Effects of intensity and amount of exercise on measures of insulin and glucose: Analysis of inter-individual variability

Abstract

AimTo determine the separate effects of exercise amount and intensity on the rate of response for glucose and insulin variables, where rate of response was defined as the number of individuals with improvement in glucose and insulin values that was beyond the day-to-day variability of measurement.MethodsParticipants were 171 sedentary, middle-aged abdominally obese adults who completed a 24-week intervention. Participants were randomly assigned to (1) no-exercise control (n = 51), (2) low-amount, low-intensity exercise (LALI, n = 38), (3) high-amount, low-intensity exercise (HALI, n = 52), or (4) high-amount, high-intensity exercise (HAHI, n = 30). Two-hour glucose, insulin area under the curve (AUC), and fasting insulin were measured during a 2-hour, 75g oral glucose challenge. The day-to-day variability for these measures was calculated to be ±2.2 mmol/L, ±940.2 pmol/L, and ±38.9 pmol/L, respectively.ResultsAt 24 weeks, the number of nonresponders for 2-hr glucose was 98.0%, 86.8%, 94.2%, 86.7% in the control, LALI, HALI, and HAHI groups, respectively. The number of nonresponders for insulin AUC was 88.0%, 75.7%, 75.0%, 80.0% in the control, LALI, HALI, and HAHI groups, respectively. The number of nonresponders for fasting insulin was 88.2%, 84.2%, 84.6%, 93.3% in the control, LALI, HALI, and HAHI groups, respectively. The rate of response was not different between control and any of the exercise groups for any measure (p>0.05).ConclusionThe improvement in glucose and insulin measures did not exceed the day-to-day variability of measurement for approximately 80% of the participants independent of exercise amount or intensity.

Plasma Metabolite Profiles in Response to Chronic Exercise

“…Substantial heterogeneity exists in the individual response to exercise training (6-8) thus, insight into the biochemical pathways involved in exercise offers promise towards early detection of cardiometabolic disease (9) and tailoring exercise “prescriptions” to the individual level (10). …”

Moving beyond threshold-based dichotomous classification to improve the accuracy in classifying non-responders

“…; de Lannoy et al. ; Montero and Lundby ; Astorino TA et al. ), threshold‐based dichotomous classification approaches misclassify individuals who have a high probability of a positive response as non‐responders, and 2) using response CIs with zero‐ and/or SWC‐based thresholds provides more information than dichotomous classification approaches regarding an individual's response.…”

“…; de Lannoy et al. ; Astorino TA et al. ), which fails to consider “non‐response” within the context of meaningful benefit (Swinton et al.…”

“…Much of the recent literature has dichotomously classified individuals as either "responders" or "non-responders" using a pre-determined threshold (Scharhag-Rosenberger et al 2012;Astorino and Schubert 2014;Ross et al 2015;Montero and Lundby 2017) including two times the typical error (2x TE) (Bouchard et al 2012;Bonafiglia et al 2016;Gurd et al 2016;Raleigh et al 2016;Alvarez et al 2017;de Lannoy et al 2017;Astorino TA et al 2018). Although 2x TE is a relatively robust threshold for the classification of "responders" (i.e., the true change for observed responses >29 TE above zero is >90% likely to be positive) (Hopkins 2000a), dichotomous classification of "non-responders" has significant limitations.…”

An appraisal of the SD IR as an estimate of true individual differences in training responsiveness in parallel‐arm exercise randomized controlled trials

“…In 1999 Bouchard et al () published results from the HERITAGE Family Study demonstrating a wide range of peak oxygen consumption ( V O 2 peak) responses across individuals completing an identical exercise training program. Subsequently, a substantial body of literature has emerged reporting variability in the observed pre–post training changes in V O 2 peak (Hautala et al, ; Vollaard et al, ; Sisson et al, ; Astorino and Schubert, ; Wolpern et al, ; Ross et al, ; Raleigh et al, ; Gurd et al, ; Bonafiglia et al, ; Montero and Lundby, ), peak work rate (Vollaard et al, ; Montero and Lundby, ), lactate threshold (Gurd et al, ; Bonafiglia et al, ), and other physiologically meaningful central (MacPherson et al, ; Astorino et al, ; Raleigh et al, ) and peripheral (Vollaard et al, ; McPhee et al, ; Edgett et al, ; Bonafiglia et al, ; deLannoy et al, ; Raleigh et al, ) adaptations. Importantly, although the existence of variability in the observed response to training cannot be questioned (illustrated in Figure ), it remains unclear whether this variability can be attributed to an effect of exercise per se.…”