Context & Aims: High-intensity interval training is recognised as a time efficient method to improve metabolic health. Resistance training is also anaerobic in nature (intense work bouts followed by recovery periods), but seemingly is not considered as time efficient or effective for metabolic health. It is therefore important to determine whether differences in the stress and glycaemic responses between modes of anaerobic exercise exist.
Methods: Male (N=9) and female (N=8) recreationally active participants, aged (mean±95% CI) 22±3 years old, participated in this randomised cross-over study. The intensity matched interventions consisted of cycling interval exercise (30 sec at 80% of maximal cycle load (Watts) with two minutes active recovery for 12 repetitions) or resistance exercise (4 sets of 10 repetitions (two minutes recovery) for squats, calf-raises and leg press at 80% of 1RM), conducted at least seven days apart. Both exercise sessions were completed following an overnight fast in the morning, without energy consumption. Venous blood was sampled before and after exercise, and every 30 minutes for two hours following exercise.
Findings: Intervention*time repeated measures ANOVA identified a significant interaction effect for glucose (p=0.003), which peaked at 4.7±0.6 mmol·L-1 30 minutes after cycling intervals. Glucose did not change from pre-resistance exercise (3.2±0.3 mmol·L-1) at any point. Plasma cortisol response was greater following cycling intervals than with resistance exercise (67±47 ng∙ml-1; p=0.01). The insulin response to each intervention was not different (p=0.06), but an increased response was observed in relation to the glucose spike with cycling intervals (41.1±17.5 vs. 0.1±0.2 pmol∙L-1). Interleukin-6 and free fatty acid responses were similar (p>0.11).
Conclusion: Intensity matched cycling interval exercise induced greater levels of stress and glycaemic response than resistance exercise in active, young, apparently healthy individuals. Resistance exercise might benefit glycaemic control in people with glucose metabolism disorders by not inducing a significant glucose spike.