February 2026

The Collagen Peptide Pep Talk

Collagen, technically, collagen peptide supplements  (CPS), are all the rage despite firm scientific rationales. While collagen is made up of amino acids, much as any proteins we eat and use, various studies have shown it to be inferior to those we consume, in foods or supplements. As this newsletter reported, in November 2021, December 2023, April 2025, and July 2025, no studies in the health and fitness journals read by this author have found taking collagen worth your time and money. At an American College of Sports Medicine Annual Meeting in May, 2025, Dr. Luc van Loon, a Dutch researcher of protein  needs in healthy and unhealthy adults, especially older adults, basically declared CPS is a waste of money.

Now some Japanese researchers have approached the topic from a different direction with very positive results. They had 25 healthy, young males consume 10 grams of CPS daily for 16 weeks while another 25 consumed a placebo. Each subject had a MRI of their medial gastrocnemius (the larger of the superficial calf muscles) and Achilles tendon, along with a shear wave elastograph of muscle stiffness. Their calf muscles were also strength tested pre- and post-16 weeks.

While stiffness sounds like an undesirable feature, when it comes to explosive muscle actions, it’s a benefit. And CPS increased calf and tendon stiffness along with rate of torque development. The placebo group did not experience any of the changes of the study group. Also, cross-sectional thickness of the Achilles tendon and isometric torque were unchanged in both groups.

In conclusion, CPS “may serve as an effective nutritional intervention for modifying muscle mechanical properties” that may be useful in power activities, from walking fast to jumping.                   

MSSE Dec. 2025

                                 The Calf Muscle Conundrum:                                     Why Older Runners Miss Them

Muscle stiffness, ordinarily an undesirable thing, is actually beneficial if you’re a competitive runner: stiff lower limb muscles act like tight springs which help you push off faster and more efficiently. See above. Studies have shown, as previous REAL News letters – see here, here, here – had covered, that older runners – and older walkers, too – do not use their calf muscles (plantar flexors) as much as young runners despite years of training. Theories abound, so a group of Chinese researchers tested  the relationship between muscle (co-) activation time and leg stiffness, vertical stiffness (resistance to the center of mass falling too much upon foot strike), and joint stiffness (hip, knee, or ankle).

A study of 29 young, male recreational runners used EMG and complex biomechanical measures to assess leg muscle functions during two runs: at 10 and 12 km/hr. They found that the soleus and lateral gastrocnemius (two of the main calf muscles) had higher activations during the initial contact and mid-stance phases, respectively, which were positively correlated with leg stiffness at higher speeds. The soleus (which is behind the gastroc but is apparently more important than most athletes ever knew about) is extremely involved in the push-off phase whereas the large quadriceps muscle is negatively correlated with ankle joint stiffness.

They concluded that “higher ankle plantar flexor activation contributes to greater lower extremity stiffness regulation during stance, particularly during higher speeds.” Which suggests that high-rep, especially one-leg, heel raises are the key to a more youthful gait!          

MSSE Nov. 2025

Tid Bits