I know you can tear muscles by lifting heavy weights, but how can you tell the difference between pushing yourself to the next stage and taking unnecessary risks?
Mark Mahon, Belfast

Jason Anderson answers: Muscle tears usually occur when you place the unusual stress of a very heavy load on a previously unknown weakness in a specific area or joint of your body. The way to avoid having such weaknesses in the first place is to do some high-repetition, low-weight exercises in an unstable environment such as on a Swiss ball. Once you’ve spent four to six weeks doing this you can start to build up your strength
and muscle mass.

Before starting any muscle-building workout, you should always do an extensive warm-up specific to the exercise. Using a lighter weight and slowly building up to the working weight is a good idea. You can then use pain as your indicator. If something hurts, treat this as a red light and stop. Rather than working through it and suffering the consequences, ask a fitness professional to study your form and tell you where you’re going wrong.