Edexcel GCSE Physical Education · 1PE0
Specification 1.4.2 · Paper 1
Revise: Short-term effects on cardiac functionOne reason is increased venous return, meaning more blood flows back to the heart. Contracting muscles squeeze nearby veins, helping push blood towards the heart. As the heart fills with more blood, its muscle fibres stretch and contract more strongly, increasing the amount pumped out with each beat.