CAN HOT TUBS HELP WITH DELAYED ONSET MUSCLE SORENESS

Delayed Onset Muscle Soreness – the dreaded DOMS!

We’ve all had it – or if you haven’t then you haven’t been pushing yourself. It’s not really the tramp or the ride or the run itself, it’s the next day or days when you’re limping on both legs and any movement requiring muscle activity hurts. It’s called Delayed Onset Muscle Soreness, known in the trade as the dreaded DOMS.

Hot tubs after exercise

We’re not talking about a bit of muscle tenderness after a good work-out, either in the mountains or on the run or bike. We all know that’s normal, and is anyway how muscles get stronger: work them hard enough and they repair with a bonus. And it’s not a specific structural or soft tissue injury, like a joint or ligament strain or muscle tear. Those will be obviously localised, fit clinical criteria for injury, usually with associated swelling and maybe bruising – and you know you’ve torn something.

No, we’re talking about the more general muscle pain and stiffness that has you walking down the steps sideways like a toddler, one step down then bring the other leg to the same step, and crossing your legs by hand when sitting – the DOMS!

The muscles most usually affected are the big drivers of the thighs – the quadriceps – but in more severe cases all the leg muscles can be excruciatingly painful and stiff, especially the hip flexors and calves. In most people this will ease away over a day or a few days of limping around and complaining, but it isn’t that uncommon for it to last nearly a week.

It’s definitely more of a problem with older athletes, and the stiffer your muscles are before you start, the more likely you are to get DOMS after you’ve finished. A long descent in the hills or on the road eccentrically loading the quads is a likely trigger, as is anything with a LOT of sustained effort such as multi-sport, marathons, orienteering, bike races and the like (and there seem to be more of these on offer every year).

I’m a physiotherapist in my 50s – have tramped and climbed and kayaked for 40 years, and when you grew up in Christchurch in the 1950s you got your first bike about age six. I certainly experienced DOMS after epics in Arthurs Pass in my 20s, although it wasn’t labelled as such then. As happens, I got more interested in it professionally after it affected me personally – episodes such as having to lift my legs out of the car by hand after an abortive 10-hour attempt to climb Mt Alta from Wanaka in a day, and just noticing that a lot of lesser tramping activity would leave me sore the next day, when this hadn’t been the case in earlier years. Sigh.

So from published research, patient treatments, using my friends as guinea pigs and personal testing I’ve worked out a few ways to reduce or avoid limping round and moaning the day after something seriously strenuous, e.g. Mt Brewster and back in a day from the Haast Pass road. Also after I invented a new type of hot tub called the Kiwitub, we had a great test rig to investigate the effect of hot water soaking after exercise in all sorts of situations.

So where does the DOMS come from? When you’re moving hard, your heart rate is up and fiercely pumping blood carrying oxygen and nutrients to the muscles. These in turn are working hard on the one-way valves in the veins to send the blood back again, now containing carbon dioxide, lactic acid, and the other products of muscle metabolism.

Now, when you stop moving, the muscle pumping effect driving the return circulation stops immediately, and your heart rate rapidly settles down to a much slower resting level. So in a few minutes that whole strong replenishment and removal of wastes effect has dropped right back. It’s probably from this point that the mild diffuse muscle damage starts to happen, giving rise to stiffness and pain the next day or so: the DOMS. It is an assumption that it’s caused during the activity or race.

But think about it – you’re not particularly sore while you’re still moving. It’s after you’ve stopped, and usually the next day, that the problems happen.

How to avoid it? First a couple of comments on what doesn’t work: warm-down stretching and heavy post-exercise massage. Two groups of physiotherapy students spent 20 minutes stepping up and down off benches at chair height, as fast as they could. One group stretched afterwards, the other didn’t. Both groups were equally sore over the next days (lots!).

So forget about warm-down stretching – it’s already too late! Massage is fairly commonly offered these days after multisport and other races. My impression based on patient feedback is that quite gentle “smoothing’ effleurage-style massage is beneficial, for the circulatory reasons previously outlined. But heavy duty deep sports medicine massage, while highly useful for old stable muscle ‘scarring’ (adhesive fibrosis), has the effect soon after the race of further battering already over-exerted muscles, and increasing the time they take to recover.

So what does work? Firstly, simply use electrolyte replacement drinks, not just water alone. We all know about keeping fluid levels up, but also your working muscles need electrolytes, and if there are more in your system from the drinks, then that’s more for the muscle cells to grab. The powdered types can often be used at half their recommended concentrations. If your body is excreting the excess as shown by bright yellow urine there is obviously more in your system than it can use.

Secondly, if your muscles are tight, the blood can’t circulate through them so well. The benefits of pre-exercise warm-up stretching for injury prevention are suspect these days, but if your quads (for instance) are so chronically tight that you can’t lie on your front and bend your knee up past a right angle, then they won’t be getting the best possible blood supply to the muscle cells. No matter how fit you are, this will have its effect on performance.

It’s not just the slight blood vessel constriction in stiffer tissues – it’s the muscles which shunt the blood in the veins back towards the heart again, and if they’re a bit stiff, they don’t do it quite as well. This is where heavy massage and stretching do have their place – to restore tight muscles to a reasonable length and flexibility, so they work better. But not straight after the race.

The third and much more interesting option is to lounge around in hot water afterwards, preferably with alcohol. There is a sound physiological basis for this. No, really!

If you climb into a hot bath, thermal pool, spa pool or hot tub, your heart rate stays reasonably up and your blood vessels dilate to diffuse the heat. Add a beer or wine (and why wouldn’t you?) and you get some further blood vessel dilation triggered from the alcohol. So the replenishment and flushing effect on the muscles continues at a reasonably high rate, even though you’re no longer working them. This generally means no DOMS afterwards.

A few years ago I invented the Kiwitub – a hot tub we could take up mountains, float, drop off a trailer or ute, and heat up in an hour. This has enabled us to test the effect under rigorous scientific conditions and I am happy to report that there is no significant difference in the benefits obtained between a cold beer or a good Sauvignon Blanc.

You can overdo this, of course. However as an example, a bunch of us have been biking the Pub-to-Pub race for years – 75km from the Garston pub over two mountain ranges to the Bannockburn pub close to my bach in Central Otago with a Kiwitub. No-one’s ever had even a twinge the next day, including me the first time I did it on 70 minutes’ training the previous Wednesday.

The sooner you soak after exercise the better, and an hour or so seems to be about right to avoid DOMS. You’re allowed to stay longer if it seems like a good idea at the time. However a further reminder: don’t do this with an actual injury – the heat will increase the swelling.

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