For blood sugar and cholesterol, lifting alone loses to cardio

For people carrying excess weight, exercise is one of the most reliable ways to improve blood sugar control, insulin sensitivity and cholesterol, all of which shape long-term risk of type 2 diabetes and heart disease. But the practical question of which type of training does this best, endurance work, strength work or a combination of the two, has never had a clear answer. This meta-analysis set out to compare all three head to head on the markers that matter most for cardiometabolic health in overweight and obese adults.

The authors searched the Cochrane, PubMed, Scopus and Web of Science databases for randomised trials testing training interventions in overweight and obese adults. They looked at a wide panel of outcomes: fasting and 2 hour glucose and insulin, glycated haemoglobin (HbA1c, a marker of long-term blood sugar), the HOMA index of insulin resistance, C-peptide, total cholesterol, LDL and HDL cholesterol, and triglycerides. Forty-six studies met the criteria and were pooled, with each training mode compared directly against the others.

Endurance training reduced HbA1c and LDL cholesterol more favourably than strength training. Combined endurance-strength training was broader still, beating strength training on glucose, HbA1c, the HOMA insulin resistance index, total cholesterol, LDL, HDL and triglycerides. Combined training also outperformed endurance training alone on two measures, significantly reducing the HOMA index and triglycerides. The consistent loser across comparisons was strength training on its own, which did not come out ahead on any of the reported cardiometabolic markers. The authors caution that the included trials varied substantially in their results.

This pooled analysis gives the clearest ranking yet for cardiometabolic outcomes in this population: endurance and combined programmes beat strength-only training, and combining the two may edge out endurance alone on insulin resistance and triglycerides. It complements rather than contradicts the muscle-building literature, where resistance training dominates, underlining that different training modes serve different goals. The substantial disagreement between trials leaves the precise size of each advantage open, and the analysis does not settle how much of each mode an optimal combined programme should contain.

If your main concern is blood sugar, insulin sensitivity or cholesterol, this is a reason to think endurance work belongs in the programme, either on its own or alongside lifting, rather than relying on strength training alone. It is also a reason not to frame cardio and weights as rivals: the combined programmes matched or beat everything else across these markers. Strength training still earns its place for other outcomes; this analysis simply says it should not be the whole plan when metabolic health is the goal.