Space travel has revealed just how quickly the human body deteriorates without movement and mechanical load. NASA reports that astronauts in space lose up to 20% of their muscle mass in just 5 to 11 days, and bone mineral density declines by about 1-2% per month, especially in the hips and spine — areas most prone to osteoporotic fractures. 

But you don’t have to go to space to experience similar effects.

Ground-based research shows that inactivity, bed rest, and even low daily movement can rapidly erode muscle mass, strength and bone density, particularly in older adults. A landmark study by Breen et al. (2013) found that healthy people in their late 60s who reduced their step count to 1,400 per day over two weeks lost approximately 2 kg of lean muscle mass, mainly in their legs. They also developed anabolic resistance, with a 26% drop in muscle protein synthesis — meaning their bodies became less capable of repairing and rebuilding muscle, even with adequate protein intake.

This is not just an academic concern. Loss of lean muscle in the legs is directly associated with increased fall and fracture risk, which is a leading cause of hospitalisation, loss of independence and mortality in older populations.

Additional research supports these findings:

• Kortebein et al. (2007) showed that just 10 days of bed rest led to a nearly 1 kg loss of leg muscle in older adults, along with a dramatic decline in strength and mobility.
• Drummond et al. (2012) found that bed rest significantly reduces muscle strength and physical function in older individuals, with measurable losses in lean tissue.
• Paddon-Jones et al. (2010) highlighted that older adults are more susceptible to rapid muscle loss during inactivity compared to younger individuals. Their recommendations include both everyday lifestyle changes and more aggressive interventions during illness or hospitalisation.

Historically, extended bed rest was often prescribed following surgery, back injuries, or acute illness. Today, this practice is increasingly seen as harmful. Medical professionals now encourage early mobilisation — getting patients out of bed and walking or exercising as soon as possible — to prevent rapid muscle atrophy.

Recommendations to Combat Muscle and Bone Loss in Older Adults

1. Move Early and Often: Avoid prolonged periods of inactivity, especially during recovery from surgery or illness.
2. Prioritise Protein: Aim for more than 1.6 grams of protein per kg of body weight daily to support muscle maintenance.
3. Incorporate Resistance Training: Regular mechanical loading of muscles and bones is essential.

OsteoStrong®: A Safe, Evidence-Informed Solution

One highly effective and safe solution for older adults is OsteoStrong®, a resistance-based system that uses a unique system with patented Spectrum machines that assist your body to safely apply pressure to strengthen bones and muscles. These brief, supervised sessions involve self-applied loads to stimulate both bone and muscle adaptation – without the strain or injury risk associated with traditional exercise. 

With over 12 million sessions completed globally, OsteoStrong® has become a trusted option for those seeking to maintain bone density, improve balance, and reduce fall risk, especially in populations who may be frail, time-poor, or recovering from injury.

Tens of thousands of OsteoStrong® members also report that sessions significantly reduce joint and back pain, which in turn makes movement and exercise more accessible. This improvement in mobility often leads to a more active lifestyle – a key factor in maintaining and rebuilding lean muscle mass, especially in the legs and hips where losses are most detrimental.

The bottom line? 

Inactivity – whether due to space travel, illness, or lifestyle — is a serious threat to musculoskeletal health. But with smart interventions, including early movement and safe resistance training like OsteoStrong®, we can help older adults stay strong, mobile, and independent well into the future.