Does stretching actually do anything, or is it a waste of time?
Stretching demonstrably improves flexibility, and 10 minutes per week is already enough for the maximum effect. For preventing injuries, however, it does not work; eccentric strength training is far more effective for that purpose.
Stretching works if you want to become more flexible. Studies combining data from more than 6,600 adults show that even a single stretching session produces a noticeable improvement in flexibility. You reach the maximum benefit with as little as 10 minutes of stretching per week. Doing more after that adds hardly any extra gain.
For sport, the timing and type of stretching matter. Long static stretches of 60 seconds or more immediately before a training session temporarily reduce your strength and explosive power by around 4 to 5 percent. Short static stretches under 60 seconds have almost no downside. Dynamic stretching, where you swing your limbs loosely through their full range of movement, even has a small positive effect on performance.
Stretching does not prevent injuries: studies show no convincing evidence for this. If you want to prevent hamstring injuries, eccentric strength training, such as the Nordic hamstring exercise, works far better. Studies show a reduction of 57 to 70 percent with that approach.
For specific complaints, stretching can help. People with lower back pain who stretched their hip muscles three times a week for six weeks afterwards had measurably less pain, fewer limitations, and better balance compared with a sham treatment. For shoulder tendon problems, flexibility exercises appear to be more useful than for tendon problems at the knee or ankle, but the studies on this are of low quality. A physiotherapist can help you further here.
Greater flexibility is not always better, by the way. In runners, a certain degree of muscle stiffness is actually associated with a more efficient running technique. The value of stretching therefore depends entirely on your goal.
Based on one large analysis combining 189 studies (more than 6,600 participants) for flexibility, several combined reviews for sports performance and injury prevention, one study in people for lower back pain, and one combined analysis for shoulder tendon conditions. The evidence for injury prevention through stretching is limited and largely comes from people followed over time rather than controlled experiments.
Is sitting a lot harmful, even if I exercise enough?
If you meet the exercise guideline, that largely neutralises the risk of prolonged sitting. If you do not meet it, every additional hour of sitting counts. Prolonged TV viewing is a point of attention even for physically active people.
Does walking do enough to maintain your muscles?
Walking alone is not enough to maintain muscle as you age. Add strength training and ensure adequate protein intake for the best results.
Is walking enough, or do I really need to do strength training too?
Walking is good, but strength training adds something walking cannot: preserving muscle mass, strengthening bones and keeping your metabolism in shape. Even half an hour of muscle-strengthening exercises per week makes a measurable difference.
Is 75 minutes of exercise per week already enough?
75 minutes of vigorous exercise per week already delivers close to the maximum benefit for your lifespan. On top of that, make sure you do not sit for too long at a stretch during the day, as that is a separate risk.
How much exercise do I need to live longer?
The biggest health leap comes from just a little exercise. Going from nothing to 150 minutes per week gives a 31% lower chance of dying early; beyond that the benefit grows somewhat further but then levels off.
Why do myostatin inhibitors produce bigger muscles but not extra strength?
Myostatin inhibitors demonstrably produce larger muscles, but in primates this does not translate proportionally into greater strength, because other inhibitory proteins remain active and take over myostatin's role.