups relative to non-exercising controls (1.9 versus 1.3 mL kg
−1 min
−1, BF = 12.4). In non-controlled studies, mean VO
2max change was greater in the THR group versus the TRAD group (4.4 versus 3.4 mL kg
−1 min
−1, BF = 35.1), with no difference in standard deviation of change (3.0 versus 3.2 mL kg
−1 min
−1, BF = 0.41). Conclusion: Prescribing exercise intensity using THR approaches elicited superior mean changes in VO
2max and increased the likelihood of increasing VO
2max beyond the MID compared with TRAD. Researchers designing future exercise training studies should thus consider the use of THR approaches to prescribe exercise intensity where possible. Analysis comparing interventions with controls suggested the existence of intervention response heterogeneity; however, evidence was not obtained for a difference in response variability between THR and TRAD. Future primary research should be conducted with adequate power to investigate the scope of inter-individual differences in VO
2max trainability, and if meaningful, the causative factors.
UR - http://www.scopus.com/inward/record.url?scp=85208976208&partnerID=8YFLogxK
U2 - 10.1007/s40279-024-02125-x
DO - 10.1007/s40279-024-02125-x
M3 - Review article
C2 - 39538060
SN - 0112-1642
JO - Sports Medicine
JF - Sports Medicine
ER -