As Christmas fades into memory, many of us turn our attention to the new year and the promise of a fresh start. For millions of people, that means joining a gym in the hope of exercising more and improving their health.
Author
- Adam Taylor
Professor of Anatomy, Lancaster University
In the UK alone, more than ten million adults hold gym memberships, and January attendance is around 28% higher than in December as people act on new year resolutions .
And it is a good idea. In the depths of January, physical activity can give you an endorphin kick , caused by the release of natural brain chemicals that improve mood and reduce stress. Regular exercise is also linked to a lower risk of serious conditions including cancer , heart disease , stroke , type-2 diabetes and many more .
The problem is not exercise itself. It is how people start.
The body adapts to exercise gradually. When it is pushed beyond what it is ready for, the risk of injury rises sharply, and pain does not always appear straight away.
Delayed onset muscle soreness (Doms) is the stiffness and tenderness that typically shows up one to three days after unfamiliar or intense exercise. It occurs because exercise causes tiny microscopic damage to muscle fibres, especially when you are returning after a long break or trying a new type of movement .
Doms is common and usually harmless, but it is also a useful warning sign. It signals that your body needs time to adapt before you increase intensity, weight or volume.
Shoulder injuries
Some parts of the body are more prone to injury than others. Joints that move a lot or carry heavy loads are particularly vulnerable.
The shoulder is often top of the list for gym-related injuries. Its wide range of movement is ideal for daily tasks but risky under load. Anatomically, the shoulder connects the arm to the torso and is not designed to carry heavy weight.
When people suddenly start lifting weights or doing pull-ups, strain often falls on the rotator cuff, a group of tendons that stabilise the joint. These tendons are easily irritated, slow to heal and rarely get a rest, as most exercises for the arms, chest, back and even some leg exercises place load through the shoulder.
Knees and lower back
The knees are generally well adapted to everyday movement, but long periods of inactivity weaken the muscles that support the joint. When those muscles waste away, the knee can move in ways it should not. Starting intense exercise on top of this instability raises the risk of serious injury, including damage to the cruciate ligaments.
Going too heavy in weight , too early is a common trigger. Squats, lunges and leg extensions are frequent culprits.
The lower back is another major injury hotspot. Even before exercise begins, the spine already carries a high load from body weight and posture alone. The pelvis links the upper and lower body, so weakness or instability in the legs can transfer strain upwards to the back. Add heavy lifting or poor technique, and the spine can quickly become overloaded.
Lower back pain from muscle strain is so common among weightlifters that it has its own label, "weightlifter's back" . Exercises most often linked to back injuries include sit-ups, squats and deadlifts , burpees and movements that involve twisting while holding weight.
In gyms, free weights are more likely than machines to cause fractures, dislocations and soft tissue injuries. The group most likely to get hurt is not complete beginners, but young men under 41 who already have several months of training and exercise regularly. Confidence, it seems, can be as risky as inexperience.
Home discomforts
Injuries are not limited to gyms. In the US, more than 70,000 emergency department visits over a four-year period were linked to home exercise equipment. Treadmills accounted for 66% of these injuries. Older women were more likely to sustain serious head injuries and were 14 times more likely to require hospital admission.
Among adults over 25, the most common injuries were strains and sprains affecting the legs. For those over 65, stationary bikes were a more frequent source of harm.
Some equipment carries rarer but severe risks. Abdominal rollers have been linked to spinal cord injuries . For people over 40, especially those returning to exercise after years of inactivity, there is also a small but real risk of a heart attack . This is why gradual progression matters.
The good news is that safe options do exist. Many apps and online programmes are designed to build fitness gradually, including for people with existing health conditions . Any movement is better than none, as sedentary behaviour carries its own serious risks.
Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
