June 2025
Cold vs Hot: Which Post-Exercise Bath Works Best?
We’ve all seen pictures of athletes waist-deep in an ice bath that purportedly reduces inflammation and allows for faster recovery from demanding workouts. And gasped. Whereas hot baths were deemed the gold standard of achey joints – especially of the lower extremities and back – cold water immersion (CWI) was generally relegated to foot and ankle injury management. However, there are very few studies that looked objectively as to whether or not markers of neuromuscular function following intensive exercise-induced muscle damage (EIMD) were improved.
A recent study had 30 physically-active males complete an individualized exercise program designed to induce EIMD. Pre- and post-measures of peak knee torque, strength, and explosive strength (rate of force development: RFD) allowed them to determine whether CWI (at 11 degrees Celsius) improved recovery better than two levels of hot water immersion (HWI: 41 degrees vs 36 degrees Celsius). They also measured pressure pain threshold (PPT) and electromyography (EMG) of the quadriceps to assess the rate of return of EMG rise (REMGR), an indicator of the neuromuscular signaling decline and return after EIMD.
A single session of HWI 41, rather than CWI 11 or HWI 36, improved the recovery of RFD and lowered PPT to baseline after 48 hours. REMGR signals improved more after HWI 41 than after CWI 11.
They concluded that “in athletic contexts where a rapid force development is a key performance determinant, hot bath should be preferred over cold bath.”
In other words, relax in a hot bath of 106 degrees F after a brutal workout. Save the ice for drinking water.
MSSE Dec. 2024
Don’t Let Pain (Alone) Be Your Guide
As we age, our risk of osteoarthritis (OA) in many of our joints increases. Some of the early indicators of OA are swelling, pain, reduced motion, weakness, and disrupted activities of daily living (ADL) and recreational pleasure. But the question science wants answered is, are there objective measures, other than X-rays, that give doctors more evidence from which to make better diagnoses and prescriptions?
From a study of changes in muscle quality using ultrasound to assess echo intensity and shear modulus, a group of Chinese researchers wanted to quantify muscle composition and stiffness in older adults with and without OA of the knee. Additionally, they examined the correlation of these muscle parameters with clinical severity scores (reliable and valid physical therapy tests).
They reported that there was a “weak to moderate correlation found between muscle echo intensity and K-L [Kellgren-Lawrence] grade, as well as between tone and pain score in KOA”. The value in objective measures such as those included in this study is that direct “clinical evaluation of muscle quality [can] assist clinicians in developing appropriate intervention strategies”.
Clearly, the only way to alter muscle quality is with muscle exercise, both cardio and strength training. For more on muscle quality, read this, this, and this.
While this strategy is prima facie obvious, it presents many challenges especially as OA progresses. See the first paragraph above. While difficult, however, it is essential, especially if a joint replacement is in your future. See the first Blue Block below.
Clinical Interventions in Aging Aug. 2024
Tid Bits
A meta-analysis asked if prehab – pre-joint replacement therapy – helps post-surgery recovery. The analysis delineated strength training components such as reps, sets, days/wk and the follow-up period (i.e., short term: 1-3-yrs; mid-term: 5-7-yrs; and long-term: ≥10 yrs). They concluded, based on low- to moderate-quality evidence, that prehab “was favourable for reducing the rate of complications, improving strength, objective function, quality of life, and self-reported function in patients undergoing” joint replacement. JOSPT Apr. 2025
People with type 2 diabetes (T2D) tend to accumulate fat under the skin, around the organs, and intramuscularly (think ‘marbled meat’). Interestingly, healthy cardio athletes also accumulate intramuscular fat (IMF) but theirs is sensitive to insulin whereas the fat with T2D is not. In a comparison of IMF dynamics between T2D patients and cardio athletes, the former had higher unsaturated fat and blunted palmitate and linoleate while the latter had more saturated IMF and very high palmitate kinetics. An 8-wk endurance training reversed fat dynamics of those with T2D to that of athletes. JBJS Oct. 2024
Contrary to the basic American model of body-size obsession, multiple studies have demonstrated that, for older women, longevity is more a function of weight maintenance than it is weight loss. Analyis of data included in the Women’s Health Initiative study of more than 54,000 women, 56% of whom lived longer than 90 years found that weight loss of >5% body weight , especially if unintended, was associated with with lower odds of living long, like into one’s 90s. This Journal of Gerontology (Oct. 2023) report contends that exercise professionals should “remind older adults, and women in particular, of the benefits of exercise for health rather than focusing on weight loss”. Likewise, gaining >5% of baseline weight is not linked to “exceptional longevity” so try to maintain weight as you get older.
