For a spacious sleeping set up, the Therm-a-Rest Boost 650 is a great, adjustable option.
For people in larger bodies or those who like a more spacious sleeping set up, the Therm-a-Rest Boost 650 20F/-6C is a versatile and adjustable sleeping bag is a great option. While not the lightest on the market, well thought out design features make it a great choice for those who prioritise comfort over weight.
Steph Wetherell recommends
Overall, a brilliant bag for those who want or need a more spacious bag, with some well-designed features that add versatility and comfort.- inclusive sizing
- spacious
- arm holes
- bulky
- heavier than some others
| Quick specs |
|---|
| Price: $299.95 / £345 (available from OutdoorAction) Weight: Regular (1.3 kg), Regular Wide (1.6kg) including stuff sack (72g) Fill: 649g (regular) | 909g (regular wide) 650fp hydrophobic down Shell: 20D 100% Recycled Nylon Rip Stop Construction: Lateral box wall baffles Zip: 2-way full length YKK anti snag zipper Length: 168cm (short), 183cm (regular), 198cm (long) Rating: 0 C (comfort), -6 C (limit) Sizes: Short, Short Wide, Regular, Regular Wide, Long, Long Wide (wide fit available from vampireoutdoorgear.com) Women/Men’s version: Unisex cascadedesigns.com |
Thermarest are known for their spacious sleeping bags but the Boost goes further, offering a ‘Wide’ fit that provide an additional 12 inches of space in the shoulder and 14 inches in the hip. In addition, the integrated ‘WarmZip’ system allows you to regular your temperature by opening or closing an enclosed baffle that runs down the centre of the bag.
In addition to offering an approximate additional 6C of warmth when closed, it also provides a further 7 inches of space across the hip when open. I tested the Regular Wide to get a sense of how roomy it was, and 76 inch shoulder and 67/74 inch hip (WarmZip closed/open) make this the most spacious packable bag I’m aware of, though it did take some wrangling to get into the stuff sack.
With the WarmZip done up, I was plenty warm enough at almost freezing temperatures, and I found opening the WarmZip a remarkably effective way to help regulate my temperature in the middle of the night. Another nice addition is the zippable arm holes that can be operated from inside the bag, meaning your core can be snug and warm inside the bag while your arms are free – perfect for people like me who read in their tent, but also meaning you can operate the Warmzip without unzipping the wider bag.
There’s some other nice features – a small internal pocket and the hood cinches in nicely, although the toggle is a little fiddly. Overall, a brilliant bag for those who want or need a more spacious bag, with some well-designed features that add versatility and comfort.
How we tested
Steph tested these sleeping bags in South Wales during the autumn and spring months. She is a size 20 and 5’10 tall so favours a spacious bag, and is also a cold sleeper. She’s put together a guide to the best plus-size gear – and you can compare this model with other bag in our guide to the best sleeping bags.
