Researchers studied 43 older Japanese adults who did gentle strength exercises twice a week for 12 weeks using elastic bands. They discovered that when people got stronger and walked faster, a special protein in their blood called mercaptoalbumin increased. This protein appears to be a marker of overall health and nutrition. The findings suggest that strength training doesn’t just make muscles stronger—it also creates positive changes in the body at the chemical level that are linked to better physical function and mobility in older adults.

The Quick Take

  • What they studied: Whether gentle strength training exercises change a specific protein in the blood that’s connected to how well older adults can move and function
  • Who participated: 43 healthy older adults (mostly women) with an average age of 67 years living in Japan who were not doing regular exercise programs
  • Key finding: People who improved their walking speed the most also had the biggest increase in mercaptoalbumin protein levels, suggesting the two improvements are connected
  • What it means for you: If you’re middle-aged or older, doing regular strength exercises with elastic bands may improve not just your muscles but also important proteins in your blood that support overall health. However, this is one small study, so talk to your doctor before starting any new exercise program

The Research Details

This was a quasi-experimental study, which means researchers watched what happened when people did a specific exercise program, but didn’t have a comparison group that didn’t exercise. The 43 participants did supervised strength training twice a week for 12 weeks using elastic bands—exercises that don’t require heavy weights or special equipment. Before and after the training, researchers measured how fast people could walk, checked their blood for various proteins and nutrients, and asked about their diet. They then used statistical analysis to see if changes in walking speed matched up with changes in the blood protein called mercaptoalbumin.

Understanding the biological mechanisms behind why exercise helps older adults is important because it can help doctors and fitness professionals design better programs. By measuring specific proteins in the blood, researchers can track whether exercise is creating positive changes at the cellular level, not just visible improvements in strength and speed.

This study has some strengths: it measured multiple factors (walking speed, blood chemistry, diet), used supervised training to ensure people did the exercises correctly, and tested people before and after the program. However, the study was small (only 43 people, mostly women), had no control group to compare against, and was done only in Japan with older Japanese adults, so results may not apply equally to other populations. The findings are interesting but should be confirmed by larger studies.

What the Results Show

The main discovery was that mercaptoalbumin—a special form of a blood protein called albumin—increased in people who improved their walking speed the most through strength training. Before the training started, people with higher mercaptoalbumin levels already walked faster than those with lower levels. After 12 weeks of training, the people whose mercaptoalbumin increased the most were also the ones who showed the biggest improvements in their maximum walking speed. This connection was statistically significant, meaning it’s unlikely to be due to chance alone. The researchers found that for every increase in mercaptoalbumin, there was a corresponding improvement in how fast people could walk at their maximum effort.

The study also looked at usual walking speed (how fast people normally walk) and found it was connected to mercaptoalbumin levels before training began. This suggests that mercaptoalbumin might be a useful marker of overall physical health in older adults. The researchers also collected information about what people ate, though the abstract doesn’t detail how diet related to the changes observed.

Previous research has suggested that mercaptoalbumin is related to physical function and nutrition status, but this appears to be one of the first studies to show that it changes along with improvements from strength training. The findings support the growing understanding that exercise creates beneficial changes throughout the body, not just in muscles. Other studies have shown that strength training improves walking speed and physical function in older adults, and this research adds a new piece by identifying a specific blood protein that may be involved in those improvements.

The study was small with only 43 participants, mostly women (33 women and 10 men), so results may not apply equally to men or to people from other countries. There was no control group that didn’t exercise, so we can’t be completely sure the changes were caused by the training rather than other factors like seasonal changes or natural variation. The study only lasted 12 weeks, so we don’t know if the benefits continue longer or if the improvements are permanent. The elastic band exercises were low-load (gentle), so results might be different with more intense strength training.

The Bottom Line

If you’re middle-aged or older and generally healthy, adding gentle strength training exercises twice a week using elastic bands appears to be beneficial for walking speed and may create positive changes in blood proteins related to health. Start with a qualified trainer to learn proper form. This evidence is moderate in strength—it’s promising but needs confirmation from larger studies. Always consult your doctor before starting a new exercise program, especially if you have existing health conditions.

This research is most relevant to healthy middle-aged and older adults looking to maintain or improve their physical function and mobility. It’s particularly interesting for people who prefer gentle, equipment-light exercises. People with serious health conditions, severe mobility limitations, or those taking medications that affect protein metabolism should discuss these findings with their healthcare provider. Younger adults may see different results since this study focused on older populations.

Based on this study, you might expect to see improvements in walking speed within 12 weeks of doing strength training twice weekly. However, the changes in blood proteins may take several weeks to become noticeable. Individual results will vary based on starting fitness level, consistency with exercise, nutrition, and overall health.

Want to Apply This Research?

  • Track walking speed weekly using a timed 6-meter walk test (time how long it takes to walk 20 feet at your normal pace, then at your fastest pace). Record this in your app along with your strength training sessions to see if improvements correlate over time.
  • Set a goal to complete two supervised or guided strength training sessions per week using elastic bands or body-weight exercises. Log each session in the app with the exercises performed, duration, and how you felt. This creates accountability and helps you see patterns in your progress.
  • Create a monthly check-in where you re-test your walking speed and note any changes in how easily you move through daily activities (climbing stairs, getting up from chairs, carrying groceries). Track this alongside your exercise consistency to see if the relationship between training frequency and mobility improvements holds true for you personally.

This research describes findings from a single small study and should not be considered medical advice. The study was conducted in a specific population (older Japanese adults) and may not apply equally to all groups. Before starting any new exercise program, especially if you have existing health conditions, take medications, or have concerns about your mobility, consult with your healthcare provider or a qualified fitness professional. The blood protein changes described in this study are interesting but require confirmation through larger research before being used as a standard health marker. Individual results will vary based on personal health status, genetics, nutrition, and consistency with exercise.