FITNESS SHOULD BOOST your body, not break it down. But physical pressure, friction and tension can easily lead to nagging injuries if you're not careful. Adjust your approach with this guide.

Problem: Burning eyes from swimming

Cause: Even if you suction-pumped your goggles to your eye sockets, chlorine-infused water could still infiltrate during your flip turns.

Fix: Before kicking off the wall, squeeze your outstretched arms against your ears and lead with the top of your head. "This creates a hole in the water that your body can flow through," says swimming coach Richard Quick. You'll minimise drag and keep your goggles glued down.

Problem: Discomfort from the squat bar
Cause: The metal bar, combined with the pressure of the weight and insufficient cushioning, can rub the bony vertebra at the base of your neck.

Fix: Position the bar about two centimetres lower than you usually would, to take pressure off the bony protrusion, says Joseph Warpeha, director of the exercise physiology laboratories at the College of St. Scholastica in the US.

If the bar has no padding, wrap a gym towel around it or swap it for a pair of dumbbells.

Problem: Tender skin after pull-ups

Cause: The portion of thicker flesh just below your fingers jams beneath the pressure of the bar, pinching with every shift in weight.

Fix: To reduce impact, "slide your hand up to the bar to push the fleshy part down and out of the way", says Sean Collins, physical therapy chairman at the University of Massachusetts. Be sure to grip the bar at the crease where your fingers meet your palms, and then wrap your fingers around it.

Problem: Bloody boxing knuckles

Cause: Skilled boxers throw punches fast and frequently. But your skin doesn't always toughen as quickly as your muscles do.

Fix: Build tolerance by hitting the bag harder but less frequently and for shorter periods, explains Dr Julien Baker, a professor of applied physiology at the University of Glamorgan in Wales.

For example, if you usually punch for three minutes at 50 per cent strength, try one minute at full strength until your knuckles can last longer.

Problem: Tennis thumb blisters

Cause: You have those nasty fluid bubbles because you're gripping your racquet too hard, causing friction between your skin and the handle.

Fix: Relax your hand. You'll hit with surprisingly greater racquet speed while reducing post-match pain, says Dr Kris Berg, professor of exercise physiology at the University of Nebraska in the US. You can increase your sessions to Nadal-like lengths after your skin develops tolerance.

Problem: Deadlift shin scrapes

Cause: The rough gripping area of the bar (called the knurling) drags against your legs as you lift, grating your skin.

Fix: Before lift-off, "position your shoulders in front of the bar and your shoulderblades directly over the bar", says Dr Alexander Koch, an associate professor of health and exercise sciences at Truman State University in the US. You'll avoid pulling the bar into your shins, resulting in a cleaner, safer lift.