Physiological Impacts of Type 1 Diabetes on Exercise Performance: A Systematic Review and Narrative Synthesis of the...

Type 1 diabetes (T1D) may influence acute and adaptive responses to exercise training and performance. This systematic review aimed to summarize the evidence comparing exercise performance between individuals with and without T1D and to identify the physiological mechanisms underlying potential differences in exercise performance.

Seven electronic databases were searched for studies comparing exercise performance and underlying physiological mechanisms in individuals with and without T1D. Exercise performance was categorized as aerobic, anaerobic, or skill based, and physiological mechanisms were grouped across cardiorespiratory, neuromuscular, and metabolic domains.

Of 6,563 studies, 28 met the inclusion criteria. Most (k=25) evaluated aerobic exercise performance with time-trial, time-to-exhaustion, and V̇O_2peak tests. Five evaluated anaerobic exercise performance with one-repetition maximum, maximum voluntary contraction, and supramaximal time-to-exhaustion tests. Of the aerobic studies, 88% reported lower aerobic performance in individuals with T1D compared with those without, potentially due to cardiovascular or circulatory mechanisms. Similarly, 60% of the anaerobic studies reported lower anaerobic performance in individuals with T1D compared with those without, potentially due to mitochondrial mechanisms and recovery. Certainty of evidence was assessed using the GRADE tool and was found to be very low.

Current evidence suggests that aerobic exercise performance may be reduced in individuals with T1D. However, the evidence is weak, and these differences seem to be marginal. Suboptimal glycemic management and longer T1D duration may influence physiological responses to exercise and reduce performance capacity. Further research is required to support these conclusions and to determine the impact of T1D on anaerobic and skill-based exercise performance.